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  (2,327)
  • Springer  (2,327)
  • Oxford University Press
  • 2020-2023
  • 1995-1999  (2,327)
  • 1995  (2,327)
  • Process Engineering, Biotechnology, Nutrition Technology  (2,327)
Collection
  • Articles  (2,327)
Source
Keywords
Publisher
Years
  • 2020-2023
  • 1995-1999  (2,327)
Year
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    From the editor... (1995)
    Springer
    Adsorption 1 (1995), S. 5-5 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704141
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Controlled gas adsorption properties of various pillared clays (1995)
    Springer
    Adsorption 1 (1995), S. 49-59 
    Details
    ISSN: 1572-8757
    Keywords: measurement method ; mathematical model ; zeolite ; intraparticle diffusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Microporous pillared clays (PILC) were prepared by the intercalation of montmorillonite with particles of titania (Ti-PILC), zirconia (Zr-PILC), alumina (Al-PILC), iron oxide (Fe-PILC) and mixed lanthania/alumina (LaAl-PILC). Nitrogen adsorption isotherms (77 K) and XRD data provided information on the porosity, surface area, micropore volume and interlayer distance of these samples. The surface area varied between 198 and 266 m2/g for Ti- and Fe-PILC, respectively. The titania pillared clay had also the highest micropore volume (0.142 cc/g) and interlayer spacing (16–20 Å), compared to the Zr-PILC, which had the smallest spacing between the layers (max, 4 Å). Despite this fact, Zr-PILC always showed a high adsorption capacity for gases such as N2, O2, Ar or CO2, due to its high adsorption field in the very small micropores. From gas adsorption experiments on these various PILCs, it became clear that their adsorption properties depend on the pillars in three ways: (i) the pillar height, (ii) the distribution of the pillars between the clay layers and (iii) the nature of the pillaring species. The incorporation of other elements in the pillars leads to specific adsorption sites in the pores. This was demonstrated by the preparation of mixed Fe/Cr and Fe/Zr pillared clays. Compared to the parent Fe-PILC, the incorporation of chromium and zirconium in the iron oxide pillars had a positive influence on the adsorption capacity. Also the modification of a PILC with cations increases both capacity and selectivity for gases. This was confirmed by the increased adsorption of N2, O2 and CO2 at 273 K on a Sr2+ exchanged Al-PILC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704145
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Adsorption of gas mixtures on solid surfaces, theory and computer simulation (1995)
    Springer
    Adsorption 1 (1995), S. 7-16 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A treatment of the thermodynamics of mixed gas adsorption is presented in which the gas-solid interface is three dimensional. Such a treatment yields an additional term as compared to two dimensional approaches. This additional term has significant consequences for the derivation of adsorbed solution theories, particularly at higher temperatures. Results are presented for a Grand Canonical Monte Carlo study of a model methane-ethane mixture in a carbonaceous slit pore. Comparison of single component and mixture results provides an unambiguous means of testing theories of adsorbed solutions and bears out the thermodynamic treatment presented in the previous section of the paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704142
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A simulation model of a high-capacity methane adsorptive storage system (1995)
    Springer
    Adsorption 1 (1995), S. 17-27 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A two-dimensional model is developed to describe the hydrodynamics, heat transfer and adsorption phenomena associated with the adsorptive storage of natural gas (NG) in cylindrical reservoirs. Intraparticle and film resistances to both heat and mass transfer are neglected. In the momentum equation, Ergun's law is considered locally valid and is extended to two dimensions. These assumptions are fully justified in the paper. Numerical results are presented concerning the pressurization and blowdown of an ultra-lightweight 50 litre cylinder, commercially available for the storage of compressed NG, if it were filled with an activated carbon having a good adsorptive storage capacity. A simple formula is also proposed to predict the filling times for fast charges. The predicted temperature changes in the packed-bed are in good agreement with those reported in the literature for an experimental charge/discharge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704143
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Determination of transport coefficients in microporous solids (1995)
    Springer
    Adsorption 1 (1995), S. 29-48 
    Details
    ISSN: 1572-8757
    Keywords: measurement method ; mathematical model ; zeolite ; intraparticle diffusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Macroscopic transient methods are reviewed with respect to their applicability to the investigation of molecular transport in microporous sorption systems. Various levels of sophistication of data evaluation for nonequilibrium sorption results obtained by means of batch methods are identified and characterised. Special attention is paid to the characterisation ofFickian (intracrystalline) diffusion as well as to the identification and quantification of additional rate mechanisms that, in general, may simultaneously occur in molecular sieve systems. A state-of-art determination of transport coefficients is exemplified for the systems benzene/microporous gallosilicate of MFI-type, n-hexane/silicalite-I and p-ethyltoluene/ZSM-5. Their sorption rate behaviour can be understood either byFickian diffusion or byFickian diffusion and intracrystalline molecular immobilisation/mobilisation and surface barrier penetration, respectively. To analyse complex sorption rate patterns in microporous systems, the method oftotal curve fitting with full parameter region consideration becomes mandatory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Monolayer cuprous chloride dispersed on pillared clays for olefin-paraffin separations by π-complexation (1995)
    Springer
    Adsorption 1 (1995), S. 61-75 
    Details
    ISSN: 1572-8757
    Keywords: π-complexation sorbents ; pillared clays ; olefin-paraffin separations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract New adsorbents containing cuprous chloride dispersed on pillared interlayered clays (PILC) have been prepared and studied for olefin-paraffin separations. High surface-area PILC's were synthesized with different metal oxide (Al2O3, Fe2O3, TiO2 and ZrO2) as the intercalating pillars. Cuprous chloride was dispersed in a submonolayer form on these PILC's. Pure-component isotherms were measured for C2H4, C2H6, C3H6 and C3H8 at 25°C and 60°C. All sorbents exhibited high C2H4/C2H6 and C3H6/C3H8 ratios with significantly high amounts of olefins adsorbed. The best sorbent was CuCl/TiO2-PILC which showed a C2H4/C2H6 ratio of 5.3 and C3H6/C3H8=2.9 at 25°C. In all cases, olefins adsorbed by π-complexation with Cu(I) ion, reflected by heats of adsorption in the range 10.7–13.7 kcal/mol, as compared to 4.8–6.9 kcal/mol for the physical adsorption of the paraffins. The π-complexation was fully reversible, limited only by the rates of pore diffusion. Diffusion of C2's was rapid while for C3's the diffusion reached 60% completion in approximately 6 min. Comparing these results with those of CuCl/γ-Al2O3, the olefin/paraffin adsorption ratios were not as high as those of the later. However, the olefin isotherms on the PILC-supported CuCl displayed the desirable feature of having a steeper portion above the knee of the isotherm (the knee occurred at below 0.1 atm). This was a useful feature for separation because it yielded a larger working capacity. The steeper isotherm was attributed to a higher degree of energy heterogeneity as the PILC contained both surfaces of pillars and clay layers as opposed to only γ-Al2O3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704146
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Physisorption of alcohols and water vapour by MCM-41, a model mesoporous adsorbent (1995)
    Springer
    Adsorption 1 (1995), S. 77-82 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Adsorption isotherms of methanol, ethanol, propan-1-ol, butan-1-ol and water vapour have been determined on MCM-41, a model mesoporous adsorbent. The isotherms of the alcohols are all of Type IV, whereas the water isotherm is of Type V in the IUPAC classification. Each adsorption isotherm exhibits a sharp step, indicative of capillary condensation within a narrow distribution of mesopores. The isotherms are reversible in the monolayer-multilayer region, but distinctive hysteresis loops are associated with the condensation-evaporation cycle. The area within the loop is dependent on the adsorptive, increasing in scale from methanol to butan-1-ol and water. It is evident that the large internal surface of MCM-41 is somewhat hydrophobic and that its mesopore structure is remarkably uniform and stable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704147
    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
    Optimum isotherm equation and thermodynamic interpretation for aqueous 1,1,2-trichloroethene adsorption isotherms on three adsorbents (1995)
    Springer
    Adsorption 1 (1995), S. 113-132 
    Details
    ISSN: 1572-8757
