ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (1,270)
  • Industrial Chemistry and Chemical Engineering  (1,133)
  • biofilm  (72)
  • adsorption  (65)
  • Process Engineering, Biotechnology, Nutrition Technology  (1,270)
  • 1
    Electronic Resource
    Electronic Resource
    Modeling the extraction of perylene from spiked soil material by dense carbon dioxide
    Amsterdam : Elsevier
    The @Journal of Supercritical Fluids 7 (1994), S. 265-274 
    Details
    ISSN: 0896-8446
    Keywords: PAH ; adsorption ; carbon dioxide ; contaminated soil ; solubility ; supercritical-fluid extraction
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0896-8446(94)90014-0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Characterization of accumulated biomass in anaerobic filter treating various types of substrates
    Amsterdam : Elsevier
    Bioresource Technology 47 (1994), S. 275-282 
    Details
    ISSN: 0960-8524
    Keywords: Anaerobic filter ; acetate ; biofilm ; biomass ; egg albumin ; glucose ; growth yield ; methane production ; two-phase process
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0960-8524(94)90191-0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Adsorption of heavy metal ions by chemically modified Pinus pinaster bark
    Amsterdam : Elsevier
    Bioresource Technology 48 (1994), S. 251-255 
    Details
    ISSN: 0960-8524
    Keywords: Pinus pinaster bark ; adsorption ; cation exchange ; metal cations ; water treatment
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0960-8524(94)90154-6
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effective diffusivities of volatile fatty acids in methanogenic biofilms
    Amsterdam : Elsevier
    Bioresource Technology 48 (1994), S. 155-161 
    Details
    ISSN: 0960-8524
    Keywords: Effective diffusivity ; anaerobic digestion ; biofilm ; bioflocs ; fatty acids ; methane ; reaction-diffusion
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0960-8524(94)90203-8
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Coirpith, an agricultural waste by-product, for the treatment of dyeing wastewater
    Amsterdam : Elsevier
    Bioresource Technology 48 (1994), S. 79-81 
    Details
    ISSN: 0960-8524
    Keywords: Dyeing wastewater ; adsorption ; carbonised coirpith waste ; pH effect
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0960-8524(94)90141-4
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A thermodynamic approach for predicting retention time characteristics in supercritical fluid chromatographs
    Amsterdam : Elsevier
    The @Journal of Supercritical Fluids 3 (1990), S. 71-77 
    Details
    ISSN: 0896-8446
    Keywords: adsorption ; molecular separations ; near-critical phenomena ; supercritical fluid chromatography
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0896-8446(90)90010-J
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Frequency change of a quartz crystal microbalance at the supercritical condition of carbon dioxide
    Amsterdam : Elsevier
    The @Journal of Supercritical Fluids 7 (1994), S. 289-292 
    Details
    ISSN: 0896-8446
    Keywords: adsorption ; quartz crystal microbalance ; resonance frequency
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0896-8446(94)90017-5
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Activity coefficients of adsorbed mixtures (1995)
    Springer
    Adsorption 1 (1995), S. 103-112 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; mixtures ; activity coefficients ; zeolites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Experimental and simulated data for adsorption of gas mixtures on energetically heterogeneous surfaces like activated carbon and zeolites exhibit negative deviations from ideality. The deviations are large in some cases, with activity coefficients at infinite dilution equal to 0.1 or less. Similar molecules form ideal mixtures, but molecules of different size or polarity are nonideal. Equations for bulk liquid mixtures (Wilson, Margules, etc.) do not apply to isobars for adsorbed mixtures. A two-constant equation for activity coefficients as a function of composition and spreading pressure is in good agreement with theory, simulation, and experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704999
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Molecular simulation of binary mixture adsorption in buckytubes and MCM-41 (1996)
    Springer
    Adsorption 2 (1996), S. 23-32 
    Details
    ISSN: 1572-8757
    Keywords: GCMC ; DFT ; adsorption ; MCM-41 ; buckytube ; simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract MCM-41 and buckytubes are novel porous materials with controllable pore sizes and narrow pore size distributions. Buckytubes are carbon tubes with internal diameters in the range 1–5 urn. The structure of each tube is thought to be similar to one or more graphite sheets rolled up in a helical manner. MCM-41 is one member of a new family of highly uniform mesoporous silicate materials produced by Mobil, whose pore size can be accurately controlled in the range 1.5–10 nm. We present grand canonical Monte Carlo (GCMC) simulations of single fluid and binary mixture adsorption in a model buckytube, and nonlocal density functional theory (DFT) calculations of trace pollutant separation in a range of buckytubes and MCM-41 pores. Three adsorbed fluids are considered; methane, nitrogen and propane. The GCMC studies show that the more strongly adsorbed pure fluid is adsorbed preferentially from an equimolar binary mixture. Ideal adsorbed solution theory (IAST) is shown to give good qualitative agreement with GCMC when predicting binary mixture separations. The DFT results demonstrate the very large increases in trace pollutant separation that can be achieved by tuning the pore size, structure, temperature and pressure of the MCM-41 and buckytube adsorbent systems to their optimal values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00127095
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Simulation of adsorption of liquid mixtures of N2 and O2 in a model faujasite cavity at 77.5 K (1996)
    Springer
    Adsorption 2 (1996), S. 41-50 
    Details
    ISSN: 1572-8757
    Keywords: Monte Carlo simulation ; Gibbs-Duhem integration ; adsorption ; liquid mixtures ; faujasite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Grand canonical Monte Carlo simulations of adsorption of N2 and O2 and their mixtures in a model zeolitic cavity 14 Å in diameter were performed at 77.5 K for pressures ranging from zero up to saturation, where the adsorbed phase is in equilibrium with coexisting vapor and liquid phases. The same intermolecular potential functions were employed for gas-gas interactions in the vapor, liquid, and adsorbed phases. The gas-solid interaction potential includes dispersion-repulsion energy, induced electrostatic energy, and an ion-quadrupole term to model the interaction of the electric field in zeolites like NaX with polar molecules like N2. The simulation of the coexisting vapor and liquid phases reproduces the saturation properties of pure liquid oxygen and nitrogen at 77.5 K. Activity coefficients in the adsorbed phase derived from simulations as a function of cavity filling and composition show negative deviations from Raoult's law, even though the non-idealities in the bulk liquid phase have the opposite sign. The simulation of the surface excess isotherm for adsorption from liquid mixtures exhibits preferential adsorption of N2 and has the commonly-observed quadratic shape skewed toward the more strongly adsorbed component. Micropore condensation is observed for oxygen but not for nitrogen. The condensation of oxygen is similar to a first order phase transition but because of the small number of molecules that can fit into a micropore, coexistence of the two phases is replaced by oscillations between gas- and liquid-like densities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00127097
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Molecular dynamics simulations of osmosis and reverse osmosis in solutions (1996)
    Springer
    Adsorption 2 (1996), S. 95-101 
    Details
    ISSN: 1572-8757
    Keywords: osmosis ; reverse osmosis ; adsorption ; diffusion ; molecular dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Computer simulation studies using the method of molecular dynamics have been carried out to investigate osmosis and reverse osmosis in solutions separated by semi-permeable membranes. The method has been used to study the dynamic approach to equilibrium in such systems from their initial nonequilibrium state. In addition density profiles of both the solute and solvent molecules have been investigated, especially near the walls for adsorption effects. Finally the diffusion coefficients and osmotic pressure have also been measured. Our results show both osmosis and reverse osmosis, as well as a smooth transition between the two when either the solution concentration is changed, or the density (pressure) difference between the solvent and solution compartments is varied. We believe this new method can be used to improve our understanding of these two important phenomena at the molecular level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00127103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Adsorption and characteristics of base-treated pillared clays (1996)
    Springer
    Adsorption 2 (1996), S. 227-235 
    Details
    ISSN: 1572-8757
    Keywords: pillared clays ; heavy metal ions ; adsorption ; cation exchange capacity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effect of base treatment on the cation exchange capacity (CEC) of pillared clays and their adsorption isotherms for Cu2+, Cr3+ and Pb2+ have been investigated. Results indicate that although the CEC of pillared clays are only about 15% of that of the parent clays, a large fraction of the native clays CEC may be recovered by treatment with base. The fraction of the CEC recovered depends upon the base strength, its concentration, and the temperature. Contrary to previous suggestions the mechanism of recovery is related to the destruction of pillars which is accompanied by the loss of surface area. It is possible under conditions specified to prepare these base treated pillared clays as a new class of useful, regenerable adsorbent for heavy metal adsorption from aqueous solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00128304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Comparison of molecular simulation of adsorption with experiment (1996)
    Springer
    Adsorption 3 (1996), S. 107-115 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; molecular simulation ; isosteric heat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Experimental measurements of adsorption yield the surface excess. The Gibbs surface excess is the actual or absolute amount of gas contained in the pores less the amount of gas that would be present in the pores in the absence of gas-solid intermolecular forces. Molecular simulation of adsorption yields the absolute amount adsorbed. Comparison of simulated adsorption isotherms and heats of adsorption with experiment requires a conversion from absolute to excess variables. Molecular simulations of adsorption of methane in slit pores at room temperature show large differences between absolute and excess adsorption. The difference between absolute and excess adsorption may be ignored when the pore volume of the adsorbent is negligible compared to the adsorption second virial coefficient (V≪B 1s ).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01650234
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Theoretical basis for the Dubinin-Radushkevitch (D-R) adsorption isotherm equation (1997)
    Springer
    Adsorption 3 (1997), S. 189-195 
    Details
    ISSN: 1572-8757
    Keywords: Dubinin-Radushkevitch equation ; Dubinin-Astakhov equation ; adsorption ; micropore adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Dubinin-Radushkevitch (D-R) equation, which was originally proposed as an empirical adaptation The Polanyi adsorption potential theory, has been the fundamental equation to quantitatively describe the adsorption gases and vapors by microporous sorbents. The equation, based on the postulate that the mechanism for adsorption in micropores is that of pore-filling rather than layer-by-layer surface coverage, generally applies well to adsorption systems involving only van der Waals forces and is especially useful to describe adsorption on activated ???. The ability of the D-R equation to describe gas adsorption on porous materials has inspired many to undertake studies, both experimental and theoretical, to explain the source of the success of the D-R equation in ??? of molecular properties at the gas-solid interface. In many cases, these studies have led to extensions or modifications of the original D-R equation. Many of these attempts and the resulting extensions are reviewed and discussed here. Recently, an isotherm equation was derived for adsorption of gases and vapors on microporous ??? from statistical mechanical principles. It was shown that the D-R equation is an approximated form of this potential theory isotherm. This development is also reviewed and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01650130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Adsorption of SO2 from Wet Mixtures on Hydrophobic Zeolites (1998)
    Springer
    Adsorption 4 (1998), S. 25-33 
    Details
    ISSN: 1572-8757
    Keywords: hydrophobic zeolites ; breakthrough curves ; adsorption ; binary mixtures ; modeling ; overall mass transfer ; roll-up
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Breakthrough curve measurements of SO2 and water vapor were carried out on a number of selected mordenite and pentasil zeolites from their binary and ternary mixtures with CO2 at 50 and 100°C. SO2 capacities of these samples were found to be significantly reduced by the presence of water. Competitive adsorption led to unusually high overshoot peaks of SO2 breakthrough curves. On the other hand, SO2 was found to displace water on the samples with very high silica to alumina ratio. A linear driving force, isothermal model was used to predict the breakthrough curves. Langmuir and extended Langmuir equilibrium models were used to describe the equilibrium properties of water and SO2, respectively. The overall mass transfer resistance obtained from the model was compared to the values calculated from a simplified biporous adsorbent model to shed some light on the adsorption kinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008883219403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Neural Network Modeling of Adsorption of Binary Vapour Mixtures (1999)
    Springer
    Adsorption 5 (1999), S. 183-192 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; activated carbon ; neural network ; ideal adsorption solution theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Three neural network models were used for prediction of adsorption equilibria of binary vapour mixtures on an activated carbon. The predictions were compared both with published experimental data and calculated values from the Ideal Adsorption Solution (IAS) model. The neural network was trained using both binary and single component experimental adsorption data. Even for a limited number of data points (about 60) the network models were capable of approximating experimental data very precisely.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008977528474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Pressure Effects in Adsorption Systems (1999)
    Springer
    Adsorption 5 (1999), S. 261-278 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; concentrated systems ; pressure transients ; flow transients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A study of the occurrence of large pressure and flow transients when a strongly adsorbed gas is fed to a column which is initially loaded with a lightly adsorbed gas is presented here. Under certain conditions, these transients can cause premature breakthrough and change the shape of the breakthrough curve. This will result in improper estimation of adsorption parameters by the dynamic column loading method and lower apparent adsorption capacity in a full scale unit. A data acquisition system was used to record the pressure and flow transients. An isothermal PDE model developed to study these transients agreed reasonably well with the nonisothermal experimental results. The PDE model predicts that pressure and flow transients will occur during step and pulse~tests conducted to obtain adsorption and mass transfer parameters by the chromatographic method. For instance, lower adsorption capacity will be realized during step tests due to lowering in column pressure. Oscillations were observed when columns are connected in series. The PDE model also predicts these oscillations. Simulations indicate that the extent of oscillations is dependent on the dead volume between columns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008955828900
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Methane Adsorption on Planar WS2 and on WS2-Fullerene and -Nanotube Containing Samples (2000)
    Springer
    Adsorption 6 (2000), S. 169-174 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; WS2 ; nanotubes and fullerenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption-desorption cycles were measured for methane on non-irradiated WS2, and on irradiated WS2 (which contained, in part, WS2 fullerenes and nanotubes). Both types of samples were further subdivided into three sets: one set received no further treatment, another set was heated under vacuum, and the last set was acid-treated and heated. The specific surface area was determined for each set; so was the presence or absence of a hysteresis loop in the adsorption-desorption cycles. The results of these two groups of measurements were correlated with the space available for adsorption. The implications of the results for the experimental determination of the dimensionality of gas adsorbed at the interior of nanotubes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008921602962
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Why Does the Linear Driving Force Model for Adsorption Kinetics Work? (2000)
    Springer
    Adsorption 6 (2000), S. 137-147 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; kinetics ; linear driving force model ; process design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Linear Driving Force (LDF) model for gas adsorption kinetics is frequently and successfully used for analysis of adsorption column dynamic data and for adsorptive process designs because it is simple, analytic, and physically consistent. Yet, there is a substantial difference in the characteristics of isothermal batch uptake curves on adsorbent particles by the LDF and the more rigorous Fickian Diffusion (FD) model. It is demonstrated by using simple model systems that the characteristics of the adsorption kinetics at the single pore or the adsorbent particle level are lost in (a) evaluating overall uptake on a heterogeneous porous solid, (b) calculating breakthrough curves from a packed adsorbent column, and (c) establishing the efficiency of separation by an adsorptive process due to repeated averaging of the base kinetic property. That is why the LDF model works in practice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008965317983
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    A Grand Canonical Monte-Carlo Simulation Study of Xenon Adsorption in a Vycor-like Porous Matrix (2000)
    Springer
    Adsorption 6 (2000), S. 241-249 
    Details
    ISSN: 1572-8757
    Keywords: silical glasses ; CPG ; Vycor ; adsorption ; capillary condensation ; molecular simulation ; Monte-Carlo ; SANS ; SAXS ; fractals ; surface roughness ; Porod's law ; Gurvitch rule ; hysteresis loop
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract We have performed atomistic Grand Canonical Monte-Carlo (GCMC) simulations of adsorption of xenon in a Vycor-like matrix at 195 K. The disordered mesoporous network is obtained by applying a numerical 3D off-lattice reconstruction procedure to a simulation box originally containing silicon and oxygen atoms of a non-porous silica solid. In order to reduce the computational cost, we have applied a homothetic decrease of the simulation box dimensions which preserves the morphology and the topology of the pore network (the average pore dimension is then around 30 Å). The surface chemistry is obtained in a realistic fashion by saturating all dangling bonds with hydrogen atoms. Small angle scattering spectra calculated on different numerical samples have evidenced a departure from Porod's law due to surface roughness. The simulated isotherms calculated on such disordered connected porous networks, show the capillary condensation phenomenon. The shape of the adsorption curves differs from that obtained for simple pore geometries. The analysis of the adsorbed quantity distribution indicates partial molecular-film formation depending on the local surface curvature and roughness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008993328699
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The Adsorption of CHClF2 on NaY5.6 Zeolite (2000)
    Springer
    Adsorption 6 (2000), S. 259-267 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; zeolite ; chlorodifluoromethane ; adsorption structure ; H and F NMR ; chemicalshift ; relaxation time ; adsorbate mobility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The adsorption of CHClF2 on NaY5.6 zeolite has been studied by measuring the H and F NMR of the adsorbed CHClF2, focusing in particular on the measurements of the chemical shift and longitudinal relaxation time, as well as the adsorption isotherm measurements. It is possible to determine the coordination structure of the CHClF2 adsorbed on NaY5.6 zeolite by measuring the adsorption amount dependence of the chemical shift. In addition, the motional activity of the adsorbed molecules in the super cage of the zeolite is discussed on the basis of observed longitudinal relaxation times for various adsorption amounts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008997529608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Adsorption Characteristics in Zeolite Nano-Pore Evaluated by use of Nitrogen Monoxide as a Probe Adsorbate (2000)
    Springer
    Adsorption 6 (2000), S. 251-257 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; EPR ; mordenite ; MOR ; NO ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption isotherms of nitrogen monoxide (NO) and in situ EPR spectra of adsorbed NO on mordenite zeolites (MOR) of different cation types (HM, NaM and CaM) are measured at different temperatures to elucidate the effect of the strong adsorption promoted by the enhancement of potential field in micropore of MOR (micropore filling) as well as the electrostatic interaction in MOR on NO adsorption. The NO molecules adsorb irreversibly and fill up the micropore of MOR at 201 K, above the critical temperature of NO, regardless of the kind of cation species. The NO adsorption takes place even at 273 K. In the adsorption at 273 K, the strength of electrostatic field formed by cation sites affects the adsorptivity and the order of saturation amount of adsorption (V s) corresponds to that of the electrostatic field strength. EPR results show that NO molecules strongly interact with cation sites in MOR and disproponation reaction of NO take place on CaM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008945412770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the interaction of a fungal endoglucanase from Humicola insolens with cotton fibres (1997)
    Springer
    Cellulose 4 (1997), S. 7-20 
    Details
    ISSN: 1572-882X
    Keywords: cellulase ; cottonfibres ; electron microscopy ; biopolishing ; adsorption ; colloidalgold labeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Because cellulases are finding more applications in the textile and detergent industries, their effect on cotton fibres must be evaluated. For this purpose, the action of a recombinant cellulase, endoglucanase V from the fungus Humicola insolens, has been followed by scanning electron microscopy (SEM) in classical longitudinal views as well as in cross-sections of cotton fibres. The experiments were conducted at large enzyme dilution typical of conditions where cellulases are used for biopolishing, i.e. for the removal of defects created by mechanical abrasion. Endoglucanase V appears to restrict its action to the hydrolysis of the loose fibrils created at the surface of the fibres and no indication of extensive enzyme penetration and damage to the interior of the fibres could be detected by SEM. The adsorption sites for endoglucanase V on cotton fibres were examined by transmission electron microscopy (TEM) on ultrathin cross-sections after immuno-gold labeling of the enzyme. This approach showed that the enzymes did not penetrate the fibres but remained at their surface. The use of an immuno-gold labeled cellulase provides a new way to probe the surface features of cotton fibres
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018454900127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Sorption Equilibria and Kinetics of Hydrocarbons onto Activated Carbon Samples Having Different Micropore Size Distributions (1999)
    Springer
    Adsorption 5 (1999), S. 25-37 
    Details
    ISSN: 1572-8757
    Keywords: micropore size distribution ; activated carbon ; adsorption ; desorption ; equilibrium ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper deals with the prediction of adsorption equilibrium and kinetics of hydrocarbons onto activated carbon samples having different micropore size distribution (MPSD). The microporous structure of activated carbon is characterised by the distribution of slit-shaped micropores, which is assumed to be the sole source of surface heterogeneity. The interaction between adsorbate molecule and pore walls is described by the Lennard-Jones potential theory. Different adsorbates have access to different pore size range of activated carbon due to the size exclusion, a phenomenon could have a significant influence on both multicomponent equilibria and kinetics. Activated carbons with three different MPSDs are studied with ethane and propane as the two model adsorbates. The Heterogeneous Macropore Surface Diffusion model (HMSD) is employed to simulate adsorption kinetics. The simulation results show that the MPSD is an important factor affecting both the multicomponent equilibria and kinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026481704926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Equilibrium Adsorption of Light Alkanes in Silicalite-1 by the Inertial Microbalance Technique (2000)
    Springer
    Adsorption 6 (2000), S. 159-167 
    Details
    ISSN: 1572-8757
    Keywords: silicalite-1 ; adsorption ; TEOM ; alkanes ; isosteric heat ; adsorption entropy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The equilibrium adsorption of the light alkanes methane, ethane, propane, n-butane, and i-butane in silicalite-1 has been investigated using the TEOM technique. Either a conventional or a dual-site Langmuir isotherm appropriately describes the equilibrium data. Good agreement with the literature data determined by other techniques indicates the TEOM is a reliable technique. The adsorption of i-butane in silicalite-1 reveals the discrete preferential molecular siting, implying a discrete-dual-structural heterogeneity for light alkanes in silicalite-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008969518892
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Thermodynamics of Copper Adsorption-Desorption by Ca-Kaolinite (2000)
    Springer
    Adsorption 6 (2000), S. 325-335 
    Details
    ISSN: 1572-8757
    Keywords: copper ; ca-koalinite ; adsorption ; desorption ; thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The temperature effect on Cu adsorption and desorption on kaolinite has been investigated at four temperatures (8°C, 25°C, 30°C and 40°C). The clay sample was saturated with Ca. Copper was sorbed from solutions containing eleven Cu concentrations between 0.0010 and 0.0211 M, equilibrated for 2 days. Cu adsorption decreased, but desorption increased with increasing temperature, indicating that adsorption is an exothermic process while desorption is endothermic. These conclusions are confirmed by the values of ΔH 0 estimated for adsorption and desorption. The initial copper concentration is a significant factor influencing mainly the adsorption process, which is spontaneous (ΔG 0 〈 0) only for low initial Cu concentrations. The desorption process is spontaneous for all Cu concentrations. ΔS 0 values have also been calculated. Experimental adsorption data were successfully fitted to the Freundlich isotherm and to the Gouy-Chapman model in order to express the process quantitatively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026513032260
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Static and Kinetic Studies on the Adsorption Behavior of Sulfadiazene (2000)
    Springer
    Adsorption 6 (2000), S. 349-357 
    Details
    ISSN: 1572-8757
    Keywords: sulfadiazene ; adsorption ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract To investigate the nature of interactive forces between sulfadiazene molecules and alumina surface the experiments were performed for the adsorption of sulfadiazene (SD) from its aqueous sulution onto the alumina surfaces at 25 ± 0.2°C and the influence of factors such as increasing concentration of SD (4.0–20.0 × 10−3 mol cm−3), the time required for adsorption equilibrium, pH (2.0–12.0) and temperature (5–45°C) of the adsorption medium, the presence of ions like Cl−, SO2− 4 and PO3− 4 (0.01–0.30 M) and organic solvents (5% v/v) were observed on the course of adsorption of SD. Various adsorption and kinetic parameters such as adsorption coefficient, the rate constants for adsorption and desorption were also evaluated. The results of the above cited studies facilitated to formulate the mechanisms of interaction between SD and alumina surfaces. From application view point the present work may be a potential tool for an effective chromatographic separation of sulfa drugs from industrial effluents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026517117239
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Adsorption of a Trichoderma reesei endoglucanase and cellobiohydrolase onto bleached Kraft fibres (1997)
    Springer
    Cellulose 4 (1997), S. 255-268 
    Details
    ISSN: 1572-882X
    Keywords: biotechnology ; cellulase ; endoglucanase ; cellobiohydrolase ; adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Cellulases can be used to modify pulp fibres. For the development of biotechnical applications, a better understanding of the adsorption of cellulases onto commercial wood fibres is needed. In this work, the adsorption behaviour of purified CBH I and EG II on bleached Kraft fibres was investigated. Three variables were studied with respect to their effect on adsorption: fibre type (hardwood or softwood), fibre history (never-dried or once-dried), and ionic strength. The results showed that fibre history had the largest influence on the extent of adsorption of each enzyme. The effect of ionic strength was shown to be dependent on the enzyme and fibre type. At high ionic strength, CBH I exhibited a higher affinity for both once-dried and never-dried fibres at low enzyme concentrations; however, salt was shown to decrease the extent of adsorption at higher enzyme dosages. In contrast, salt increased the maximum adsorption of EG II, most notably on the once-dried hardwood fibres. Fibre type was also shown to affect adsorption behaviour. CBH I had a higher affinity for softwood fibres than for hardwood fibres at low enzyme concentrations. The maximum adsorption of EG II onto once-dried softwood fibres increased by 80% compared to the once-dried hardwood fibres. Interestingly, this did not correlate to in creased fibre hydrolysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018444008305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    A Study of Adsorption of Water Vapour on Wool under Static and Dynamic Conditions (1998)
    Springer
    Adsorption 4 (1998), S. 63-73 
    Details
    ISSN: 1572-8757
    Keywords: wool ; water vapour ; adsorption ; diffusion ; column dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption of water vapour on wool provides not only textile comfort, but also convenience in transportation due to increase in its bulk density. The adsorption and desorption isotherms of water vapour for wool were determined by both volumetric technique using a Coulter Omnisorp 100CX instrument and gravimetric method employing a Cahn 2000 electronic microbalance. Adsorption isotherm fitting to B.E.T. model and hysteresis on desorption was observed. The average effective diffusion coefficient of water in wool was found to be 8.4 × 10-14 m2s-1 at 25°C from gravimetric data. The effects of packing height and air velocity on the breakthrough curves were also investigated in the wool packed columns. For pseudo first order model, k values changing between 0.33 × 10-6 − 69 × 10-6 s-1 was obtained for 2.2–6.4 cm s-1 air velocity and 0.05–0.20 m packing height ranges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008839404382
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Effects of Surface Oxygen of Activated Carbon on Alkaloid Adsorption: A Molecular Dynamics Simulation Study (1999)
    Springer
    Adsorption 5 (1999), S. 97-108 
    Details
    ISSN: 1572-8757
    Keywords: adsorption ; molecular simulation ; activated carbon ; surface oxygen ; alkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The influence of the density and the type of surface oxygen on the adsorption of berberine alkaloid onto activated carbon was investigated using the molecular dynamics simulation method in vacuum. The carbon surface consisted of a basal plane of graphite and surface oxygen groups which were bonded on the graphite plane in a regular square array with various densities. Two types of surface oxygen groups, =O and —OH, were employed. The simulation results showed that the berberine alkaloids were favorable to be adsorbed on the negative charged carbon surfaces. It was indicated that the vdw attraction of the carbon surface to the alkaloid molecule dominates the adsorption only at the lower surface density of oxygen. It is also indicated that a good adsorptive selectivity for a certain berberine alkaloid can be obtained by controlling the density of surface oxygen. The adsorption simulation of berberine alkaloids onto activated carbon in the presence of water was also carried out by using a dome-shape molecular model for presenting the alkaloid/water/carbon system. It was found that the adsorption of berberine alkaloids on the activated carbon which has a higher density of surface oxygen was strongly inhibited by the presence of water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026479130851
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Pure and Binary Gas Adsorption Equilibria and Kinetics of Methane and Nitrogen on 4A Zeolite by Isotope Exchange Technique (1999)
    Springer
    Adsorption 5 (1999), S. 145-158 
    Details
    ISSN: 1572-8757