    Keywords: adsorbent properties ; liquid phase adsorption isotherms ; activated carbon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Aqueous 1,1,2-trichloroethene (TCE) adsorption isotherms were obtained on Ambersorb1® 563 and 572 adsorbents and Filtrasorb2® 400 granular activated carbon (GAC). The data for Ambersorb 563 adsorbent covers TCE concentrations from 0.0009 to 600 mg/L. The data for each adsorbent was fit to 15 isotherm equations to determine an optimum equation. The best equation for the TCE adsorption isotherms is the Dubinin-Astakov (DA) isotherm. The DA isotherm coefficients were used to estimate the TCE micropore volume and the adsorption potential distribution. For each adsorbent, the TCE micropore volume is equivalent to the N2 porosimetry micropore volume. The mean adsorption potential is 18.8, 13.0, and 8.9 kJ/mol, with coefficients of variation of 0.37, 0.53, and 0.67, for Ambersorb 563 and 572 adsorbents and Filtrasorb 400 GAC, respectively. Thus, Ambersorb 563 adsorbent has the most energetic and most homogeneous adsorption volume, while Filtrasorb 400 GAC has the least energetic and most heterogeneous adsorption volume. For these reasons, Ambersorb 563 adsorbent has the highest TCE capacity at low concentrations, whereas Filtrasorb 400 GAC has the highest TCE capacity at high concentrations. The performance of Ambersorb 572 adsorbent is generally intermediate to the other two adsorbents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705000
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Adsoprtion and adsorptive separations: A bibliographical update (1992–1993) (1995)
    Springer
    Adsorption 1 (1995), S. 83-97 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This article provides a bibliographic listing of published journal papers concerned with adsorptive separations during 1992–1993. The references are taken from the 40 most important chemical engineering journals. This paper provides an update to the literature as provided in previous bibliographic papers [1, 2]. These previous papers also included membrane-type separations, however due to the number of papers and the diversity of membrane and associated processes, this material is to be published separately [3]. Other bibliographic papers covering the more traditional unit operations, e.g. distillation [4], and equilibrium-staged separations in general [5, 6] have been published. Liquid-liquid extraction [7] is the subject of a separate bibliography (for 1992–1993), due to the number of publications on this topic. A bibliography detailing supercritical extraction from 1980–1993 is also to be published separately due to the current interest in this relatively new technology [8]. A complete bibliography of the chemical engineering journal literature from 1967–1993 has been published by the author [9–12]. An earlier bibliography [13] provides access to the literature prior to 1967.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704148
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Upcoming adsorption meetings (1995)
    Springer
    Adsorption 1 (1995), S. 175-176 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705004
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Density of He adsorbed in micropores at 4.2K (1995)
    Springer
    Adsorption 1 (1995), S. 165-173 
    Details
    ISSN: 1572-8757
    Keywords: He adsorption ; micropore ; ultramicroporosity ; N2 adsorption ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The density of He adsorbed in the cylindrical micropores of zeolites NaY and KL has been determined by He adsorption at 4.2K. He adsorption isotherms were then compared with N2 adsorption isotherms at 77K. Crystallographic considerations of the micropore volumes gave the density of the He adsorbed layer, which is necessary for assessment of ultramicroporosity of less-crystalline microporous solids, such as activated carbons. The determined density of He adsorbed in the cylindrical micropores of the zeolite was in the range 0.22 to 0.26 gml−1, greater than that of He adsorbed on a flat surface (0.202 gml−1). A value for the density of He between 0.20 to 0.22 gml−1 is recommended for evaluation of ultramicroporosity of a slit-shaped microporous system such as activated carbon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705003
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Sensitivity of PSA process performance to input variables (1995)
    Springer
    Adsorption 1 (1995), S. 133-151 
    Details
    ISSN: 1572-8757
    Keywords: PSA process ; sensitivity ; equilibria ; kinetics ; heats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Mathematical models for pressure swing adsorption (PSA) processes essentially require the simultaneous solutions of mass, heat and momentum balance equations for each step of the process using appropriate boundary conditions for the steps. The key model input variables needed for estimating the separation performance of the process are the multicomponent adsorption equilibria, kinetics and heats of adsorption for the system of interest. A very detailed model of an adiabatic Skarstrom PSA cycle for production of high purity methane from a ethylene-methane bulk mixture is developed to study the sensitivity of the process performance to the input variables. The adsorption equilibria are described by the heterogeneous Toth model which accounts for variations of isosteric heats of adsorption of the components with adsorbate loading. A linear driving force model is used to describe the kinetics. The study shows that small errors in the heats of adsorption of the components can severely alter the overall performance of the process (methane recovery and productivity). The adsorptive mass transfer coefficients of the components also must be known fairly accurately in order to obtain precise separation performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705001
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Radial flow rapid pressure swing adsorption (1995)
    Springer
    Adsorption 1 (1995), S. 153-164 
    Details
    ISSN: 1572-8757
    Keywords: bulk separation ; pressure swing adsorption ; radial flow chromatography ; air separation ; oxygen enrichment ; zeolite 5A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A new PSA process has been proposed and experimentally verified. This process was operated with a radial flow geometry under a cycle time less than 30 seconds. It has been showed that enriched oxygen could be produced when air was fed inward. The same system showed virtually no separation effect if the feed direction was reversed. The change of separation efficiency upon flow reversal was most significant when small adsorbent particles were employed. A ø 200×75 mm annular packing with 3 µm particles of zeolite 5A was able to produce 60% purity oxygen from air. The effect of flow direction on system performance confirmed the importance of flow resistance distribution. In radial flow geometry, most of the flow resistance was located near the center of the disk. The relative small pressure gradient at the feed end enabled a better absorbent utilization during the inward feed step, and a more effective desorption during the vent step. The same principle could be extended to other geometric configurations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705002
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Second international symposium effects of surface heterogeneity in adsorption and catalysis on solids (ISSHAC) Poland-Slovakia, September 4th–10th, 1995 (1995)
    Springer
    Adsorption 1 (1995), S. 177-178 
    Details
    ISSN: 1572-8757
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705005
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Predicting isotherms in micropores for different molecules and temperatures from a known isotherm by improved Horvath-Kawazoe equations (1995)
    Springer
    Adsorption 1 (1995), S. 187-196 
    Details
    ISSN: 1572-8757
    Keywords: micropore size distribution ; Horvath-Kawazoe equation ; isotherms from pore size distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Our improved Horvath-Kawazoe (H-K) equations (by considering the isotherm nonlinearity) for three pore geometries are first summarized. These equations apply to adsorption in microporous materials at subcritical temperatures. From a known isotherm at a given temperature, these equations are used to predict isotherms of the same adsorbate molecules at other temperatures, and also to predict isotherms for other adsorbate molecules at the same (or any subcritical) temperature. A reasonable agreement is obtained between predictions and experimental data. Since the H-K formulation only involves dispersion forces, it underpredicts for gas-solid systems in which other forces also exist. The N2-zeolite system is one of these systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704222
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Measurement of the diffusivity of benzene in microporous silica by quasi-elastic neutron scattering and NMR pulsed-field gradient technique (1995)
    Springer
    Adsorption 1 (1995), S. 197-201 
    Details
    ISSN: 1572-8757
    Keywords: silica ; self-diffusion ; measurements methods: pulsed-field gradient NMR and quasi-elastic neutron scattering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The diffusivity of benzene in a microporous silica powder has been measured by neutron scattering and NMR techniques. The measurements have been performed on un-supported silica but the powder has the same characteristics as the active layer of a real membrane. Self-diffusion coefficients of the order of 10−10 m2s−1 are found at 300 K by both techniques so that the model of Knudsen diffusion is not valid for benzene in this microporous material. Due to the presence of small pores, the diffusion of benzene in the membrane-material approaches the diffusion regime usually observed in zeolites. Furthermore, the diffusivity of benzene follows an Arrhenius law with an activation energy of 11 kJ mol−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704223
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Adsorptive separation by thermal parametric pumping part I: Modeling and simulation (1995)
    Springer
    Adsorption 1 (1995), S. 213-231 
    Details
    ISSN: 1572-8757