    Keywords: kinetics ; isotope-exchange ; nitrogen ; adsorption ; methane ; zeolite ; equilibria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The Isotope Exchange Technique (IET) was used to simultaneously measure pure and binary gas adsorption equilibria and kinetics (self-diffusivities) of CH4 and N2 on pelletized 4A zeolite. The experiment was carried out isothermally without disturbing the adsorbed phase. CH4 was selectively adsorbed over N2 by the zeolite because of its higher polarizability. The multi-site Langmuir model described the pure gas and binary adsorption equilibria fairly well at three different temperatures. The selectivity of adsorption of CH4 over N2 increased with increasing pressure at constant gas phase composition and temperature. This curious behavior was caused by the differences in the sizes of the adsorbates. The diffusion of CH4 and N2 into the zeolite was an activated process and the Fickian diffusion model described the uptake of both pure gases and their mixtures. The self-diffusivity of N2 was an order of magnitude larger than that for CH4. The pure gas self-diffusivities for both components were constants over a large range of surface coverages (0 〈 θ 〈 0.5). The self-diffusivities of CH4 and N2 from their binary mixtures were not affected by the presence of each other, compared to their pure gas self-diffusivities at identical surface coverages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008917308002
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Impedance Spectroscopic Measurements of Pure Gas Adsorption Equilibria on Zeolites (1999)
    Springer
    Adsorption 5 (1999), S. 159-167 
    Details
    ISSN: 1572-8757
    Keywords: impedance spectroscopy ; uptake curve ; adsorption ; polarization of adsorbate ; dielectric properties of adsorbed phases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Physisorption equilibria of gases on inert porous solids like activated carbon or molecular sieves can be characterized by measuring the (frequency dependent) capacitance of a capacitor filled with a sample adsorbent. This quantity strongly depends not only on the physico-chemical structure of the empty adsorbent in vacuum, but also on the permanent or induced dipole moments of the molecules adsorbed and of the fluid phase. Consequently, it should be possible to determine the excess mass being adsorbed on the internal surface of a highly porous solid by measurements of the dielectric constant. The aim of this work is to show for various pure gases and adsorbents that the change of the capacitance of an adsorption system depends on the adsorbed mass. Therefore, this effect can be used to characterize porous solids and their adsorbates and, for example, to check the state or the quality of industrial adsorbents during a process on site if calibration measurements have been taken (Staudt et al., 1994, 1998).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008969308910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Liquid Phase Separation of Polar Hydrocarbons from Light Aromatics Using Zeolites (1999)
    Springer
    Adsorption 5 (1999), S. 399-407 
    Details
    ISSN: 1572-8757
    Keywords: zeolites ; polar compounds ; adsorption ; adsorption isotherms ; equilibrium ; liquid phase ; breakthrough curves ; acetonitrile ; acrylonitrile ; dioxane ; ZSM-5 ; MCM-22 ; Na-X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The liquid phase removal of low concentrations of polar compounds (acetonitrile, acrylonitrile and dioxane) from toluene by adsorption on zeolites reveals very high selectivity factors. Kinetic selectivity factors as high as 16,100 are observed. The selection of the zeolites (MFI, MWW and FAU type) allowed the study of the effects of varying aluminum content, the presence and absence of acidic centers and varying pore volumes. To assess the relative effectiveness of each adsorbent, both equilibrium and continuous flow, pseudo equilibrium, breakthrough experiments were conducted. The continuous flow experiments were carried out at 25 and 75°C. The zeolites H-ZSM-5, H-MCM-22 and Na-X are highly effective in removing the polar compounds from toluene to a concentration level down to less than 20 ppm (detection limit). The results obtained with the equilibrium batch experiments are confirmed by the continuous flow breakthrough experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008916917943
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Cellulases and their interaction with cellulose (1994)
    Springer
    Cellulose 1 (1994), S. 169-196 
    Details
    ISSN: 1572-882X
    Keywords: cellulases ; hydrolysis ; adsorption ; multidomain structure ; synergy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Most effective cellulolytic enzymes are made of at least two constitutive domains, a catalytic domain and a non-catalytic cellulose-binding domain linked by a flexible peptide. There are several families of catalytic domains and of cellulose-binding domains resulting in a large number of their possible combinations. Removal of the cellulose-binding domain drastically reduces the binding capacity of cellulases to insoluble cellulose while the catalytic efficiency on soluble substrates is usually maintained. Isolated cellulose-binding domains bear most of the binding properties of cellulases (quasi-irreversibility and dispersive effect) but do not hydrolyse cellulose. The multiple types of synergy that cellulases display when acting in combination on cellulose appear to result from their different activities and selectivity, from the substrate microheterogeneity, and sometimes from both.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Effect of in situ ethanol removal on fermentation of d-xylose by Pachysolen tannophilus
    Amsterdam : Elsevier
    Enzyme and Microbial Technology 7 (1985), S. 217-219 
    Details
    ISSN: 0141-0229
    Keywords: Ethanol ; adsorption ; fermentation ; inhibition ; silicalite ; xylose
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0141-0229(85)80005-3
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Characterization of a β-galactosidase fusion protein containing the starch-binding domain of Aspergillus glucoamylase
    Amsterdam : Elsevier
    Enzyme and Microbial Technology 16 (1994), S. 18-23 
    Details
    ISSN: 0141-0229
    Keywords: Granular starch ; adsorption ; elution ; fusion protein ; starch-binding domain ; β-galactosidase
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0141-0229(94)90104-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Near-quantitative production of fatty acid alkyl esters by lipase-catalyzed alcoholysis of fats and oils with adsorption of glycerol by silica gel
    Amsterdam : Elsevier
    Enzyme and Microbial Technology 16 (1994), S. 478-484 
    Details
    ISSN: 0141-0229
    Keywords: Alcoholysis ; adsorption ; interesterification ; lipase ; operational stability ; silica gel
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0141-0229(94)90017-5
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Adsorption of metal ions by Rhizopus arrhizus biomass: Characterization studies
    Amsterdam : Elsevier
    Enzyme and Microbial Technology 16 (1994), S. 671-675 
    Details
    ISSN: 0141-0229
    Keywords: Rhizopus arrhizus ; adsorption ; isotherms, hard and soft metals ; metal ions
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0141-0229(94)90088-4
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Adsorption kinetics of exoglucanase in combination with endoglucanase from Trichoderma viride on microcrystalline cellulose and its influence on synergistic degradation
    Amsterdam : Elsevier
    Enzyme and Microbial Technology 16 (1994), S. 649-658 
    Details
    ISSN: 0141-0229
    Keywords: Cellulose ; adsorption ; cellulase ; synergism ; thermodynamics
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0141-0229(94)90085-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Lectin-biotin assay for slime present inin situ biofilm produced byStaphylococcus epidermidis using transmission electron microscopy (TEM) (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 156-161 
    Details
    ISSN: 1476-5535
    Keywords: S. epidermidis ; biofilm ; slime ; lectin marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A lectin-biotin assay was developed for use in the specific detection of slime produced byStaphylococcus epidermidis RP62A and M187sp11 grown in a chemically defined medium. Mature biofilm was formed on polyvinylchloride (PVC) disks using a combined chemostat-modified Robbins device (MRD) model system. Specimens fixedin situ were: 1) stained with ruthenium red; 2) reacted overnight with biotin-labeled lectins (WGA, succinyl-WGA, Con A, or APA) followed by treatment with gold-labeled extravidin; or 3) reacted with antibodies againstS. epidermidis RP62A capsular polysaccharide/adhesin (PS/A) using an immunogold procedure. WGA and succinyl-WGA (S-WGA), which specifically bindN-acetylglucosamine, were shown by TEM to react only with slime, both cell-associated and exocellular. In contrast, Con A, APA and anti-PS/A reacted with the bacterial cell surface but did not react with slime. These results indicate the usefulness of WGA lectin as a specific marker for detection of the presence and distribution of slime matrix material inS. epidermidis biofilm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569820
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Continuous ethanol production byZymomonas mobilis andSaccharomyces cerevisiae in biofilm reactors (1996)
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 249-256 
    Details
    ISSN: 1476-5535
    Keywords: ethanol ; biofilm ; plastic composite-supports ; Zymomonas ; Saccharomyces
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Continuous ethanol fermentations were performed in duplicate for 60 days withZymomonas mobilis ATCC 331821 orSaccharomyces cerevisiae ATCC 24859 in packed-bed reactors with polypropylene or plastic composite-supports. The plastic composite-supports used contained polypropylene (75%) with ground soybean-hulls (20%) and zein (5%) forZ. mobilis, or with ground soybean-hulls (20%) and soybean flour (5%) forS. cerevisiae. Maximum ethanol productivities of 536 gL−1 h−1 (39% yield) and 499 gL−1 h−1 (37% yield) were obtained withZ. mobilis on polypropylene and plastic composite-supports of soybean hull-zein, respectively. ForZ. mobilis, and optimal yield of 50% was observed at a 1.92h−1 dilution rate for soybean hull-zein plastic composite-supports with a productivity of 96gL−1h−1, whereas with polypropylene-supports the yield was 32% and the productivity was 60gL−1h−1. With aS. cerevisiae fermentation, the ethanol production was less, with a maximum productivity of 76gL−1h−1 on the plastic composite-support at a 2.88h−1 dilution rate with a 45% yield. Polypropylene-support bioreactors were discontinued due to reactor plugging by the cell mass accumulation. Support shape (3-mm chips) was responsible for bioreactor plugging due to extensive biofilm development on the plastic composite-supports. With suspensionculture continuous fermentations in continuously-stirred benchtop fermentors, maximum productivities of 5gL−1h−1 were obtained with a yield of 24 and 26% withS. cerevisiae andZ. mobilis, respectively. Cell washout in suspensionculture continuous fermentations was observed at a 1.0h−1 dilution rate. Therefore, for continuous ethanol fermentations, biofilm reactors out-performed suspension-culture reactors, with 15 to 100-fold higher productivities (gL−1h−1) and with higher percentage yields forS. cerevisiae andZ. mobilis, respectively. Further research is needed with these novel supports to evaluate different support shapes and medium compositions that will permit medium flow, stimulate biofilm formation, reduce fermentation costs, and produce maximum yields and productivities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01570029
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Diversity in surface colonization behavior in marine bacteria (1996)
    Springer
    Journal of industrial microbiology and biotechnology 17 (1996), S. 228-234 
    Details
    ISSN: 1476-5535
    Keywords: colonization ; biofilm ; diversity ; proximal vertical packing ; cell-cell interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Using laminar flow chambers and time-lapse video imaging, colonization of surfaces by four marine bacteria revealed a diverse range of morphological characteristics and cell-cell interactions. The strain SW5 formed a compact, multilayered single- and double-cell biofilm on hydrophobic surfaces but developed long multicellular chains on hydrophilic surfaces. The morphologically similar SW8 showed unusual proximal vertical packing of cells on both substrata.Vibrio sp strain S14 exhibited cyclical colonization-detachment events on both substrata.Pseudomonas sp strain S9 initially displayed reversible and then irreversible adhesion apparently triggered by a cell density phenomenon that led to the development of regular microcolonies on both substrata with individual cells translocating between the colonies. The length of time bacteria were exposed to and their density at a surface influenced behavioral traits, with diverse and distinctive species-specific behavioral events.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01574697
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Interspecies bacterial interactions in biofilms (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 257-262 
    Details
    ISSN: 1476-5535
    Keywords: bacteria ; interaction ; biofilm ; mixed-species ; community
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Interactions among bacterial populations can have a profound influence on the structure and physiology of microbial communities. Interspecies microbial interactions begin to influence a biofilm during the initial stages of formation, bacterial attachment and surface colonization, and continue to influence the structure and physiology of the biofilm as it develops. Although the majority of research on bacterial interactions has utilized planktonic communities, the characteristics of biofilm growth (cell positions that are relatively stable and local areas of hindered diffusion) suggest that interspecies interactions may be more significant in biofilms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569978
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Structure, function and immunochemistry of bacterial exopolysaccharides (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 339-346 
    Details
    ISSN: 1476-5535
    Keywords: polysaccharides ; bacterial capsule ; biofilm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract There has been much written on bacterial exopolysaccharides (EPS) and their role in virulence. Less has been published regarding EPS in free living species. This review focuses on that subject, emphasizing their functions in the environment and the use of antibody probes to study them.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569989
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    A dual fluorescence technique for visualization ofStaphylococcus epidermidis biofilm using scanning confocal laser microscopy (1996)
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 48-56 
    Details
    ISSN: 1476-5535
    Keywords: Staphylococcus epidermidis ; biofilm ; laser scanning confocal microscopy ; slime ; lectin marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A new dual fluorescence technique is described which, when combined with scanning confocal laser microscopy (SCLM), can be used to visualize the components of biofilm produced byStaphylococcus epidermidis. Chemostat cultures of RP62A (a well-characterized slime-producing strain ofS. epidermidis) were used to produce mature biofilm on polyvinylcholoride (PVC) disks immobilized in a modified Robbins device using a ‘seed’ and ‘feed’ model system. Serial horizontal and vertical optical thin sections, as well as three-dimensional computer reconstructions, were obtained onin situ biofilm using the dual fluorescence procedure. Bacteria were visualized by green autofluorescence excited at 488 nm with an Argon laser. Cell-associated and exocellular matrix material (slime) was visualized by red fluorescence excited at 568 nm with a Krypton laser after interaction of the biofilm with Texas Red-labeled wheat germ agglutinin which is a slime-specific lectin marker. Structural analysis revealed that the cocci grew in slime-embedded cell clusters forming distinct conical-shaped microcolonies. Interspersed open channels served to connect the bulk liquid with the deepest layers of the mature, hydrated biofilm which increased overall surface area and likely facilitated the exchange of nutrients and waste products throughout the biofilm. The combined dual fluorescence technique and SCLM is potentially useful as a specific noninvasive tool for studying the effect of antimicrobial agents on the process of biofilm formation and for the characterization of the architecture ofS. epidermidis biofilm formedin vivo andin vitro on medical grade virgin or modified inert polymer surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569921
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Variation in sessile microflora during biofilm formation on AISI-304 stainless steel coupons (1996)
    Springer
    Journal of industrial microbiology and biotechnology 17 (1996), S. 6-10 
    Details
    ISSN: 1476-5535