    Keywords: adsorptive separation ; thermal parametric pumping ; modeling ; simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A detailed model for the recuperative parametric pumping is presented. The model includes intraparticle mass transfer resistance, axial diffusion and non-linear equilibrium represented by Langmuir equation. The sensitivity studies shows that process performance strongly increases when cycle time increases and φ B /φ T ratio and particle size decreases. It also shows that bottom and top dead volumes do not influence much the process performance. Evolution of the histories of concentrations and temperatures, the bed performance from cycle to cycle and the bed dynamics at the cyclic steady state have been discussed. The model revealed itself as useful to simulate the behavior of the recuperative parametric pumping process and was applied to predict optimal experimental results for the system phenol-water/Duolite ES-861 (Part II).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704225
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Effect of variable feed concentration on the performance of a pressure swing adsorption process (1995)
    Springer
    Adsorption 1 (1995), S. 203-211 
    Details
    ISSN: 1572-8757
    Keywords: simulation ; pressure swing adsorption ; fixed bed system ; bulk separation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Effects of variable feed composition on the performance of a pressure swing adsorption process are analyzed by simulation. Two scenarios are considered. The first, “increasing impurity,” case considers low impurity concentration in the feed followed by high impurity concentration in the feed. The second, “decreasing impurity,” case considers high impurity concentration in the feed followed by low impurity concentration in the feed. These results are compared against a case which has an impurity concentration in the feed at an average of the high and the low impurity concentrations. Simulations show that the increasing impurity scenario is expected to perform better, and the decreasing impurity scenario is expected to perform worse than the average feed concentration case.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704224
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Adsorptive separation by thermal parametric pumping part II: Experimental study of the purification of aqueous phenolic solutions at pilot scale (1995)
    Springer
    Adsorption 1 (1995), S. 233-252 
    Details
    ISSN: 1572-8757
    Keywords: parametric pumping ; purification ; pilot plant ; phenolic solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In this work scale-up concerns in adsorptive parametric pumping operation in recuperative mode are studied. An experimental study of the purification of wastewater containing 100 ppm of phenol using a polymeric adsorbent (Duolite ES861-Rohm and Haas, France) is reported. A completely automated pilot plant (column and ancillary equipment, product receivers, sampling, collector and analytical devices) is described. The plant is computer controlled enabling automatic data acquisition for temperature, pressure and flowrate. Parameters related with adsorption equilibrium, mass transfer and heat transfer resistances were determined in order to obtain basic information to simulate the process behavior. Continuous and semicontinuous top feed parametric pumping experiments were carried out in a bed with 0.09 m diameter and 1 m long which represents a scale-up by a factor of 60 relative to previous works. Optimal operating conditions yielding the maximum productivity of the bottom product (phenol concentration 〈1 ppm), were achieved experimentally with the following conditions: average cycle time =4 h, ratioφ B /φ T =2 (φ B =0.27), reservoir volumeQ(π/ω)=32.5l, average flowrate=0.24l/min. Based on these conditions, after 12 cycles of operation, 105l of treated water is obtained. Those optimal operating conditions were suggested by simulation studies presented in Part I (Ferreira and Rodrigues, 1995) of this work. Good agreement was obtained between experimental and simulated results using the complete model developed in Part I (Ferreira and Rodrigues, 1995).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Interpretation of water isotherm hysteresis for an activated charcoal using stochastic pore networks (1995)
    Springer
    Adsorption 1 (1995), S. 253-264 
    Details
    ISSN: 1572-8757
    Keywords: water isotherms ; isotherm hysteresis ; activated charcoal ; pore size distribution ; pore networks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Water vapor adsorption equilibria on activated carbons typically exhibit hysteresis. The size and shape of the hysteresis loop which separates the adsorption and desorption branches is a strong function of the pore size and interconnectivity of the pores. Neither conventional pore filling models nor statistical thermodynamics approaches provide a means for predicting the extent of hysteresis from only adsorption measurements. This work uses the Kelvin Equation in conjunction with the structural concept of a stochastic pore network to describe measured water isotherms on BPL carbon. Using a pore segment distribution function determined from the adsorption branch, it is shown that totally random assemblies underestimate the extent of hysteresis. It is possible, however, to closely fit the measured BPL-water hysteresis loop using a patchy heterogeneity in which a proportion of the larger pores are preferentially located on the exterior, mid-range pores are concentrated in a sub-surface layer and some large pores form shielded voids behind much smaller pores.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704227
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Effect of pore size distribution on the surface diffusivity in activated carbon: Hybrid Dubinin-Langmuir isotherm (1995)
    Springer
    Adsorption 1 (1995), S. 291-301 
    Details
    ISSN: 1572-8757
    Keywords: hybrid isotherm ; darken ; surface diffusivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The concentration dependence of the observed surface diffusivity for activated carbon due to the pore size distribution is theoretically investigated. The mathematical model is derived based on the assumption of a local hybrid adsorption isotherm (proposed recently by Shethna and Bhatia, 1994) and a local surface diffusive flux for a particular pore of half widthr. Using those local quantities and assuming a Gamma pore size distribution, the observed surface diffusivity is obtained. This observed surface diffusivity was found to increase rapidly with loading if the chemical potential is the driving force for surface flow. Furthermore, this observed surface diffusivity,D/D(0), was found to be the same as the Darken thermodynamic correction factor, using only the macroscopic isotherm information. This indicates that the thermodynamic correction factor contains information on the averaging of the surface heterogeneity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707352
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Differential pressure-jump method for routine measurement of sorption kinetics (1995)
    Springer
    Adsorption 1 (1995), S. 265-273 
    Details
    ISSN: 1572-8757
    Keywords: porous solids ; sorption kinetics ; pressure-jump method ; diffusion coefficient ; tortuosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A sensitive pressure-jump method has been developed for the measurement and characterization of material transport in porous solids. The apparatus is automatically operated and the data evaluation is performed by means of numerical methods based on the Crank-Nicholson procedure. As an example, the sorption ofn-butane and ethene in spherical mesoporous silica gel pellets has been studied. In this way, it is possible to obtain uptake curves and in case of known particle shape to derive values for effective diffusion coefficients. From the pressure and temperature dependence ofD e , information on the transport mechanism by means of Knudsen and surface diffusion can be obtained as well as the tortuosity factor characterizing the pore network.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Theory of measurement of gas-adsorption equilibria by rotational oscillations (1995)
    Springer
    Adsorption 1 (1995), S. 283-290 
    Details
    ISSN: 1572-8757
    Keywords: gas adsorption equilibria ; measurement techniques ; gas phase ; rotational oscillations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The gas adsorbed on the inner surface of a highly porous material like activated carbon or zeolite can be measured by slow damped oscillations of a torsional pendulum. The physical principles and the theory of this method are outlined. Formulas are given relating the increase in mass due to adsorption to changes of the frequency and the logarithmic decrement of slow, damped rotational oscillations of the pendulum. Preliminary measurements of gas adsorption equilibria of nitrogen on activated carbon show that the ratio of the mass adsorbedm, to the mass of the adsorbentm s , can be determined by this method with mean absolute error δ|m/m s |≤0.04%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707351
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Waste heat driven solid sorption coolers containing heat pipes for thermo control (1995)
    Springer
    Adsorption 1 (1995), S. 303-312 
    Details
    ISSN: 1572-8757
    Keywords: heat pipe ; heat pump ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper provides a focus on the R&D of solid sorption coolers and heat pumps made in the Luikov Heat & Mass Transfer Institute (CIS Countries Association “Heat Pipes”) under Thermacore, Inc. Agreement. Commercial and space applications of sorbent systems offer an attractive alternative to compression systems and liquid sorption systems for cooling, heating and air conditioning. MgA zeolites solid sorption systems are analyzed. Some new results are presented. Solid sorption heat pump technology utilizing heat pipe heat recovery with a condensing/evaporating refrigerant holds considerable promise for bivariant (space and domestic) applications due to the variable temperature and variable load capabilities of such machines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707353
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Production of oxygen enriched air by rapid pressure swing adsorption (1995)
    Springer
    Adsorption 1 (1995), S. 313-320 
    Details
    ISSN: 1572-8757
    Keywords: pressure swing adsorption ; air separation ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A novel rapid pressure swing adsorption (RPSA) process is described for production of 25–50% oxygen enriched air. The embodiment consists of one or more pairs of adsorbent layers contained in a single adsorption vessel. The layers undergo simultaneous pressurization-adsorption and simultaneous depressurization-purge steps. A total cycle time of 6–20 seconds is used. The process yields a very large specific oxygen production rate and a reasonable oxygen recovery for production of 20–50 mole% oxygen enriched gas. It is demonstrated by a simple mathematical model of isothermal single adsorbate pressure swing ad(de)sorption concept on a single adsorbent particle that the specific production rate of a PSA process cannot be indefinitely increased by reducing the cycle time of operation when adsorbate mass transfer resistances are finite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707354
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Separation of a binary gas mixture by pressure swing adsorption: Comparison of different PSA cycles (1995)
    Springer
    Adsorption 1 (1995), S. 321-333 
    Details
    ISSN: 1572-8757
    Keywords: processes and applications—bulk separation ; simulation ; pressure swing adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Gas separation of a binary gas mixture by various pressure swing adsorption (PSA) cycles was studied by a numerical simulation in order to provide a guidance in selecting PSA cycles. PSA cycles considered in this study are 3, 4-step cycles for production of only one component and a cycle with pressure equalization for production of a light component. 4 and 5-step cycles for simultaneous production of both components of a binary gas mixture are also considered. Separation of a CH4/CO2 gas mixture with zeolite 5A was chosen as a case study. Performances of cycles were examined and compared in view of purity, recovery and productivity. Their relative advantages were discussed. Inclusion of a purging step to a 3-step cycle for production of only one component improves a cycle performance. Further performance improvement of a cycle for production of a light component can be achieved by employing pressure equalization. Sircar's 4-step cycle with a recycle of effluent shows the best performance in view of purity and recovery among cycles for simultaneous production of both components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00707355
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    FT-IR Determination of degree of esterification in polycarboxylic acid cross-link finishing of cotton (1995)
    Springer
    Cellulose 2 (1995), S. 31-39 
    Details
    ISSN: 1572-882X
    Keywords: FT-IR ; degree of esterification ; cross-link finishing ; cotton ; polycarboxylic acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Cross-linking of cotton with polycarboxylic acids, applied with catalysts based on phosphorus-containing inorganic acids, produces fabrics with excellent smooth-drying properties and which release no formaldehyde at any stage of preparation or on storage. The reaction produces cellulose ester linkages and unreacted carboxylic acid groups. Fourier transform infrared spectroscopy was used to determine the degree of esterification of polycarboxylic acids that occurred on cross-linking of cotton. The height of the carbonyl peak at 1730 cm −1 was determined on the same treated fabrics after soaking in dilute acid to convert ionized groups to free acid and then in dilute base to convert free acid to carboxylate ion. The carbonyl peak for the base rinsed fabric (ester only) was ratioed against the same peak for the acid-rinsed fabric (total carbonyl, ester plus acid) to obtain a measure of the degree of esterification. This ratio minimizes the problems of different molar extinction coefficients that are encountered when peaks from different functional groups are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Surface area of papermaking woodpulps used by the British paper industry (1995)
    Springer
    Cellulose 2 (1995), S. 83-94 
    Details
    ISSN: 1572-882X
    Keywords: surface area ; eucalyptus globulus sulphate pulp ; encalyptus grandis sulphate pulp ; betula verrucosa sulphate pulp ; pine/spruce sulphate pulp ; surface change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The surface area was determined for various papermaking woodpulps: bleached eucalyptus globulus sulphate pulp; bleached eucalyptus grandis sulphate pulp; bleached betula verrucosa sulphate pulp; bleached pine/spruce sulphate pulp; bleached pine/spruce sulphate pulp fines. The method of negative adsorption was used which gives an effective ‘wet’ surface area. By looking at negative adsorption data more closely, some inference can be made about the morphology of the substrate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00816382
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Surface characterization of cellulose fibres by XPS and inverse gas chromatography (1995)
    Springer
    Cellulose 2 (1995), S. 145-157 
    Details
    ISSN: 1572-882X
    Keywords: corona treatment ; surface energy ; XPS ; cellulose fibres ; inverse gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Inverse gas chromatography (IGC) was used to determine the dispersive component of the free energy as well as the acid-base properties of cellulose fibre surfaces, before and after modification by corona treatment. It was found that the corona treatment increases both the dispersive contribution to surface energy and its acidic character, whereas only a slight increase in its basicity was observed. It was also found that some chemical degradation of the surface occurs at high corona currents. The extent of modification of the surface properties, as revealed by IGC, was correlated to the surface chemical composition deduced from XPS analysis as well as with the electrical conductance and the pH of the water suspensions of the cellulose fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813015
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Effect of cellulase on the pore structure of bead cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 179-203 
    Details
    ISSN: 1572-882X
    Keywords: Enzymatic hydrolysis ; bead cellulose ; pore structure ; porosity measurements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An enzymatic treatment with cellulases fromTrichoderma viride was investigated in its effect on the pore structure of different types of bead cellulose. One objective of this study was to establish a suitable procedure for combined enzymatic treatment and solvent exchange that would restore the original pore structure which the beads had before drying without causing major losses in mechanical stability. Another aim was to further increase the accessible pore space and internal surface area for separation of large molecular weight compounds with regard to Chromatographic applications. Finally, an attempt was made to extend the findings for unsubstituted beads to the derivatives carboxymethyl (CM) and diethylaminoethyl (DEAE) cellulose beads. The enzymatically treated samples were characterized by microscopic methods and porosity measurements such as mercury porosimetry, nitrogen sorption and size exclusion chromatography. It was found that under controlled conditions the low-porosity surface layer of dried beads could be removed making the internal pore space accessible without reducing the resistance to deformation of the beads. Additionally, a shift in pore size distribution towards larger pores was observed. Supplementary swelling treatments in solvents of high swelling power could substantially restore the former porosity of the dried beads but did not enhance the accessibility to the cellulases to a considerable extent. Internal pore volume and surface area of the derivatives were dramatically increased in the case of DEAE upon enzymatic hydrolysis, however, at the expense of mechanical stability, whereas CM was found to be less affected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813017
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Monomeric dioxouranium(VI), chromium(III), cobalt(II), nickel(II) and copper(II) complexes with primary cellulose acetate (PCA) (1995)
    Springer
    Cellulose 2 (1995), S. 235-241 
    Details
    ISSN: 1572-882X
    Keywords: cellulose acetate ; ligand field parameters ; polymer complexes ; metal chelates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Monomeric UO 2 2+ , CrIII, COII, NiII and CuII complexes with primary cellulose acetate (PCA) have been prepared and characterized. Infrared,1H NMR, UV/visible spectroscopy, elemental analysis, therniogravimetry, conductance and magnetic measurements were used to assign the mode of coordination in the isolated species. The investigation revealed that PCA exhibits octahedral coordination with CrIII, CoII, NiII and a square planar form with CuII whereas the UO2 moiety is virtually linear. PCA acts as a neutral bidentate chelating agent via the two oxygen atoms of the vicinal ester groups in the secondary positions forming a five-membered chelate ring. A comparative study between chelates of PCA and those previously prepared with secondary cellulose acetate (SCA) has been undertaken.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811815
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Thermal properties of oxidized cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 41-49 
    Details
    ISSN: 1572-882X