    Keywords: biofilm ; cooling water ; microbiologically influenced corrosion ; microbial fouling ; stainless steel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Coupons of stainless steel type AISI-304 were exposed to the industrial cooling system of a petrochemical plant fed by seawater from the Guanabara Bay, Rio de Janeiro, Brazil, in order to study thein situ formation of biofilms. Bacteria, microalgae and fungi were detected on the coupons as soon as 48 h after exposure. Their respective numbers were determined at times 48, 96 and 192 h and over the following 8 weeks. Aerobic, anaerobic and sulfate-reducing bacteria were quantified according to the technique of the most probable number, and fungi by the pour plate technique. The number of microorganisms present in the forming biofilm varied over the experimental period, reaching maximal levels of 14×1011 cells cm−2, 30×1013 cells cm−2, 38×1011 cells cm−2 and 63×105 cells cm−2, respectively, for aerobic bacteria, anaerobic bacteria, sulfate-reducing bacteria and fungi, and the dynamics of this variation depended on the group of microorganisms.Bacillus sp,Escherichia coli, Serratia sp andPseudomonas putrefaciens were identified among the aerobic bacteria isolated. Additionally, microalgae and bacteria of the genusGallionella were also detected. Nonetheless, no evidence of corrosion was found on the stainless steel type AISI-304 coupons over the experimental period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01570140
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Dental plaque as a biofilm (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 169-175 
    Details
    ISSN: 1476-5535
    Keywords: dental plaque ; biofilm ; adhesion ; co-aggregation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Dental plaque is the diverse microbial community found on the tooth surface embedded in a matrix of polymers of bacterial and salivary origin. Once a tooth surface is cleaned, a conditioning film of proteins and glycoproteins is adsorbed rapidly to the tooth surface. Plaque formation involves the interaction between early bacterial colonisers and this film (the acquired enamel pellicle). To facilitate colonisation of the tooth surface, some receptors on salivary molecules are only exposed to bacteria once the molecule is adsorbed to a surface. Subsequently, secondary colonisers adhere to the already attached early colonisers (co-aggregation) through specific molecular interactions. These can involve protein-protein or carbohydrate-protein (lectin) interactions, and this process contributes to determining the pattern of bacterial succession. As the biofilm develops, gradients in biologically significant factors develop, and these permit the co-existence of species that would be incompatible with each other in a homogeneous environment. Dental plaque develops naturally, but it is also associated with two of the most prevalent diseases affecting industrialised societies (caries and periodontal diseases). Future strategies to control dental plaque will be targeted to interfering with the formation, structure and pattern of development of this biofilm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569822
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Continuous nondestructive monitoring of microbial biofilms: A review of analytical techniques (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 263-276 
    Details
    ISSN: 1476-5535
    Keywords: biofilm ; on-line monitoring ; nondestructive monitoring ; microscopy ; Fourier-transform infrared spectrometry ; bioluminescence ; microelectrode ; quartz crystal microbalance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A fundamental requirement for the understanding and control of biofilms is the continuous nondestructive monitoring of biofilm processes. This paper reviews research analytical techniques that monitor biofilm processes in a continuous nondestructive manner and that could also be modified for industrial applications. To be considered ‘continuous’ and ‘nondestructive’ for the purpose of this review a technique must: (a) function in an aqueous system; (b) not require sample removal; (c) minimize signal from organisms or contaminants in the bulk phase; and (d) provide real-time data. Various microscopic, spectrochemical, electrochemical, and piezoelectrical analysis methods fulfill these criteria. These techniques monitor the formation of biofilms, the physiology of the microorganisms within biofilms, and/or the interaction of the biofilms with their environment. It is hoped that this review will stimulate development and use of biofilm monitoring techniques in industrial and environmental settings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569979
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Physical and chemical characterization of the polysaccharide capsule of the marine bacterium,Hyphomonas strain MHS-3 (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 347-351 
    Details
    ISSN: 1476-5535
    Keywords: polysaccharides ; bacterial capsule ; adhesion ; biofilm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Hyphomonas MHS-3 is a biphasic, marine bacterium that synthesizes an exopolysaccharide (EPS) capsule, which has a role in attaching the adherent, prosthecate developmental stages to solid substrata. To correlate structure with function, we characterized this integral EPS. It has a relatively homogeneous molecular weight of approximately 60000 daltons, is acidic, and putatively contains large concentrations ofN-acetylgalactosamine (GalNAc). The theoretical identity of the anionic component of the polymer, and the similarities betweenHyphomonas MHS-3 EPS and other adhesive marine/aquatic bacterial EPS are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569990
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Prevention of biofilm formation by polymer modification (1995)
    Springer
    Journal of industrial microbiology and biotechnology 15 (1995), S. 391-396 
    Details
    ISSN: 1476-5535
    Keywords: biofilm ; prevention ; polymer modification ; glow discharge treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Bacterial biofilm formation on synthetic polymers plays an important role in industry and in modern medicine, leading, for example, to difficult-to-treat infections caused by colonized foreign bodies. Prevention of biofilm formation is a necessary step in the successful prophylaxis of such infections. One approach is to inhibit bacterial adherence by polymer surface modification. We have investigated polymer modification by glow discharge treatment in order to study the influence of the modified surface on bacterial adherence. Surface roughness, surface charge density and contact angles of the modified polymers were determined and related to the adherence ofStaphylococcus epidermidis KH6. Although no influence of surface roughness and charge density on bacterial adherence was noticed, a correlation between the free enthalpy of adhesion (estimated from contact angle measurements) and adherence was observed. There seems to exist a certain minimum bacterial adherence, independent of the nature of the polymer surface. Modified polymers with negative surface charge allow for bacterial adherence close to the adherence minimum. These polymers could be improved further by the ionic bonding of silver ions to the surface. Such antimicrobial polymers are able to prevent bacterial colonization, which is a prerequisite for biofilm formation. It is suggested that modification of polymers and subsequent surface coupling of antimicrobials might be an effective approach for the prevention of bacterial biofilm formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569996
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Evaluation of plastic composite-supports for enhanced ethanol production in biofilm reactors (1996)
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 241-248 
    Details
    ISSN: 1476-5535
    Keywords: ethanol ; biofilm ; Zymomonas ; Saccharomyces ; Streptomyces ; plastic composite-supports
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Biofilms are a natural form of cell immobilization that result from microbial attachment to solid supports. Biofilm reactors with polypropylene composite-supports containing up to 25% (w/w) of various agricultural materials (corn hulls, cellulose, oat hulls, soybean hulls or starch) and nutrients (soybean flour or zein) were used for ethanol production. Pure cultures ofZymomonas mobilis, ATCC 31821 orSaccharomyces cerevisiae ATCC 24859 and mixed cultures with either of these ethanol-producing microorganisms and the biofilm-formingStreptomyces viridosporus T7A ATCC 39115 were evaluated. An ethanol productivity of 374g L−1 h−1 (44% yield) was obtained on polypropylene composite-supports of soybean hull-zein-polypropylene by usingZ. mobilis, whereas mixed-culture fermentations withS. viridosporus resulted in ethanol productivity of 147.5 g L−1 h−1 when polypropylene composite-supports of corn starch-soybean flour were used. WithS. cerevisiae, maximum productivity of 40 g L−1 h−1 (47% yield) was obtained on polypropylene composite-supports of soybean hull-soybean flour, whereas mixed-culture fermentation withS. viridosporus resulted in ethanol productivity of 190g L−1 h−1 (35% yield) when polypropylene composite-supports of oat hull-polypropylene were used. The maximum productivities obtained without supports (suspension culture) were 124 g L−1 h−1 and 5 g L−1 h−1 withZ. mobilis andS. cerevisiae, respectively. Therefore, forZ. mobilis andS. cerevisiae, ethanol productivities in biofilm fermentations were three- and eight-fold higher than suspension culture fermentations, respectively. Biofilm formation on the chips was detected by weight change and Gram staining of the support material at the end of the fermentation. The ethanol production rate and concentrations were consistently greater in biofilm reactors than in suspension cultures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01570028
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    A review of experimental measurements of effective diffusive permeabilities and effective diffusion coefficients in biofilms (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 59 (1998), S. 261-272 
    Details
    ISSN: 0006-3592
    Keywords: effective diffusive permeability ; diffusion coefficient ; biofilm ; cell density ; review ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental measurements of effective diffusive permeabilities and effective diffusion coefficients in biofilms are reviewed. Effective diffusive permeabilities, the parameter appropriate to the analysis of reaction-diffusion interactions, depend on solute type and biofilm density. Three categories of solute physical chemistry with distinct diffusive properties were distinguished by the present analysis. In order of descending mean relative effective diffusive permeability (De/Daq) these were inorganic anions or cations (0.56), nonpolar solutes with molecular weights of 44 or less (0.43), and organic solutes of molecular weight greater than 44 (0.29). Effective diffusive permeabilities decrease sharply with increasing biomass volume fraction suggesting a serial resistance model of diffusion in biofilms as proposed by Hinson and Kocher (1996). A conceptual model of biofilm structure is proposed in which each cell is surrounded by a restricted permeability envelope. Effective diffusion coefficients, which are appropriate to the analysis of transient penetration of nonreactive solutes, are generally similar to effective diffusive permeabilities in biofilms of similar composition. In three studies that examine diffusion of very large molecular weight solutes ( 〉 5000) in biofilms, the average ratio of the relative effective diffusion coefficient of the large solute to the relative effective diffusion coefficient of either sucrose or fluorescein was 0.64, 0.61, and 0.36. It is proposed that large solutes are effectively excluded from microbial cells, that small solutes partition into and diffuse within cells, and that ionic solutes are excluded from cells but exhibit increased diffusive permeability (but decreased effective diffusion coefficients) due to sorption to the biofilm matrix. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:261-272, 1998.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 53
    Electronic Resource
    Electronic Resource
    Analysis of protein fouling during ultrafiltration using a two-layer membrane model (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 59 (1998), S. 451-460 
    Details
    ISSN: 0006-3592
    Keywords: protein fouling ; membrane transport ; ultrafiltration ; adsorption ; filtration ; composite membrane ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Protein fouling can significantly alter both the flux and retention characteristics of ultrafiltration membranes. There has, however, been considerable controversy over the nature of this fouling layer. In this study, hydraulic permeability and dextran sieving data were obtained both before and after albumin adsorption and/or filtration using polyethersulfone ultrafiltration membranes. The dextran molecular weight distributions were analyzed by gel permeation chromatography to evaluate the sieving characteristics over a broad range of solute size. Protein fouling caused a significant reduction in the dextran sieving coefficients, with very different effects seen for the diffusive and convective contributions to dextran transport. The changes in dextran sieving coefficients and diffusive permeabilities were analyzed using a two-layer membrane model in which a distinct protein layer is assumed to form on the upstream surface of the membrane. The data suggest that the protein layer formed during filtration was more tightly packed than that formed by simple static adsorption. Hydrodynamic calculations indicated that the pore size of the protein layer remained relatively constant throughout the adsorption or filtration, but the thickness of this layer increased with increasing exposure time. These results provide important insights into the nature of protein fouling during ultrafiltration and its effects on membrane transport. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:451-460, 1998.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 54
    Electronic Resource
    Electronic Resource
    Activity of an isothiazolone biocide against Hormoconis resinae in pure and mixed biofilms (1996)
    Springer
    World journal of microbiology and biotechnology 12 (1996), S. 395-397 
    Details
    ISSN: 1573-0972
    Keywords: Biocide ; biofilm ; Hormoconis ; immunofluorescence ; Kathon FP ; stainless steel ; sulphate-reducing bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Biofilms containing single or mixed cultures of the fungus Hormoconis resinae and anaerobic sulphate-reducing bacteria (SRB) on stainless steel were incubated with an isothiazolone biocide (Kathon FP) at 28°C for 24 h. H. resinae within the biofilm was enumerated by immunofluorescence microscopy using specific antiserum, and SRB were assayed by culture. Fungal numbers in mixed biofilms were considerably reduced in comparison with those in pure biofilms. The biocide was shown to be effective against H. resinae in pure biofilms at 50 and 100 ppm, but in mixed biofilms only at the higher concentration. This concentration also reduced the sessile SRB numbers by 99%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Reaction kinetics in biofilms (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 877-882 
    Details
    ISSN: 0006-3592
    Keywords: microtechnique ; microprobe ; biofilm ; dissolved oxygen concentration ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel in situ microtechnique allows evaluating parameters of diffusion-controlled reactions in biofilms. A microprobe, 15 μm in diameter, was used to simultaneously measure the dissolved oxygen concentration and the optical density at different depths in a submerged biofilm. Based on the results, the biofilm diffusion coefficient for dissolved oxygen, Df the dissolved oxygen flux through the biofilm surface, J02, and the half velocity coefficient, Ks, have been calculated.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260380809
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Prediction of a protein band profile in preparative reversed-phase gradient elution chromatography (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 877-885 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; chromatography ; gradient-elution ; isotherms ; proteins ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The overloaded band profiles of lysozyme in reversedphase preparative chromatography were recorded on a C18 chemically bonded silica column, with acetonitrile/water as the mobile phase. These experiments were carried out under isocratic conditions at 31.6, 31.9, and 32.2% acetonitrile (ACN) for loading factors up to 43% of the column saturation capacity and under linear-solvent-strength gradientelution with gradient slopes of 0.5 and 1% ACN/min, for loading factors up to 11.3%. The adsorption isotherms of lysozyme were measured for the same solvent compositions and found to be accurately accounted for by a bi-Langmuir isotherm model.With the use of a Craig model implementation of the equilibrium-dispersive model of chromatography, the band profiles of lysozyme were calculated. An excellent agreement was observed between these calculated profiles and the experimental profiles recorded at loading factors below 5%. By contrast, band profiles calculated using a Langmuir isotherm failed to describe the experimental bands. At column loadings exceeding 8%, a slight but systematic deviation takes place between calculated and experimental profiles. It is most probably explained by the considerable concentration effect of the gradient, making the band experience phase equilibrium in a concentration range that exceeds largely the one where the isotherm data have been measured.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390810
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Removal of dissolved metals by plant tissue (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 1064-1068 
    Details
    ISSN: 0006-3592
    Keywords: strontium ; adsorption ; plant tissue ; Lycopersicon esculentum ; Nicotiana tobacum ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Various types of microbial biomass have been shown to adsorb metals dissolved in aqueous media. It has now been demonstrated that certain plant tissues are also effective for this type of adsorption process. In particular, tomato and tobacco roots harvested from field-grown plants were shown to adsorb Sr from an aqueous solution of SrCl2. Distribution coefficients in excess of 550 were measured and the adsorption isotherms at 25°C could be fitted to Langmuir-type expressions. The bioadsorbent could be regenerated and metals recovered by either a reduction in the pH to less than 2.0 or by use of a concentrated chloride salt solution.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260391011
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    The cellulose-binding domain (CBDCex) of an exoglucanase from Cellulomonas fimi: Production in Escherichia coli and characterization of the polypeptide (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 401-409 
    Details
    ISSN: 0006-3592
    Keywords: cellulose-binding domain ; cellulase ; cellulose ; adsorption ; affinity chromatography ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The gene fragment encoding the cellulose-binding domain (CBD) of an exoglucanase (Cex) from Cellulomonas fimi was subcloned and expressed in Escherichia coli. Transcription from the lac promoter coupled with translation from a consensus prokaryotic ribosome binding site led to the production of large quantities of CBDCex (up to 25% total soluble cell protein). The polypeptide leaked into the culture supernatant (up to 50 mg · L-1), facilitating one-step purification by affinity chromatography on cellulose. The 11-kDa polypeptide reacted with Cex antiserum. Absence of free thiols indicated that the two Cys residues of CBDCex form a disulfide bridge. It had the same N-terminal amino acid sequence as CBDCex prepared from Cex by proteolysis, plus two additional N-terminal amino acid residues (Ala and Ser) encoded by the Nhel site introduced during plasmid construction. CBDCex bound to a variety of β-1, 4-glycans with different affinities and saturation levels. Adsorption to bacterial microcrystalline cellulose was dependent on the temperature, but not on the pH. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Enhanced recovery of solavetivone from Agrobacterium transformed root cultures of Hyoscyamus muticus using integrated product extraction (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 503-508 
    Details
    ISSN: 0006-3592
    Keywords: root culture ; fungal elicitation ; feedback inhibition ; in situ extraction ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The integrated recovery of solavetivone from fungus elicited “hairy root” cultures of Hyoscyamus muticus is examined using volatile organic solvents and solid-phase adsorbents in an external loop extraction configuration. Hexane and pentane are shown to be toxic when added directly to the culture; however, growth of roots is not inhibited when cultures are exposed to media saturated with these hydrocarbons. Solid-phase neutral adsorbents, XAD-7 and XAD-16, display higher capacity and better solavetivone partitioning capability than the hydrocarbons; however, their selectivity for the sesquiterpene solavetivone is poor in comparison with hexane. In both cases, the integration of product recovery through extraction resulted in a doubling of product formation by alleviating feedback repression. Implications of these results to the recovery of secondary metabolites from plant root cultures are discussed. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420414
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    A statistical analysis of the effect of substrate utilization and shear stress on the kinetics of biofilm detachment (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 728-735 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; shear stress ; substrate loading ; biofilm detachment ; Pseudomonas aeruginosa ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: One of the least understood processes affecting biofilm accumulation is detachment. Detachment is the removal of cells and cell products from an established biofilm and subsequent entrainment in the bulk liquid. The goal of this research was to determine the effects of shear stress and substrate loading rate on the rate of biofilm detachment.Monopopulation Pseudomonas aeruginosa and undefined mixed population biofilms were grown on glucose in a RotoTorque biofilm reactor. Three levels of shear stress and substrate loading rate were used to determine their effects on the rate of detachment. Suspended cell concentrations were monitored to determine detachment rates, while other variables were measured to determine their influence on the detachment rate. Results indicate that detachment rate is directly related to biofilm growth rate and that factors which limit growth rate will also limit detachment rate. No significant influence of shear on detachment rate was observed.A new kinetic expression that incorporates substrate utilization rate, yield, and biofilm thickness was compared to published detachment expressions and gives a better correlation of data obtained both in this research and from previous research projects, for both mono- and mixed-population biofilms. © John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410707
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Sorption and precipitation of metals in activated sludge (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 43 (1994), S. 874-880 
    Details
    ISSN: 0006-3592
    Keywords: sludge ; sorption ; precipitation ; metals ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A conceptual model describing the relative roles of sorption and precipitation processes for metals in solid-solution suspensions is presented. The model performance is demonstrated using experimental data on sorption and precipitation of metals in samples of activated sludge mixed liquor. Based on the experimental results presented here, it appears that, at total metal and mixed liquor suspended solids concentrations and pH values generally encountered in full-scale municipal (or combined municipal/industrial) activated sludge systems, metals are primarily removed by sorption processes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260430906
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Heterogeneity of biofilms in rotating annular reactors: Occurrence, structure, and consequences (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 194-204 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; biofilm reactors ; structure ; heterogeneity ; kinetics ; modeling ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A rotating annular reactor (Roto Torque) was used for qualitative and quantitative studied on biofilm heterogeneity. In contrast to the classic image of biofilms as smooth, homogeneous layers of biomass on a substratum, studies using various pure and mixed cultures consistently revealed more-dimensional structures that resembled dunes and ridges, among others. These heterogeneities were categorized and their underlying causes analyzed. Contrary to expectations, motility of the microorganisms not a decisive factor in determining biofilm homogeneity. Small Variations in substratum geometry homogeneity. Small variations in substratum geometry and flow patterns were clearly reflected in the biofilm pattern. Nonhomogeneous flow and shear patterns in the reactor, together with inadequate mixing resulted in significant, position-dependent differences in surface growth. It was therefore not possible to take representative samples of the attached biomass. Like many other types of reactors, the Roto Torque reactor is valuable for qualitative and morphological biofilm experiments but less suitable for quantitative physiological and kinetics studies using attached microorganisms. © 1994 John Wiley & Sons, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Adsorption of BSA on strongly basic chitosan: Equilibria (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 43 (1994), S. 1087-1093 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; ion exchange ; chitosan ; equilibrium ; BSA ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Equilibrium isotherms for adsorption of bovine serum albumin (BSA) on a new adsorbent, a strongly basic crosslinked chitosan (Chitopearl 2503), which is hard and is not compressed by pressure in a column, have been presented and compared with diethylaminoethyl (DEAE) Sepharose Fast Flow (hard gel). In Chitopearl 2503, when only buffer existed in the BSA solution, the isotherm was not affected by the initial concentration of BSA but it was affected by pH considerably. The isotherm was favorable when pH ≥ pl (≅ 4.8). When NaCl existed in the BSA solution, the amount of BSA absorbed on the resin decreased with increasing concentration of NaCl. When the concentration of NaCl was 200 mol/m3, the resin did not adsorb BSA at all. The equilibrium data were correlated by the Langmuir equation reasonably well. The BSA may be adsorbed mainly by electrostatic attraction between negatively charged BSA and positively charged quanternary ammonium groups at pH 〉 pl and by protonation reaction of the primary ammonium groups by weak acid groups of BSA at pH = pl. These are confirmed by measuring the amount of inorganic ion exchanged for BSA. In DEAE Sepharose Fast Flow, the isotherm was favorable when pH 〉 pl but unfavorable ar pH = pl. The saturation capacity of BSA on Chitopearl 2503 is about 1.3 to 2.2 times larger than that on DEAE Sepharose Fast Flow. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260431112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Solids retention time in spherical biofilms in a biofilm airlift suspension reactor (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 867-879 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; microbeads ; solids retention time ; airlift reactor ; particulates ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fluorescent microparticles were used as tracer beads to measure the dynamics of solids in spherical biofilms in a biofilm airlift suspension reactor. Attachment to, release from, and penetration into the biofilms of the tracer beads were measured. The coverage of the biofilm surface was low and the steady state particle concentration on the surface was dependent on the biofilm surface characteristics. The measured attachment rate constant was identical in both experiments and appeared to be determined by the hydrodynamic conditions in the turbulent reactor. The attachment rate was much faster than the release rate of the tracer beads and, therefore, the solidsretention time in the biofilm particle is not due to a simple reversible adsorption-desorption process. The heterogeneity of the distribution oftracer beads on different sectors on the biofilm surface decreased duringthe attachment period. Due to random detachment processes the heterogeneity of the tracer bead distribution increased during the release periodThe tracer beads quickly penetrated into the biofilm and became distributed throughout the active layer of the biofilm. The observed penetration into biofilms, the nonuniform distribution on the biofilm surface, and the fast uptake and slow release of tracer beads cannot be described by a simple model based on a reversible adsorption-desorption mechanism, nor withexisting biofilm models. These biofilm models, which balance growth and advection assuming a uniform biofilm with a homogeneous surface, are inadequate for the description of the observed solids retention time in biofilms. Therefore, a new concept of biofilm dynamics is proposed, in which formation of cracks and fissures, which are rapidly filled with growing biomass, combined with nonuniform local detachment, explains the observed fast penetration into the biofilm of tracer beads, the long residence time, and the nonuniform distibution of fluorescent microparticles. © 1994 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440802
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Membrane bioreactor with a porous hydrophobic membrane as a gas-liquid contactor for waste gas treatment (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 107-115 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; waste gas treatment ; hydrophobic microporous membrane ; mass transfer ; propene ; Xanthobacter ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel type of bioreactor for waste gas treatment has been designed. The reactor contains a microporous hydrophobic membrane to create a large interface between the waste gas and the aqueous phase. To test the new reactor, propene was chosen because of its high air/water partition coefficient, which causes a low water concentration and hampers its removal from air. Propene transfer from air to a suspension of propene-utilizing Xanthobacter Py2 cells in the membrane bioreactor proved to be controlled by mass transfer in the liquid phase. The resistance of the membrane was negligible. Simulated propene transfer rates agreed well with the experimental data. A stable biofilm of Xanthobacter Py2 developed on the membrane during prolonged operation. The propene flux into the biofilm was 1 × 10-6 mol m-2 s-1 at a propene concentration of 9.3 × 10-2 mol m-3 in the gas phase. © 1995 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Equilibria for the adsorption of antibiotics onto neutral polymeric sorbents: Experimental and modeling studies (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 47 (1995), S. 215-226 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; penicillin ; tetracycline ; cephalosporin ; polymeric sorbents ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The objective of this work was to study the equilibria for adsorption of three antibiotics (penicillin V, tetracycline, and cephalosporin C) from water onto commercially available neutral polymeric sorbents. The pH was observed to be an important factor in adsorption as our results suggest that the neutral forms of penicillin V and cephalosporin C are preferentially adsorbed onto the neutral sorbents. Also, sorbent surface chemistry was observed to be important for adsorption, as the antibiotics adsorbed more favorably (both in terms of affinities and enthalpies) onto the aromatic sorbent as compared to the aliphatic ester sorbent. In addition to these thermodynamic measurements, molecular modeling studies and Monte Carlo simulations suggest that adsorption onto aromatic sorbents may involve specific interactions between the planar regions of the antibiotic molecules and the phenyl rings of the aromatic sorbent. The interaction energies predicted from Monte Carlo simulations were observed to provide qualitative agreement with experimentally determined adsorption affinities. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260470213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Quantitative analysis of biofilm thickness variability (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 503-510 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; thickness ; heterogeneity ; roughness ; microscopy ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The thickness variability of biofilms of Pseudomonas aeruginosa, Klebsiella pneumoniae, and the binary population combination of these two species was quantified. The experimental method involved cryoembedding biofilms with a commercial tissue embedding agent, sectioning, and applying image analysis to construct thickness profiles along linear transects (up to 1 cm in length) across the substratum. Biofilms embedded and sectioned by this method were locally as thin as a single cell attached to the surface (〈5 μm) and as thick as 1000 μm. Week-old biofilms of three different species compositions displayed distinct structural features as indicated by their mean thicknesses and by a roughness coefficient. Monopopulation biofilms of P. aeruginosa (29 μm mean thickness) or K. pneumoniae (100 μm mean thickness) were thinner than the binary population biofilm (400 μm mean thickness). A roughness coefficient developed in this investigation corroborated the qualitative visual characterization of P. aeruginosa biofilms as relatively uniformly thick (mean roughness coefficient 0.15), K. pneumoniae biofilms as patchy (mean roughness coefficient 1.14), and the binary population biofilm as intermediate (mean roughness coefficient 0.26). Whereas P. aeruginosa and binary population biofilms covered the substratum completely, significant areas of essentially bare substratum were apparent in K. pneumoniae biofilms. The patchiness of K. pneumoniae biofilms may be due to the fact that this organism is nonmotile. A spatial correlation analysis of the thickness data indicated that thickness measurements were still correlated even when separated by distances that exceeded the mean biofilm thickness. Cell aggregates, some of them hundreds of microns in size, were observed in the effluent of K. pneumoniae and binary population biofilm reactors. Measurements of thickness variability and other observations reported in this article provide a quantitative basis for analysis of microscale structural heterogeneity of biofilms. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Bioleaching of zinc sulfide concentrate by Thiobacillus ferrooxidans (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 66-74 
    Details
    ISSN: 0006-3592