    Keywords: Cellulose ; Oxidized cellulose ; Thermal analysis ; Stability ; Degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Three series of oxidized celluloses – 2,3-dialdehyde celluloses (DACs), 2,3-dicarboxycelluloses (DCCs) and sodium 2,3-dicarboxycelluloses (NaDCCs) — were prepared, having incremental changes in their degrees of oxidation. Their thermogravimetric analysis (TG) and differential thermal analysis (DTA) were studied. It was found that oxidation generally destabilized cellulose at lower temperatures (below ∼ 250 °C), but at higher temperatures the oxidized products were found to be more stable. Cellulose, DACs, and DCCs all showed final weight losses in the region of 80–85%. However, 80% NaDCC and 98% NaDCC showed weight losses of only 30 and 37%, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812771
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Carbon-13 NMR distinction between categories of molecular order and disorder in cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 95-110 
    Details
    ISSN: 1572-882X
    Keywords: nuclear magnetic resonance ; molecular disorder ; crystal surfaces
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Differences between values of proton rotating-frame spin relaxation time constants can be exploited to separate a solid-state13C NMR spectrum of cellulose into subspectra of crystalline and noncrystalline regions. Variations in chemical shifts and13C spin-lattice relaxation time constants can then be used to study variations in molecular order and disorder within each of the two broader categories. Mechanical damage during Wiley milling increases the content of noncrystalline cellulose and changes the nature of molecular disorder within that category. Resolution enhancement of the subspectrum assigned to crystalline cellulose reveals pairs of signals at 83.9 and 84.9 ppm (cellulose I) or 86.8 and 88.3 ppm (cellulose II) assigned to C-4 on well-ordered crystal surfaces. A broader peak in the subspectrum of crystalline cellulose I is assigned to poorly-ordered surfaces. Relative proportions in Avicel microcrystalline cellulose were estimated as: 54% in crystal interiors, 22% on well-ordered surfaces, 8% on poorly-ordered surfaces, 16% in domains of disorder extending more than a few nanometres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00816383
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Microstructural cumulative material degradation and fatigue-failure micromechanisms in wood-pulp fibres (1995)
    Springer
    Cellulose 2 (1995), S. 159-177 
    Details
    ISSN: 1572-882X
    Keywords: fibre ; fatigue ; micro-mechanisms ; morphology ; shear ; tension ; compression ; fibre development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper establishes the fundamental micro-mechanisms associated with the conversion of single wood pulp fibres into fibres suitable for the production of paper. It deals with an examination of the morphological and structural changes taking place in pulp fibres being subjected to cyclic mechanical actions that are representative of those experienced by fibres in mechanical refiners. Implementing the experimental procedure previously described (Hamad, 1994), qualitative answers are provided to such questions as what material property changes are associated with the various identifiable micro-mechanisms and how is the extent of damage accumulation related to wood species, pulping type, refining energy, and the number of cycles? A collation of the underlying themes responsible for material degradation indicates that a recognition of the regions of high-localized deformation and the manner in which cracks grow as well as the general weakening of the material due to structural damage and mechanical degradation of the fibre cell wall material, provide an insight into the way in which single fibres are rendered suitable for papermaking by mechanical refining.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813016
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Characterization of tension and normally lignified wood cellulose inPopulus maximowiczii (1995)
    Springer
    Cellulose 2 (1995), S. 223-233 
    Details
    ISSN: 1572-882X
    Keywords: wood cellulose ; two crystalline phase system ; CP/MAS13C NMR ; FT-IR ; electron diffraction ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract We have investigated unlignified tension wood and normally lignified wood celluloses inPopulus maximowiczii with particular reference to the composition of two crystalline phases Iα/Iβ (triclinic/ monoclinic). Four independent techniques, which enable us to detect the two phases, CP/MAS13C NMR, Fourier transform infrared microscopy, selected-area electron diffraction, and X-ray diffraction were applied. Because of the low crystallinity of wood celluloses, particularly in the case of celluloses in the lignified cell wall, no single method was decisive enough to be able to determine the composition of the two phases as one can with highly crystalline materials. The Iβ dominant structure (monoclinic crystal type) was, however, preferred for both tension and normal wood celluloses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    A multivariate characterization of crystal transformations of cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 273-288 
    Details
    ISSN: 1572-882X
    Keywords: Softwood pulp ; cotton linters ; cellulose crystals ; spectroscopy ; data analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A spectroscopic study of cellulose transformation processes, such as alkali treatment and annealing, showed that, in combination with multivariate data analysis techniques, a detailed understanding of the crystalline transformation processes could be reached.13C cross-polarization magic-angle spinning (CPMAS) NMR and near-infrared (NIR) spectroscopy of cotton linters and softwood pulps analysed during the processing revealed information, after data reduction using principal components data analysis, that could be connected to structural changes of the cellulose polymorphs. The data showed that alkali treatment of cotton linters led to a cellulose conversion from cellulose I to II, while annealing, both for linters and pulps, yielded a transformation from Iα to Iα.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811818
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Plasticization of cellulose diacetate with a mixture of triacetin and esters of butylcellosolve and aliphatic dicarboxylic acids (1995)
    Springer
    Cellulose 2 (1995), S. 23-29 
    Details
    ISSN: 1572-882X
    Keywords: plasticization ; ternary system ; phase diagram ; glass transition ; tensile creep
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The compatibility of cellulose diacetate with triacetin and esters of butylcellosolve with dicarboxylic aliphatic acids was studied for a wide range of compositions. The glass transition temperature T g ,the dielectric relaxation activation energy and the tensile creep for the plasticized systems were determined. It is shown that when the esters are added to triacetin in small amounts, which correspond to the formation of compatible systems, the plasticizing effect is enhanced and the molecular mobility of the system components is improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812769
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Some aspects of lateral chain order in cellulosics from X-ray scattering (1995)
    Springer
    Cellulose 2 (1995), S. 51-70 
    Details
    ISSN: 1572-882X
    Keywords: X-ray scattering ; crystallite dimensions ; lattice distortions ; microfibrils ; manmade fibres ; native cellulose ; alkalization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract This paper gives an overview of our recent research activities on the lateral supramolecular order of a variety of native and man-made cellulosics considering respective results from the literature. Wide-angle X-ray scattering (WAXS) was the main investigation technique used. Lateral root mean squared lattice strains between 2 and 3% were determined for the materials investigated. Crystallite sizes obtained without considering lattice distortions usually do not deviate by much more than −10% from the real, i.e. fully corrected values. This means that it is sufficient to use the simple Scherrer equation for determining lateral crystallite sizes for most routine investigations of cellulosic materials. The possible superposition of WAXS peaks of the triclinic Iα and monoclinic Iβ lattice types, however, has to be considered in crystallite size determinations for Valonia cellulose. It could be shown that neglecting this fact can lead to crystallite sizes being about 20% below the true ones. Lateral crystallite dimaensions for native celluloses vary between 4nm (dissolving pulps) and 10-15 nm (Valonia). Except for bacterial cellulose, the WAXS crystallite sizes are distinctly smaller than the microfibril dimensions obtained from electron microscopy. The man-made fibres investigated showed lateral crystallite dimensions between 3 and 5nm. The importance of lateral crystallite dimensions for the properties of man-made fibres and for the alkalization process of native cellulose id demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812772
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Influence of hemicelluloses on the aggregation patterns of bacterial cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 129-144 
    Details
    ISSN: 1572-882X
    Keywords: Acetobacter xylinum ; hemicellulose ; aggregation pattern ; fibril width ; crystallite size ; X-ray diffraction ; Raman spectroscopy ; transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Cellulose from the bacteriumAcetobacter xylinum was used as a model system for investigating the influence of other cell wall polysaccharides on the aggregation of cellulose. The patterns of aggregation of the bacterial cellulose were modified when the cellulose was produced in the presence of hemicellulose-like saccharides. The celluloses were found to be more like the Iβ-type found in higher plant celluloses than the Iα-type in the control bacterial celluloses. The effects of isolation procedures on structure were also explored. It was found that the structures of isolated celluloses were influenced by the procedures used in isolation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00816385