    Keywords: bioleaching ; adsorption ; growth kinetics ; Thiobacillus ferrooxidans ; zinc sulfide ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of the bioleaching of ZnS concentrate by Thiobacillus ferrooxidans was studied in a well-mixed batch reactor. Experimental studies were made at 30°C and pH 2.2 on adsorption of the bacteria to the mineral, ferric iron leaching, and bacterial leaching. The adsorption rate of the bacteria was fairly rapid in comparison with the bioleaching rate, indicating that the bacterial adsorption is at equilibrium during the leaching process. The adsorption equilibrium data were correlated by the Langmuir isotherm, which is a useful means for predicting the number of bacteria adsorbed on the mineral surface. The rate of chemical leaching varied with the concentration of ferric iron, and the first-order reaction rate constant was determined. Bioleaching in an iron-containing medium was found to take place by both direct bacterial attack on the sulfide mineral and indirect attack via ferric iron. In this case, the ferric iron was formed from the reaction product (ferrous iron) through the biological oxidation reaction. To develop rate expressions for the kinetics of bacterial growth and zinc leaching, the two bacterial actions were considered. The key parameters appearing in the rate equations, the growth yield and specific growth rate of adsorbed bacteria, were evaluated by curve fitting using the experimental data. This kinetic model allowed us to predict the liquid-phase concentrations of the leached zinc and free cells during the batch bioleaching process.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Adsorption of γ-globulin, a model protein for antibody, on colloidal particles (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 537-543 
    Details
    ISSN: 0006-3592
    Keywords: colloidal particles ; γ-globulin ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of surface properties on the adsorption of bovine γ-globulin, a model protein for antibody, was studied. Polystyrene latex (PS), hydrophilic copolymer lattices of styrene/2-hydroxyethyl methacrylate [P(S/HEMA)], styrene/ methacrylic acid [P(S/MAA)] and methyl methacrylate/ 2-hydroxyethyl methacrylate [P(MMA/HEMA)], and colloidal silica were used. The adsorption isotherms of γ-globulin on these colloidal particles were measured as a function of pH and ionic strength. The hydrophilic particles showed low affinities for γ-globulin at alkaline pH, while PS showed high affinities for γ-globulin over the whole range of pH and ionic strength. The γ-globulin adsorption on hydrophilic particles was highly reversible with respect to the pH and ionic strength compared with that on PS. These differences indicate that the dominant driving forces of adsorption are related to the hydrophilicity of particles. The adsorption isotherms of all colloidal particles showed the plateau values, and the order of maximum values of plateau adsorption was P(S/MAA) 〉 PS or P(S/HEMA), silica 〉 P(MMA/HEMA). Thus, they were also affected by the charged groups and the hydrophilicity of the surfaces. On the other hand, the plateau values of all colloidal particles were more or less symmetrical with a maximum at around the isoelectric point of γ-globulin at an ionic strength of 0.01. This behavior is attributed to the important role of the lateral interaction between the adsorbed molecules at low ionic strength.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260370607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    A proposed biparticle fluidized-bed for lactic acid fermentation and simultaneous adsorption (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 365-368 
    Details
    ISSN: 0006-3592
    Keywords: fermentation ; adsorption ; lactic acid ; fluidized bed ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A bioreactor configuration is proposed for simultaneous fermentation and separation of the desired product. The bioreactor consists of a columnar fluidized bed of immobilized microorganisms. Denser adsorbent particles are added to this column. These adsorbent particles fall through the bed, absorb the product, and are removed from the base of the columnar reactor. The system hydrodynamics and the separability of the two types of particles were confirmed for low-density gel beads. The addition of the adsorbent, activated carbon, to a fermentation of Lactobacillus delbreuckii absorbed lactic acid. The addition of adsorbent enhanced the fermentation and controlled the pH.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Epoxidation of propene by microbial cells immobilized on inorhanic supports (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 522-528 
    Details
    ISSN: 0006-3592
    Keywords: inorganic supports ; gas-utilizing micro-organisms ; adsorption ; double immobuilization ; propene epoxidation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Immobilization of gas-utilizing microorganism strains (Mycobacteria, Rhodococcus, methane-utilizers) on inorganic supports based on alumina, silicates, and carbon was carried out to develop heterogeneous biocatalysts for the biotechnologic processes, including the process of propene epoxidation. Adsorption ability of these microorganisms, biocatalytic properties of resting and immobilized bacterial cells, and effect of immobilization tehniques on biocatalysis were studied. An approach of double immobilization using inorganic materials (supports and gel) was proposed as simple, universal, and available methopd to immobilize bacterial cells, resulting in a higher retention (up to 100%) of cells' enzymatic activity and enhanced stability.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Methanotrophic attached-film reactor development and biofilm characteristics (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 1218-1232 
    Details
    ISSN: 0006-3592
    Keywords: methanotroph ; biofilm ; fluidized-bed ; attached-film ; film thickness ; film density ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The feasibility of using methanotrophs in an attached-film, fluidized-bed (MAFFB) reactor system has been under investigation since 1987. Mixed culture, methane-utilizing attached biofilms were developed on diatomaceous earth particles and on granular activated carbon. The required feed gases, methane and oxygen, were supplied to the attached biofilm in disolved form using separate gas-liquid aeration columns. Biofilm growth was steady despite low influent dissolved methane concentrations (1 to 3 mg/L). A breeder MAFFB operated consistently for 4.1 years with attached biofilm concentrations as high as 51.7 g VS/L static-bed with minimal biomass wasting and with minimal buffer and nutrient inputs. The maximum biomass concentration observed was 75.6 g VS/L static-bed in a MAFFB reactor treating trichloroethene. Biofilm thickness reached 160 μm with typical values of 70 μm under methane and oxygen growht-rate-limited conditions. Biofilm densities of 120 to 190 g VS/L film were observed. Growth rates varied from 〈0.01/d to 0.17/d. Greater than 90% of the biomass concentration in the bed was attached, and effluent total suspended solids ranged from 5 to 74 mg/L, with an average of 24 mg/L over 27 runs in four MAFFB systems at upflow velocities of 11.4 to 25 m/h. Heterotrophic attached-film methanotrophs appear to be stable and useful for applications in toxics treatment, and other product manipulations. © 1992 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260401012
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Intrinsic fermentation kinetics of lactose in acidogenic biofilms (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 479-488 
    Details
    ISSN: 0006-3592
    Keywords: acidogenesis kinetics ; lactose ; lactose ; biofilm ; mass transfer resistance ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The intrinsic fermentation kinetics of lactose in acidogenic biofilms were investigated in situ in a continuous flow fermentor at 35°C and pH 4.6. The external and internal mass transfer resistances to lactose molecules from bulk solution to inside the biofilms were experimentally minimized or eliminated in a thin biofilm and recycled medium. In a chemically defined culture medium, the immobilized acidogens converted lactose mainly to acetate and butyrate; the minor products included ethanol. propionate, lactate, and hydrogen. The utilization rate of lactose, as a function of lactose concentration in the fermentor, can be described by a Michaelis-Menten equation, as can the formation rates of acetate, butyrate, and ethanol. The production rates of propionate and lactate had a liner relationship with lactose concentration under the experimental conditions. The low pH (4.6) of culture medium could depress the formation of propionate, and intermediate which is most difficulty digested by acetogenic bacteria located in the second fermentor in a two-phase process. Production rate of acetate quickly reached a constant, and additional utilization of lactose produced more butyrate and other minor products. © 1993 John Wiley & Sons, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410412
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Biological sulphate reduction using gas-lift reactors fed with hydrogen and carbon dioxide as energy and carbon source (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 586-594 
    Details
    ISSN: 0006-3592
    Keywords: sulphate-reducing bacteria ; biofilm ; granulation ; gas-lift reactor ; hydrogen sulphide toxicity ; mass transfer ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Feasibility and engineering aspects of biological sulphate reduction in gas-lift reactors were studied. Hydrogen and carbon dioxide were used as energy and carbon source. Attention was paid to biofilm formation, sulphide toxicity, sulphate conversion rate optimization, and gasliquid mass transfer limitations. Sulphate-reducing bacteria formed stable biofilms on pumice particles. Biofilm formation was not observed when basalt particles were used. However, use of basalt particles led to the formation of granules of sulphate-reducing biomass. The sulphate-reducing bacteria, grown on pumice, easily adapted to free H2S concentrations up to 450 mg/L. Biofilm growth rate then equilibrated biomass loss rate. These high free H2S concentrations caused reversible inhibition rather than acute toxicity. When free H2S concentrations were kept below 450 mg/L, a maximum sulphate conversion rate of 30 g SO42-/L · d could be achieved after only 10 days of operation. Gas-to-liquid hydrogen mass transfer capacity of the reactor determined the maximum sulphate conversion rate. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Formation and growth of heterotrophic aerobic biofilms on small suspended particles in airlift reactors (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 595-608 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; aerobic waste water treatment ; airlift reactor ; waste water ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In this article, the conditions for aerobic biofilm formation on suspended particles, the dynamics of biofilm formation, and the biomass production during the start-up of a Biofilm Airlift Suspension reactor (BAS reactor) have been studied. The dynamics of biofilm formation during start up in the biofilm airlift suspension reactor follows three consecutive stages: bare carrier, microcolonies or patchy biofilms on the carrier, and biofilms completely covering the carrier. The effect of hydraulic retention time and of substrate loading rate on the formation of biofilms were investigated. To obtain in a BAS reactor a high biomass concentration and predominantly continuous biofilms, which completely surround the carrier, the hydraulic retention time must be shorter than the inverse of the maximum growth rate of the suspended bacteria. At longer hydraulic retention times, a low amount of attached biomass can be present on the carrier material as patchy biofilms. During the start-up at short hydraulic retention times the bare carrier concentration decreases, the amount of biomass per biofilm particle remains constant, and biomass increase in the reactor is due to increasing numbers of biofilm particles. The substrate surface loading rate has effect only on the amount of biomass on the biofilm particle. A higher surface load leads to a thicker biofilm.A strong nonlinear increase of the concentration of attached biomass in time was observed. This can be explained by a decreased abrasion of the biofilm particles due to the decreasing concentration of bare carriers. The detachment rate per biofilm area during the start-up is independent of the substrate loading rate, but depends strongly upon the bare carrier concentration.The Pirt-maintenance concept is applicable to BAS reactors. Surplus biomass production is diminished at high biomass concentrations. The average maximal yield of biomass on substrate during the experiments presented in this article was 0.44 ± 0.08 C-mol/C-mol, the maintenance value 0.019 ± 0.012 C-mol/(C-mol h). The lowest actual biomass yield measured in this study was 0.15 C-mol/C-mol. © 1994 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Development of effective modified cellulase for cellulose hydrolysis process (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 366-373 
    Details
    ISSN: 0006-3592
    Keywords: enzymatic hydrolysis ; cellulase ; polyoxyalkylene ; adsorption ; reactive two-phase partition ; solubilization in organic solvent ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Cellulase was modified with amphilic copolymers made of α-allyl-ω-methoxy polyoxyalkylene (POA) and maleic acid anhydride (MAA) to improve the cellulose hydrolytic reactivity and cellulase separation. Amino groups of the cellulase molecule are covalently coupled with the MAA functional groups of the copolymer. At the maximum degree of modification (DM) of 55%, the modified cellulase activity retained more than 80% of the unmodified native cellulase activity. The modified cellulase shows greater stability against temperature, pH, and organic solvents, and demonstrated greater conversion of substrate than native cellulase does. Cellulase modification is also useful for controlling strong adsorption of cellulase onto substrate. Moreover, cellulase modified with the amphiphilic copolymer displays different separation characteristics which are new. One is a reactive two-phase partition and another is solubility in organic solvents. It appears that these characteristics of modified cellulase work very effectively in the hydrolysis of cellulose as a total system, which constitutes the purification of cellulase from culture broth, hydrolysis of cellulose, and recovery of cellulase from the reaction mixture. © 1995 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450411
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Effect of polymeric adsorbents on the production of sanguinarine by Papaver somniferum cell cultures (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 971-977 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; benzophenanthridine alkaloid ; sanguinarine ; plant cells ; suspension culture ; elicitation ; Papaver somniferum ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The suitability of adsorbent polymeric resins, Amberlite XAD-4 and XAD-7 (Rohm and Hass, Inc.), was investigated for the accumulation of sanguinarine from Papaver somniferum cell cultures. The adsorption and desorption of sanguinarine from aqueous solution was most effective with XAD-7. In addition to sanguinarine, the resins were found to absorb growth regulators and vitamins from the culture medium. Growth inhibition was overcome by delaying for ∼4 days resin addition after cell inoculation in fresh medium. Resin addition (5% wt/vol) to actively growing uneclicited cultures led to increases in sanguinarine production and release of 30% to 40% and 60%, respectively. The addition of resins to elicited cultures led to increases in alkaloid production of up to 50% to 85% with similar increases in alkaloid release as observed for nonelicited cells. Overall yield of sanguinarine increased from 21 mg · g biomass dry weight-1 (dw) for elicited cultures to more than 39 mg · gdw-1 when elicitation was combined with resin addition. Higher quantities of resin (10% to 20% wt/vol) increased marginally the release of sanguinarine into the medium, and on the resin, up to 85% of total production. The use of resin appears promesing for the development of a bioprocess for sanguinarine production by cultured plant cells. © 1992 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260400813