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Resolution of naftopidil and bufuralol enantiomers by high-performance liquid chromatography on cellulose tris-(3,5-dimethylphenyl carbamate) column (1995)
    Springer
    Cellulose 2 (1995), S. 215-221 
    Details
    ISSN: 1572-882X
    Keywords: naftopidil ; bufuralol ; enantiomer separation ; cellulose tris-(3,5-dimethylphenyl carbamate) chiral stationary phase ; chiral recognition mechanism(s) ; cellulose carbamates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The liquid Chromatographic resolution of the racemic cardiovascular drugs naftopidil and bufuralol to their corresponding enantiomers was achieved on cellulose tris-(3,5-dimethylphenyl carbamate) chiral stationary phase known as Chiralcel OD. The chiral recognition mechanism(s) involved between the chiral stationary phase and these drugs, which include hydrogen bonding, intercalative interactions, and steric interactions, among other factors, were discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813019
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Characterization of cellulose derivatives — Relevance to sensor development (1995)
    Springer
    Cellulose 2 (1995), S. 243-263 
    Details
    ISSN: 1572-882X
    Keywords: cellulose acetate ; cellulose acetate butyrate ; ethyl cellulose ; characterization ; biosensor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract With the aim of developing a urea biosensor, several cellulose derivatives were used to coat an all-solid-state potentiometric electrode for ammonium ion determination. In this work the physical and chemical characterization of the cellulose derivatives, as well as the changes that the activation and immobilization procedures induced in the polymers, were studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Swelling of compressed cellulose fiber webs in organic liquids (1995)
    Springer
    Cellulose 2 (1995), S. 1-22 
    Details
    ISSN: 1572-882X
    Keywords: Swelling of compressed fibers ; swelling of wood ; molar volume ; cohesive energy density ; hydrogen bonding parameter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Maximum liquid-holding capacities of various compressed fibers in water and in a series of various organic liquids have been investigated. The maximum liquid-holding capacity versus bulk density relationships gave polynomial curves, generally with a peak. Good relative correlations for cellulose, compressed fiber pellets and wood were found for the series of liquids tested. In general, liquids that swelled wood to a low to medium range (up to 6%) did not swell appreciably α-cellulose and sulfite pulp, while good to excellent wood-swelling agents swelled all the fibers very significantly. It was also found that the hydrogen-bonding parameter of the swelling liquid was the most important factor. The swelling rate of various compressed fiber systems in organic liquids was dramatically increased by raising the temperature. Activation energies and molar volume of the swelling liquid were linearly correlated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812768
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Changes in molecular ordering associated with alkali treatment and vacuum drying of cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 71-82 
    Details
    ISSN: 1572-882X
    Keywords: NMR spectroscopy ; alkali treatment ; dried/never-dried
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Carbon-13 NMR methods were used to monitor changes in the proportions of crystalline and non-crystalline cellulose, and the exposure of chains on crystallite surfaces, in samples of alkali-treated kraft pulp and regenerated cellulose. A large increase in the amount of disorderd cellulose, as a result of conversion to cellulose II, is the major effect of alkali treatment with kraft pulp. Removal of small crystallites is the major effect with regenerated cellulose. Samples were examined never-dried, or were vacuum-dried prior to remoistening for characterization. Changes in molecular ordering consistent with pore collapse and coalescence of crystallite surfaces accompanied the removal of water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00812773
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Ultrastructural aspects of the acetylation of cellulose (1995)
    Springer
    Cellulose 2 (1995), S. 111-127 
    Details
    ISSN: 1572-882X
    Keywords: acetylation ; cellulose acetate ; Valonia ; tunicin ; cellulose microcrystals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An ultrastructural study of the acetylation of cellulose was achieved by subjecting well characterized cellulose samples fromValonia cell wall and tunicin tests to homogeneous and heterogeneous acetylation. The study involved transmission electron microscopy observations on negatively stained microcrystals as well as diffraction contrast images of the cross sections of wall fragments at various stages of the reaction. These observations showed that the acetylation of crystalline cellulose proceeds by a reduction of the diameters of the crystals while their lengths are reduced to a lower extent. These results were corroborated by electron and X-ray diffraction experiments that showed that during the reaction there was a rapid decrease in the intensities of the equatorial diffraction spots of cellulose, whereas those located on the meridian or close to the meridian stayed constant. A model of acetylation of the cellulose crystal is presented. It is based on a non swelling reaction mechanism that affects only the cellulose chains located at the crystal surface. In the case of homogeneous acetylation, the partially acetylated molecules are sucked into the acetylating medium as soon as they are sufficiently soluble. In heterogeneous conditions the cellulose acetate remains insoluble and surrounds the crystalline core of unreacted cellulose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00816384
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Methyl cellulose-based edible films and coatings I. Effect of plasticizer content on water and 1-octen-3-ol sorption and transport (1995)
    Springer
    Cellulose 2 (1995), S. 205-213 
    Details
    ISSN: 1572-882X
    Keywords: Poly(ethylene glycol) ; 1-octen-3-ol ; permeation ; water vapour transfer rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Edible films were prepared from methyl cellulose with various concentrations of poly(ethylene glycol) 400 (PEG400) used as a plasticizer. Water vapour and 1-octen-3-ol (an aroma compound) were selected as hydrophilic and hydrophobic volatile penetrants respectively. Their solubility and permeability through methyl cellulose-based edible films were studied using gas chromatography methods. Whatever penetrant was used, the flux increased with the PEG400 content. Transfer behaviour, i.e., the order of increased magnitude of the transfer rate, strongly depends on the nature of the volatile compound. However, water sorption only depends on the PEG400 content whereas the aroma compound sorption is affected by both the water and the PEG400 concentrations. Relationships between solubility and permeability can be partially explained by the plasticization phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00813018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Bleaching of cellulose by hydrogen peroxide (1995)
    Springer
    Cellulose 2 (1995), S. 265-272 
    Details
    ISSN: 1572-882X
    Keywords: Hydrogen peroxide ; oxycellulose ; bleaching ; oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Peroxides are important bleaching agents, industrially, for cellulosic products. They are also used in detergents. Peroxides can degrade cellulose as well as decolorize it and remove stains. Both free radicals and perhydroxyl anions have been suggested as the intermediates in the reactions occurring between cellulosic products and hydrogen peroxide. The proposed mechanisms are reviewed with emphasis primarily on cotton cellulose. Further work is required to establish unequivocally the mechanism of degradation and decolorization of cellulose products.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00811817
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Mutants of carotene production in Blakeslea trispora (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 836-838 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The filamentous fungus Blakeslea trispora, an industrial carotene source, contains β-carotene and precursors of its synthesis – phytoene, phytofluene, lycopene, and γ-carotene. Strain improvement through mutagenesis is difficult because all life stages are multinucleate. Mutants have been obtained following exposure of wild-type spores to N-methyl-N′-nitro-N-nitroso- guanidine. Changes in the colour of the mycelia reflect variations in the accumulation of various precursors and the final product. Quantitative analysis of the mutants leads to the conclusion that the biosynthetic pathway is similar to that of the related fungus Phycomyces blakesleeanus, but the regulation is completely different. In particular, interruption of the pathway does not lead to overacummulation of precursors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Enzymatic peptide synthesis by the recombinant proline-specific endopeptidase from Flavobacterium meningosepticum and its mutationally altered Cys-556 variant (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 844-852 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Proline-specific endopeptidase (PSE) (EC 3.4.21.26) was investigated for its potential as a catalyst in peptide synthesis. Using an activated peptide ester or a peptide amide as the acyl component, the enzyme catalyzed kinetically controlled aminolysis and transpeptidation respectively, with various amino acid amides as acyl acceptors. To a certain extent the nucleophile preference reflected the amino acid preference in the S1′-position of the enzyme in peptide hydrolysis: the highest fractions of aminolysis were obtained using amino acid amides with hydrophobic side-chains (e.g. Leu-NH2, Phe-NH2). PSE also catalyzed the thermodynamically controlled condensation of short peptides with a free carboxyterminus and various amino acid amides. This enabled us to examine the acceptance of different acyl components in the substrate-binding site of the enzyme with regard to their amino acid composition: In the S1 position proline was clearly favored, but alanine was also accepted, whereas the S2 subsite accepted various amino acids rather unspecifically. Since PSE was shown to be extremely sensitive against water-miscible organic solvents, an alternative approach was used to increase yields in enzymatic peptide synthesis: a derivative of PSE in which the catalytic Ser-556 is converted to a Cys was constructed by protein engineering. This mutant (PSEcys) exhibited a dramatically increased peptide ligase activity in aqueous solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050341