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    A model of biofilm detachment (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 111-117 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; detachment ; model ; physiology ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A general mathematical framework for modeling biofilm detachment is presented. The approach is founded on a material balance on biomass that equates the detachment rate to the product of a detachment frequency and a detaching particle mass. The model provides a theoretical basis for deriving many of the empirical detachment rate expressions in common use and can thus lend some insight into their physical and biological significance. By allowing for variation in the detachment frequency with depth in the biofilm, the model permits derivation of detachment expressions that reflect a dependence on chemical or physiological gradients in the biofilm. Analysis of literature data sets from two different biofilm systems suggests, in both cases, that detachment is a growth-associated phenomenon. © 1993 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Adsorption of BSA on QAE-dextran: Equilibria (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 280-286 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; ion exchange ; equilibrium ; QAE dextran ; bovine serum albumin ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Equilibrium isotherms for adsorption of bovine serum albumin (BSA) on a strong-base (QAE) dextran-type ion exchanger have been determined experimentally. They were not affected by the initial concentration of BSA but were affected by pH considerably. They were correlated by the Langmuir equation when pH ≥ 5.05 and by the Freundlich equation of pH 4.8, which is close to pl ≃ 4.8 of BSA. The contribution of ion exchange to adsorption of BSA on the ion exchanger was determined experimentally. The maximum amounts of inorganic anion exchanged for BSA were 1% and 0.4% of the exchange capacity of the ion exchanger at pH 6.9, respectively. Since the effect of the ion exchange on the adsorption appeared small, BSA may be adsorbed mainly by electrostatic attraction when pH ≥ 5.05 and by hydrophobic interaction or hydrogen bonding at pH 4.8. When NaCl coexisted in the solution, the shape of the isotherm was similar to the Langmuir isotherm, but it is shifted to the right. When the concentration of NaCl was 0.2 mol/dm3, BsA was not adsorbed on the resin. When BSA was dissolved in pure water, the saturation capacity of BSA on HPO42-,-orm resin was about 2 times larger than that for adsorption from the solution with buffer (pH 6.9 and 8.79). The saturation capacity for adsorption of BSA in pure water on HPO42- + H2O4--from resin was much smaller than that from the solution with buffer. The isotherms for univalent Cl--and H2PO4--form resin was peculiar; that is, the amount of BSA adsorbed decreased with increasing the liquid-phase equilibrium concentration of BSA. © 1993 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Transport of 1-μm latex particles in pseudomonas aeruginosa biofilms (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 111-117 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; particle ; Pseudomonas aeruginosa ; transport ; roughness ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fluorescent latex microbeads added to a Pseudomonas aeruginosa biofilm as tracers of particle movement penetrated the biofilm and remained in it much longer than predicted by a model of advective displacement due to cell growth. Beads with a nominal diameter of 1 μm that were added in the bulk fluid became distributed throughout the biofilm depth. Some microbeads penetrated to the substratum within the 24-h bead addition period. The biofilms had a mean thickness of approximately 34 μm but have been previously shown to be quite rough. Measured rates of bead release from the biofilm corresponded to first order time coefficients of 0.01-0.03 h-1. These bead release rates were approximately an order of magnitude less than the predicted time scale of advective transport, which is just the experimentally measured specific cellular growth rate of 0.15 h-1. Computer simulations of bead transport using the biofilm model BIOSIM were compared with bead release rate data and with bead position distributions within the biofilm as determined by microscopic examination of thin cross sections of embedded biofilm. The model predicted much faster release of beads from the biofilm than actually occurred. It is hypothesized that both the ability of beads to penetrate the biofilm and the unexpectedly low advective displacement velocity of particles in the biofilm were due to the rough nature of the biofilm. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Interactions of microbial biofilms with toxic trace metals: 2. Prediction and verification of an integrated computer model of lead (II) distribution in the presence of microbial activity (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 232-239 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; extracellular biopolymer ; lead microbe interaction ; metal toxicity ; structured models ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The interfacial interactions of a toxic trace metal, Pb, with a surface modified by a marine film-forming bacterium, Psedomonas atlantica, were predicted by a structured biofilm model used in conjunction with a chemical speciation model. The validity of the integrated model was tested for batch and continuous operations. Dynamic responses of the biophase due to transient lead concentration increases were also stimulated. The reasonable pre dictions achieved by the model demonstrate its utility in describing trace metal distributions in complex systems where the adsorption properties of inorganic surfaces are modified by adherent bacteria production of extracellular polymers. © 1994 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Interactions of microbial biofilms with toxic trace metals: 1. Observation and modeling of cell growth, attachment, and production of extracellular polymer (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 219-231 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; structured models ; extracellular biopolymer ; microbial attachment/detachment ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Adsorbent surfaces in natural and engineered systems are frequently modifies by bacterial attachment, growth of a biofilm, and bacterial production of extracellular polymer. Attached cells or sorbed polymers may alter the metal-binding characteristics of the supporting substratum and influence metal partitioning. The interdependent behavior of toxic trace metal partitioning and biofilm development requires description of the interaction between cell growth with its accompanying polymer production and metal speciation. In this article, the first of a two part series, a mechanistic model is developed to describe the growth of a film-forming bacterium which adheres to a substratum through the production of extracellular biopolymers. Each bacterial cell was modeled as a two-component structure consisting of active cell mass and biopolymer. The biopolymer component was further divided into cell-associated and dissolved categories to distinguish which remained naturally bound to cell surfaces from that which did not. Use of this structured model permitted independent description of the dynamics of cell growth, and polymer production, both of which may influence trace metal behavior. Employing parameters obtained from independent experiments as well as published values, the model satisfactorily predicts experimental observations of bacterial growth, attachment and detachment, biopolymer production, and adsorption of polymer onto solid (glass) surfaces. The model stimulated transient and steady-state biofilm systems equally well. In the second article in this series, we describe how this model may be extended and utilized to make predictions of the behavior of transient and steady-state biofilm systems in the presence of a toxic transition metal(Pb). © 1994 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Specific quantification of trichoderma reesei cellulases in reconstituted mixtures and its application to cellulase-cellulose binding studies (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 961-966 
    Details
    ISSN: 0006-3592
    Keywords: cellobiohydrolase ; endoglucanase ; adsorption ; hydrolytic efficiency ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Specific quantifications of the major cellulolytic components of the Trichoderma reesei enzyme complex, i.e., endoglucanases I and III and cellobiohydrolases I and II, are described and, employing a defined mixture of these four cellulases reconstituted according to the composition of the native Trichoderma cellulase complex, used to determine the binding of each individual component onto filter paper. During substrate degradation by this enzyme mixture, the specific adsorption of each individual cellulase gradually increases and no preferential binding of one enzyme component in any particular phase of cellulose hydrolysis is found. T. reesei cellobiohydrolases I and II admixed with endoglucanases I and III represent a “full-value” cellulase system that is capable of degrading semicrystalline cellulose efficiently. In comparison with the crude Trichoderma enzyme complex, almost identical adsorption properties and similar hydrolytic efficiency are found for the reconstituted mixture. © 1994 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440812
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    The existence of a biological equilibrium in a trickling filter for waste gas purification (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 1279-1287 
    Details
    ISSN: 0006-3592
    Keywords: waste gas ; trickling filter ; biofilm ; dichlo-romethane ; biofiltration ; air pollution ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Clogging is well-known phenomenon in the application of a biological tricking filter for both waste gas and wastewater treatment. Nevertheless, no such observations or even significant changes in pressure drop have ever been recorded during the long-term processing of a waste gas containing dichloromethane (DCM) as a sole carbon source. To obtain more information about this phenomenon, a detailed investigation into the carbon balance of this system has been performed. During a period of operation of about 200 days the rate of DCM elimination and the overall rate of CO2 production in a continuously operating filter were therefore recorded daily, thus allowing an evaluation of the overall conversion process. Furthermore pseudo-steady-state measurements were carried out on a regular basis. These experiments reveal more detailed information on the actual DCM conversion by Hyphomicrobium GJ21 within the biofilm. The combined results of the experiments described in this article show that on an overall basis a so-called biological equilibrium, i.e., a situation of no net biomass accumulation, is obtained in the course of time. It appeared that the overall rate of CO2 production slowly increased until, after some 200 days, it finally counter-balanced the conversion rate of DCM on a molar-basis. As opposed to this result, all pseudo-steady-state experiments indicated that about 60% of the eliminated primary carbon source is converted into biomass. This is in good agreements with results from microkinetic experiments. Based on these results and evaluation of the experimental data, it is concluded that interactions between several microbial populations are involved in this biological equilibrium. These interactions include both biomass growth and biomass degradation. © 1994 John Wiley & Sons, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260441103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Formation of nitrifying biofilms on small suspended particles in airlift reactors (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 47 (1995), S. 585-595 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; wastewater treatment ; airlift reactor ; nitrification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For a stable and reliable operation of a BAS-reactor a high, active biomass concentration is required with mainly biofilm-covered carriers. The effect of reactor conditions on the formation of nitrifying biofilms in BAS-reactors was investigated in this article. A start-up strategy to obtain predominantly biofilm-covered carriers, based on the balancing of detachment and a biomass production per carrier surface area, proved tp be very successful. The amount of biomass and the fraction of covered carrier were high and development of nitrification activity was fast, leading to a volumetric conversion of 5 kgN · m-3 · d-1 at a hydraulic retention time of 1h. A 1-week, continuous inoculation with suspended purely nitrifying microorganisms resulted in a swift start-up compared with batch addition of a small number of biofilms with some nitrification activity. The development of nitrifying biofilms was very similar to the formation of heterotrophic biofilms. In contrast to heterotrophic bio-films, the diameter of nitrifying biofilms increased during start-up. The detachment rate from nitrifying biofilms decreased with lower concentrations of bare carrier, in a fashion comparable with heterotrophic biofilms, but the nitrifying biofilms were much more robust and resistant. Standard diffusion theory combined with reaction kinetics are capable of predicting the activity and conversion of biofilms on small suspended particles. © 1995 John Wiley & Sons Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260470511
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Hydrodynamics and performance in fluidized bed adsorption (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 48 (1995), S. 367-374 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; fluidization ; hydrodynamics ; proteinpurification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The performance of fluidized bed adsorption is strongly influenced by the hydrodynamics of the fluidization process. Especially axial mixing in the liquid and solid phase may lead to reduced capacity and resolution. In this article axial mixing in the liquid phase of a classified fluidized bed based on porous glass granules is presented. Axial mixing was analyzed by measurements of residence time distributions in a fluidized bed, showing a reduction of mixing at increased ratio of bed height to diameter as well as at increased linear velocity of the liquid stream. These results were transferred to two real adsorption systems on two different scales: In a bench scale (up to 15 mL of adsorbent) the purification of monoclonal antibodies from hybridoma supernatant was performed with a cation exchanger, in a larger scale (up to 750 mL of matrix) the adsorption of bovine serum albumin (BSA) on the same matrix was investigated. The results showed an increase of capacity at increased bed height-to-diameter ratio; with regard to linear velocity a broad range of only slightly changed capacity was found. A shift from dispersion controlled to diffusion controlled adsorption at intermediate linear velocity was proposed by isolating the effect of pore diffusion from the effect of dispersion. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260480409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Flotation of Streptomyces pilosus after lead accumulation (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 955-959 
    Details
    ISSN: 0006-3592
    Keywords: flotation ; Streptomyces pilosus ; lead ; adsorption ; sodium dodecylsulfate ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The flotation of Streptomyces pilosus was studied in the absence and presence of adsorbed Pb(II) ions on the cell walls and with and without using sodium dodecylsulfate (SDS) as collector. Adsorption of SDS onto the organism in the absence and presence of Pb(II) ions was also investigated. It was found that in the absence of adsorbed Pb(II), very little flotation took place with or without the presence of SDS although SDS adsorbed to some extent on the organism. The presence of Pb(II) on the bacterium's cell walls significantly increased flotation even in the absence of the collector. Addition of SDS, however, further increased both flotation rate and recovery.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260371009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Use of coimmobilized biological systems to degrade toxic organic compounds (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 273-279 
    Details
    ISSN: 0006-3592
    Keywords: coimmobilization ; Phanerochaete chrysosporium ; pentachlorophenol ; biodegradation ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The concept of coimmobilizing cell mass (and/or enzyme) and adsorbent in a hydrogel matrix for biodegradation of toxic organic chemicals was introduced. Under defined experimental conditions, the coimmobilized system using activated carbon and Phanerochaete chrysosporium was compared with nonimmobilized systems for the degradation of pentachlorophenol (PCP). It was demonstrated that the coimmobilized system degraded PCP more effectively than the nonimmobilized system. A solid substrate included in the coimmobilized system could support the biodegradation. Isolation of the degrading agents from a model interrupting microorganism by the coimmobilized capsule membrane reduced the interference on the biodegradation. In simulated contaminated soil extract and sand, the coimmobilized system also exhibited higher degradative ability and stability than the nonimmobilized systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260380309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Effect of adsorbents on degradation of toxic organic compounds by coimmobilized systems (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 619-628 
    Details
    ISSN: 0006-3592
    Keywords: biodegradation ; pentachlorophenol ; coimmobilization ; mathematical modeling ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The use of coimmobilized systems for treatment of toxic organic compounds has been proposed. The proposed approach combines the use of adsorbents and laboratory identified microorganisms immobilized in a protective permeable barrier to achieve a greater degree of control over the remediation process. This study was launched to understand the effect of adsorbents and changes in adsorption on the degradation of toxic compounds by coimmobilized systems. The specific case studied involved the degradation of pentachlorophenol (PCP) by Arthrobacter (ATCC 33790) coimmobilized with powdered activated carbon within calcium alginate capsules.The design parameters studied included adsorbent content and type as well as the effect of solution pH and surfactant concentration on adsorption and biodegradation. It was found that the equilibrium adsorption behavior of PCP was strongly influenced by solution pH and surfactant concentration. A mathematical model was developed that combined the physical processes of mass transfer and adsorption with biological degradation of PCP. The model was used to predict the effect of various parameters on the degradation of PCP. Based on model predictions, the degradation of PCP. Based on model predictions, the degradation of PCP was strongly dependent on variations in adsorbent capacity and affinity for this contaminant.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Plasmid retention and gene expression in suspended and biofilm cultures of recombinant Escherichia coli DH5α(pMJR1750) (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 211-220 
    Details
    ISSN: 0006-3592
    Keywords: plasmid retention ; gene expression ; biofilm ; β-galactosidase ; segregational instability ; Escherichia coli ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Differences in plasmid retention and expression are studied in both suspended and biofilm cultures of Escherichia coli DH5α(PMJR1750). An alternative mathematical model is proposed which allows the determination of plasmid loss probability in both suspended batch and continuously fed biofilm cultures. In our experiments, the average probability of plasmid loss of E. coli DH5α(pMJR1750) is 0.0022 in batch culture in the absence of antibiotic selection pressure and inducer. Under the induction of 0.17 MM IPTG, the maximum growth rate of plasmid-bearing cells in suspended batch culture dropped from 0.45 h-1 to 0.35 h-1 and the β-galactosidase concentration reached an experimental maximum of 0.32. pg/cell 4 hours after the initiation of induction. At both 0.34 and 0.51 mM IPTG, growth rates in batch cultures decreased to 0.16 h-1, about 36% of that without IPTG, and the β-galactosidase concentration reached an experimental maximum of 0.47 pg/cell 3 hours after induction.In biofilm cultures, both plasmid-bearing and plasmid-free cells in increase with time reaching a plateau after 96 hours n the absence of both the inducer and any antibiotic selection pressure. Average probability of plasmid loss for biofilm-bound E. coli DH5β(pMJR1750) population was 0.017 without antibiotic selection. Once the inducer IPTG was added, the concentration of plasmid-bearing cells in biofilm dropped dramatically while plasmid-free cell numbers maintained unaffected. The β-galactosidase concentration reached a maximum in all biofilm experiments 24 hours after induction; they were 0.08, 0.1, and 0.12 pg/cel under 0.17, 0.34, and 0.51 mM IPTG, respectively. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Development and experimental evaluation of a steady-state, multispecies biofilm model (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 914-922 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; competition ; modeling ; multispecies ; nitrification ; species distribution ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A steady-state model for quantifying the space competition in multispecies biofilms is developed. The model includes multiple active species, inert biomass, substrate utilization and diffusion within the biofilm, external mass transport, and detachment phenomena. It predicts the steady-state values of biofilm thickness, species distribution, and substrate fluxes. An experimental evaluation is carried out in completely mixed biofilm reactors in which slow-growing nitrifying bacteria compete with acetate-utilizing heterotrophs. The experimental results show that the model successfully describes the space competition. In particular, increasing acetate concentrations causes NH4+-N fluxes to decrease, because nitrifiers are forced deeper into the biofilm, where they experience greater mass-transport resistance.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390906
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    An experimental study of mass diffusion and reaction rate in an anaerobic biofilm (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 1141-1146 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; diffusion ; diffusivity ; immobilized cells ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental reactor consisting of two chambers, separated by a porous ceramic immobilization matrix, was constructed to measure the effective diffusivity of different compounds and the consumption rates of acetate in developing biofilms. In initial experiments, effective diffusivities for acetate, propionate, isopropanol, and lithium salt through the ceramic immobilization matrix in the absence of biofilm were determined to be 40% to 50% less than in water at infinite dilution. The effective diffusivity of the lithium salt was similar to that of acetate. The effective diffusivity of the lithium salt through biofilms of thickness in the range of 200 to 1200 μm was essentially constant with a value of approximately 7% of that in water at infinite dilution. Acetate consumption in the biofilm was linearly proportional to biofilm thickness up to a biofilm depth of 800 μm. Deviation from linearity appeared in biofilm thicknesses greater than 800 μm. Results of these experiments support previous reports that immobilized cell reactors have significantly higher bioconversion rates than suspended cell systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260391110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    The effects of surface adsorption on the thermal stability of proteins (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 8-15 
    Details
    ISSN: 0006-3592
    Keywords: adsorption ; silica ; proteins ; lysozyme ; surface polarity ; protein stability ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of surface adsorption on the structure and stability of proteins is a matter of increasing interest in biotechnology. Therefore, we have examined the effect of adsorption to silica on the thermal stability of 7 proteins employing differential scanning calorimetry (DSC) and front surface fluorescence (FSF) spectroscopy. In general, it was found that surface adsorption decreased the thermal stability of the bound protein. Using lysozyme for further studies, DSC, FSF, and FTIR spectroscopies, as well as enzymatic activity measurements, were used to explore the effect of decreasing surface apolarity on stability. It was observed that increasing surface apolarity produced decreasing stability and increasing structural alteration of the adsorbed protein.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260400103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    A new approach for modeling cellulase-cellulose adsorption and the kinetics of the enzymatic hydrolysis of microcrystalline cellulose (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 469-479 
    Details
    ISSN: 0006-3592
    Keywords: cellulase ; cellulose ; adsorption ; kinetics ; mathematical model ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two fractions of substrate in microcrystalline cellulose which differ in their adsorption capacities for the cellulases and their susceptibility to enzymatic attack have been identified. On the basis of a two-substrate hypothesis, mathematical models to describe enzyme adsorption and the kinetics of hydrolysis have been derived. A new nonequilibrium approach was chosen to predict cellulase-cellulose adsorption. A maximum binding capacity of 76 mg protein per gram substrate and a half-maximum saturation constant of 26 filter paper units (FPU) per gram substrate have been calculated, and a linear relationship of hydrolysis rate vs. adsorbed protein has been found. The fraction of substrate more easily hydrolyzed, as calculated from hydrolysis data, represents 19% of the total effective substrate concentration. This fraction is only slightly different from that of other celluloses and has been estimated to be 27% and 30% for NaOH- and H3PO4-swollen cellulose, respectively. The effective substrate concentration is equal to the maximum amount of the substrate which can be converted during exhaustive hydrolysis. This in turn is determined by the overall degradability of the substrate by the cellulases (85-90% for microcrystalline cellulose) and by the cellobiose concentration during hydrolysis. The kinetic model is based on a summation of two integrated first-order reactions with respect to the effective substrate concentration. Furthermore, it includes the principal factors influencing the reaction rates: the ratio of filter paper and β-glucosidase units per gram substrate and the initial substrate concentration. © 1993 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420410
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Adsorption of Clostridium thermocellum cellulases onto pretreated mixed hardwood, avicel, and lignin (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 899-907 
    Details
    ISSN: 0006-3592
    Keywords: C. thermocellum ; cellulase ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Adsorption of Avicel-hydrolyzing activity was examined with respect to: mixed hardwood flour pretreated with 1% sulfuric acid for 9 s at 220°C (PTW220), lignin prepared from PTW220 by either acid or enzymatic hydrolysis, and Avicel. Experiments were conducted at 60°C for all materials, and also at 25°C for PTW220. Based on transient adsorption results and reaction rates, times were selected at which to characterize adsorption at 60°C as follows: PTW220, 1 min; lignin, 30 min; and Avicel, 45 min. Similar results were obtained for adsorption of cellulase activity to PTW220 at 25 and 60°C, and for lignin prepared by enzymatic and acid hydrolysis. For all materials, adsorption was described well by a Langmuir equation, although the reversibility of adsorption was not investigated. Langmuir affinity constants (L/g) were: PTW220, 109; lignin, 17.9; Avicel, 4.3; cellulose from PTW220, ≥187. Langmuir capacity constants were 760 for PTW220 and 42 for Avicel; the cellulase binding capacity of lignin appeared to be very high under the conditions examined, and could not be determined. At low and moderate cellulase loadings at least, the majority of cellulase activity adsorbed to PTW220 is bound to the cellulosic component. The results indicate that PTW220, and its cellulose component in particular, differ radically from Avicel with respect to adsorption. Avicel-hydrolyzing activity and CMC-hydrolyzing activities were found to bind to Avicel with a constant ratio of essentially one, consistent with adsorption of a multi-activity complex. © 1993 John Wiley & Sons, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420715
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Liquid flow in heterogeneous biofilms (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 636-641 
    Details
    ISSN: 0006-3592
    Keywords: biofilm ; hydrodynamics ; mass transport ; particle tracking ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Liquid flow was studied in aerobic biofilms, consisting of microbial cell clusters (discrete aggregates of densely packed cells) and interstitial voids. Fluorescein microinjection was used as a qualitative technique to determine the presence of flow in cell clusters and voids. Flow velocity profiles were determined by tracking fluorescent latex spheres using confocal microscopy. Liquid was flowing through the voids and was stagnant in the cell clusters. Consequently, in voids both diffusion and convection may contribute to mass transfer, whereas in cell clusters diffusion is the dominant factor. The flow velocity in the biofilm depended on the average flow velocity of the bulk liquid. The velocity profiles in biofilms were linear and the velocity was zero at the substratum surface. The velocity gradients within biofilms were 50% of that near walls without biofilm coverage. The influence of the biofilm roughness on the flow velocity profiles was similar to that caused by rigid roughness elements. © 1994 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Adsorption and synergism of cellobiohydrolase I and II of Trichoderma reesei during hydrolysis of microcrystalline cellulose (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 1064-1073 
    Details
    ISSN: 0006-3592
    Keywords: Trichoderma reesei ; cellulase ; cellulose hydrolysis ; adsorption ; synergism ; FPLC ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Hydrolysis of microcrystalline cellulose (Avicel) by cellobiohydrolase I and II (CBH I and II) from Trichoderma reesei has been studied. Adsorption and synergism of the enzymes were investigated. Experiments were performed at different temperatures and enzyme/substrate ratios using CBH I and CBH II alone and in reconstituted equimolar mixtures. Fast protein liquid chromatography (FPLC) analysis was found to be an accurate and reproducible method to follow the enzyme adsorption. A linear correlation was found between the conversion and the amount of adsorbed enzyme when Avicel was hydrolyzed by increasing amounts of CBH I and/or CBH II. CBH I had lower specific activity compared to CBH II although, over a wide concentration range, more CBH I was adsorbed than CBH II. Synergism between the cellobiohy-drolases during hydrolysis of the amorphous fraction of Avicel showed a maximum as a function of total enzyme concentration. Synergism measured as a function of bound enzyme showed a continuous increase, which indicates that by decreasing the distance between the two enzymes the synergism is enhanced. The adsorption process for both enzymes was slow. Depending on the enzyme/substrate ratio it took 30-90 min to reach 95% of the equilibrium binding. The amount of bound enzyme decreased with increasing temperature. The two enzymes compete for the adsorption sites but also bind to specific sites. Stronger competition for adsorption sites was shown by CBH I. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Effects of sudden pressure changes in the surrounding gas phase on flow properties of bulk solidsPaper presented at the “Jahrestreffen der Verfahrens-Ingenieure”, Berlin, September 27 to 29, 1989. (1991)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 14 (1991), S. 53-59 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The variation in the behaviour of bulk solids as a result of sudden pressure changes in the surrounding gas phase is of interest in the application of lock hoppers for transfer of bulk solids into pressure vessels. By using such sluice systems, problems occur due to consolidation of the pressurized bulk solids. This paper presents the results of experimental and theoretical research, which allow to describe the influence of several parameters on pressure compensation and the degree of consolidation. With reference to the forces and mechanisms responsible for consolidation, it is possible to describe the different consolidation behaviour of incompressible (limestone) and compressible (hard coal) bulk solids.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270140108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Flow characteristics of large oscillating drops in liquid-liquid systems (1991)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 14 (1991), S. 65-72 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A study was made of the flow characteristics of large oscillating drops of pure liquid-liquid systems, using a thermostatically-controlled, rising drop column, 50 mm in diameter and 1000 mm in length. Mirrors in the jacket enabled front and side views of drops to be photographed simultaneously. Single drops in the size range 5-10 mm were investigated with both mutually-saturated phases and when the solute was being transferred from the dispersed phase. The systems studied were (1) toluene and acetone (dispersed)-water (continuous), and (2) n-heptane and acetone (dispersed)-water (continuous). Acetone concentrations were varied up to 3.75 kmol/m3. The oscillations of a travelling drop were asymmetrical; therefore, the amplitude cannot be expressed accurately in terms of only two axes. The area change of the drop compared to that of a sphere of equal volume ‘ε’, was shown to represent the amplitude accurately. The periods of droplet oscillation were uniform for the mutually saturated systems of constant physical and flow properties but changed when mass transfer was taking place. The interfacial tension exerted a marked effect on the amplitude, which also depended upon the oscillation frequency. The amplitude changed with droplet size in a similar manner to the terminal velocity, i.e. it increased with increasing size until it reached a maximum, subsequently decreasing less rapidly. The drag coefficient increased with increasing rate of mass transfer from the drop. Correlation of the results and the area eccentricity ‘ε’ by dimensional analysis embracing all possible parameters and physical properties affecting drop oscillation, resulted in the correlation ε = 0.22 Sr0.42 We-0.53 M0.13 with a mean deviation of ± 14%. This will facilitate more accurate prediction of the interfacial area for mass transfer calculations, relating to equipment containing droplets in the oscillating regime.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270140110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Development of rate expressions for the catalytic decomposition of nitric oxide with ammonia on iron oxide (1991)
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 14 (1991), S. 113-117 
    Details
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The reduction of nitric oxide with ammonia on iron oxide catalysts has been studied in a continuous-flow recycle reactor using simulated flue gas in the temperature range from 573 to 673 K. NO and HN3 concentrations were varied between 0 and 1000 vpm, O2 and H2O concentrations between 0 and 9 vol.-%, the remainder being nitrogen. In the presence of oxygen, the formulated reaction rate equation describes the measured rates of the main reaction NO + 2/3 NH3 ⇄ 5/6 N2 + H2O. Its form corresponds to the Langmuir-Hinshelwood type. The rate equation well fits the data, which cover the whole industrial temperature and concentration range. In the absence of oxygen, the measured reaction rates can be best described by a power law.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ceat.270140208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...