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Stimulation of citric acid production in Aspergillus niger by addition of viscous substances in shake culture (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 839-843 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  When glucose (120 mg/ml) was used as a carbon source, Aspergillus niger Yang no. 2. showed a markedly low citric acid productivity in shake culture (15.4 mg/ml) but a high productivity in semi-solid and surface cultures (72.3 mg/ml and 67.6 mg/ml, respectively). Since the viscosity of the medium was assumed to be one of the important factors for citric acid productivity in shake culture, the effects of the addition of viscous substances on citric acid productivity of strain Yang no. 2 were examined. The addition of 2.0 – 6.0 mg gelatin/ml as a viscous additive to the medium containing glucose as a carbon source increased slightly the medium viscosity but substantially increased the citric acid productivity in shake culture to levels of 52.0 – 53.3 mg/ml, about 3.4 times as much as that without gelatin. However, no influence of gelatin addition was observed in semi-solid and surface cultures, i.e. under static cultivation conditions. Different mycelial morphologies of the strain were observed when cultivations were done in shake culture with or without the addition of gelatin. Addition of 5.0 mg agar/ml, 5.0 mg carageenan/ml, 2.5 mg carboxymethylcellulose/ml and 2.5 mg polyethylene glycol 6000/ml, to the medium containing glucose as a carbon source also increased the citric acid productivity in shake culture to levels of 39.2 – 54.7 mg/ml. Since Yang no. 2 does not utilize these viscous substances, these results suggested that the viscous substances functioned as protectants for the mycelium from physiological stresses due to shaking and as a consequence resulted in a remarkably increased citric acid productivity in shake culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050340
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Secretion by Saccharomyces cerevisiae of rat apolipoprotein E as a fusion to Mucor rennin (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 865-870 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  As the first step for production of rat apolipoprotein E (rApoE) in Saccharomyces cerevisiae, the rApoE cDNA was cloned and its nucleotide sequence was determined. When the intact rApoE gene including the presequence-encoding region was expressed under the control of the yeast GAL7 promoter, no protein immunoreactive with anti-rApoE antibody was detected either in the culture medium or inside the cells. For the purpose of the extracellular production of rApoE, three fusion genes were constructed in which the mature rApoE-encoding sequence was connected after the pre, prepro, and whole regions of the gene encoding a fungal aspartic proteinase, Mucor pusillus rennin (MPP), since MPP is efficiently secreted from recombinant S. cerevisiae containing the MPP gene. When these three fusion genes were expressed under the control of the GAL7 promoter, only one, encoding the mature rApoE connected to the whole MPP sequence, directed efficient secretion of the fused protein. The maximum yield of the fused protein secreted into the medium reached 11.8 mg/l and the calculated rApoE part was 5.3 mg in the fused protein. The excreted fusion protein was glycosylated at the original two sites in the MPP part. The fused protein was gradually degraded in the medium probably by proteases of the host cell, because no such degradation occurred in a yeast pep4mutant strain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050344
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    One-step enzymatic hydrolysis of starch using a recombinant strain of Saccharomyces cerevisiae producing α-amylase, glucoamylase and pullulanase (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 878-883 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A recombinant strain of Saccharomyces cerevisiae was constructed that contained the genes encoding a bacterial α-amylase (AMY1), a yeast glucoamylase (STA2) and a bacterial pullulanase (pulA). The Bacillus amyloliquefaciensα-amylase and S. cerevisiae var. diastaticus glucoamylase genes were expressed in S. cerevisiae using their native promoters and the encoded enzymes secreted under direction of their native leader sequences. In contrast, the Klebsiella pneumoniae pullulanase gene was placed under the control of the yeast alcohol dehydrogenase gene promoter (ADC1 P ) and secreted using the yeast mating pheromone α-factor secretion signal (MF α 1 S ). Transcription termination of the pullulanase gene was effected by the yeast tryptophan synthase gene terminator (TRP5 T ), whereas termination of the glucoamylase and α-amylase genes was directed by their native terminators. Pullulanase (PUL1) produced by recombinant yeasts containing ADC1 P MF α 1 S pulA TRP5 T (designated PUL1) was further characterized and compared to its bacterial counterpart (PulA). The different genes were introduced into S. cerevisiae in different combinations and the various amylolytic Saccharomyces transformants compared to Schwanniomyces occidentalis. Introduction of PUL1 into a S. cerevisiae strain containing both STA2 and AMY1, resulted in 99% assimilation of starch
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050346
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Mitomycin C stimulates thermally induced recombinant gene expression in Escherichia coli MC strains (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 890-894 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The effects of mitomycin C on CI857-controlled recombinant gene expression have been explored in E. coli cultures when the drug was added simultaneously to the thermal induction. A significantly improved yield of homologous, heterologous and chimeric fusion proteins was observed in E. coli MC1061 and GE864 (a MC4100 derivative) thermoinduced cells. This feature was not detected in other E. coli strains and does not involve a gene dosage mechanism but a strain-dependent stimulation of gene expression unrelated to the RecA protease activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050348
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Cloning, DNA sequencing and heterologous expression of the gene for thermostable N-acylamino acid racemase from Amycolatopsis sp. TS-1-60 in Escherichia coli (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 884-889 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The gene encoding the novel enzyme N-acylamino acid racemase (AAR) was cloned in recombinant phage λ-4 from the DNA library of Amycolatopsis sp. TS-1-60, a rare actinomycete, using antiserum against the enzyme. The cloned gene was subcloned and transformed in Escherichia coli JM105 using pUC118 as a vector. The AAR gene consists of an open-reading frame of 1104 nucleotides, which specifies a 368-amino-acid protein with a molecular mass of 39 411Da. The molecular mass deduced from the AAR gene is in good agreement with the subunit molecular mass (40kDa) of AAR from Amycolatopsis sp. TS-1-60. The guanosine plus cytosine content of the AAR gene was about 70%. Athough the AAR gene uses the unusual initiation codon GTG, the gene was expressed in Escherichia coli using the lac promoter of pUC118. The amount of the enzyme produced by the transformant was 16 times that produced by Amycolatopsis sp. TS-1-60. When the unusual initiation codon GTG was changed to ATG, the enzyme productivity of the transformant increased to more than 37 times that of Amycolatopsis sp. TS-1 – 60. In the comparison of the DNA sequence and the deduced amino acid sequence of AAR with those of known racemases and epimerases in data bases, no significant sequence homology was found. However, AAR resembles mandelate racemase in that requires metal ions for enzyme activity. Comparison of the deduced amino acid sequences of mandelate racemase and AAR revealed amino acid sequences in AAR similar to those of both the catalytic and metal-ion-binding sites of mandelate racemase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050347
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Use of a polymerase-chain-reaction-amplified DNA probe from Pseudomonas putida to detect D-hydantoinase-producing microorganisms by direct colony hybridization (1995)
    Springer
    Applied microbiology and biotechnology 42 (1995), S. 895-900 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Pseudomonas putida strain DSM 84 produces N – carbamyl-D-amino acids from the corresponding D-5-monosubstituted hydantoins. The sequence of the D-hydantoinase gene from this strain (GenBank accession number L24157) was used to develop a DNA probe of 122 base pairs (bp) that could detect D-hydantoinase genes in other bacterial genera by DNA and by colony hybridization. Under conditions tolerating 32% mismatch, the probe was specific for all strains that expressed D-hydantoinase activity. These include Pseudomonadaceae of all rRNA groups, and bacteria belonging to the genera Agrobacterium, Serratia, Corynebacterium, and Arthrobacter. Environmental sampling was simulated by screening a mixture of unknown microorganisms from commercial inocula for the biodegradation of industrial, municipal and domestic wastes. The 122-bp probe was specific for microorganisms that subsequently demonstrated D-hydantoinase activity. Bacterial species from four different genera were detected, which were Pseudomonas, Klebsiella, Enterobacter, and Enterococcus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Microbial cometabolism of sucralose, a chlorinated disaccharide, in environmental samples (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 194-194 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170643
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    The lysins of bacteriophages infecting lactic acid bacteria (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 1-6 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  This short review highlights the complete absence of literature on lysins of bacteriophages infecting species like S. salivarius subsp. thermophilus, Pediococcus and Leuconostoc species, L. helveticus, L. acidophilus, L. plantarum and L. brevis, which are also widely used in the dairy industry. The lysins described share some similar biochemical characteristics: optimal pH and temperature, site of hydrolysis inside the peptidoglycan, and some activators and inhibitors. The clon- ing of the genes encoding these lysins only began in the last few years and four of them have been completely sequenced. In the future, these lysin genes could be interestingly compared to the host autolysin(s) gene(s). By contrast, the passage of phage lysins through the cytoplasmic membrane of the host cell in order to reach the peptidoglycan (via a signal sequence or the presence of a holin) seems not to be clearly resolved. The presence of a second open-reading frame upstream from the gene of the lysin, enabling a putative holin to be encoded, has already been suggested. No doubt our ever increasing knowledge about bacteriophage genome organization will help to elucidate this question. Meanwhile the obtention of a Lactococcus strain with an autolytic phenotype, using a bacteriophage lysin gene, as well as the successful use of purified PL1 lysin to obtain protoplasts of L. casei encourage us to continue to explore the field of bacteriophage lysins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050360
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    The effect of phosphate concentration on phytase production and the reduction of phytic acid content in canola meal by Aspergillus carbonarius during a solid-state fermentation process (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 25-30 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The use of canola meal, an abundant side-product of canola oil processing in Canada, as animal feed is hampered by high phytic acid levels that reduce metal cation availability. Aspergillus carbonarius grows well in a solid canola meal medium, produces phytase and reduces the phytic acid content to zero. Inorganic phosphate addition at a concentration of 1 mg and 5 mg/110 g solid-state culture system results in better growth of the microorganism, higher rates and levels of phytase production, and faster reduction of phytic acid content. Phosphate concentrations of 50 mg and 100 mg/110 g inoculated system had a negative effect affecting primarily the initial rates of biomass and phytase production and phytic acid content reduction. Models that predict biomass production (expressed as glucosamine content) and phytase, as well as the reduction of phytic acid content in the solid-state cultures supplemented with phosphate are reported. They fit the experimental results reasonably well (with a maximum deviation of 7%).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050364
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Analysis of Penicillin V biosynthesis during fed-batch cultivations with a high-yielding strain of Penicillium chrysogenum (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 123-130 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Metabolites (both intra- and extracellular) involved in penicillin biosynthesis were measured during fed-batch cultivations with a high-yielding strain of Penicillium chrysogenum. The fed-batch cultivations were carried out on a complex medium containing corn steep liquor. Three distinct phases were observed: (a) a rapid growth phase where free amino acids present in the medium are metabolized, (b) a linear growth phase, and (c) a stationary phase. The specific penicillin production (r p) is initially high and, during the rapid growth phase, it increases slightly. During the linear growth phase r p is approximately constant [4–6 mg penicillin V (g dry weight)-1 h-1 depending on the operating conditions], whereas it decreases during the stationary phase. During the cultivations the tripeptide Aad-Cys-Val (the first metabolite in penicillin biosynthesis) and 8-hydroxypenillic acid (formed by carboxylation of 6-aminopenicillanic acid, 6-APA) were found to accumulate in the medium, whereas the concentrations of isopenicillin N and 6-APA were found to be approximately constant and low. About 3% of the Aad-Cys-Val formed in the first step of the penicillin biosynthetic pathway is lost to the medium and 4% of the isopenicillin N formed in the second step of the pathway is lost as extracellular isopenicillin N, 6-APA or 8-hydroxypenillic acid. Also the cyclic form of α-aminoadipic acid, 6-oxo-piperidine-2-carboxylic acid, was found to accumulate in the medium and it was found to be formed in an approximately constant ratio to penicillin V of 6 mol/100 mol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050380
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Biodegradation of 2-chloroethanol by freely suspended and adsorbed immobilized Pseudomonas putida US2 in soil (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 143-149 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The degradation of 2-chloroethanol by Pseudomonas putida US2 was investigated in batch, repeated batch and continuous cultures especially in a packed-bed fermenter with sand. The degradation of 2-chloroethanol was connected with a release of protons, which led to a decrease of the pH in the medium. Higher initial concentration than 25 mM 2-chloroethanol were not degraded completely because they entailed a decrease of the pH to 5.0, which inhibited further growth and degradation. P. putida US2 showed a typical repression of catabolites and diauxic growth with succinate as cosubstrate. The addition of succinate as a second substrate caused a decrease in degradation of 2-chloroethanol. Activated sludge added to adsorbed cultures in a continuous fermentation did not lead to a decrease in metabolic activity. After 2 weeks of continuous cultivation the specialized strain could be retained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050383
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Kinetics of bio-oxidation of a medium comprising phenol and a mixture of organic contaminants (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 165-170 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The kinetics of bio-oxidation by a microbial ensemble of a model mixture of contaminants that mimicked the ground-water pollution plume at an existing contaminated site was investigated. Phenol at 50 mg/l and a mixture of ten organic contaminants (MOC) (benzene, tetrachloromethane, trichloroethylene, toluene, o-xylene, 1,4-dichlorobenzene, o-cresol, nitrobenzene, naphthalene and 2,6-dichlorophenol) at individual concentrations ranging from 150 μg/l to 600 μg/l were the components of the model mixture. The microbial ensemble consisted of at least three Pseudomonas spp. isolated from the polluted site. Patterns of oxygen uptake rate (OUR) for the oxidation of phenol alone and with added MOC were treated mathematically. The values for kinetic parameters that gave the best fit to the data were respectively 11.29 and 15.03 ml O2 h-1 (mg protein)-1 for the OUR maximum (OURmax), 75.89 mg/l and 33.66 mg/l for the saturation constant (K s), 105.92 mg/l and 36.44 mg/l for the inhibitor constant (K i), and 89.66 mg/l and 35.02 mg/l the substrate minimum inhibitory concentration (S mic). This study also scrutinised interference between the two components of the model mixture of contaminants (phenol and MOC) on the basis of variations in kinetic patterns. MOC was shown to be toxic at milligram per litre levels. The microbial ensemble increased phenol oxidation in response to MOC, possibly to obtain the energy to overcome this toxic effect. This was indicated by an acceleration of phenol oxidation in response to increasing concentrations of MOC and higher OURmax for oxidation of phenol in the presence of MOC. The toxicity of MOC also resulted in enhanced vulnerability of the microbial ensemble to a phenol inhibitory effect, indicated by the diminution of K i and S mic. The microbial ensemble showed high resistance to inhibition by the sole presence of phenol possibly because of adaptation to toxic features of MOC during the processes of enrichment and cultivation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050386
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Enhanced anaerobic degradation of benzene by enrichment of mixed microbial culture and optimization of the culture medium (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 178-187 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A heterogeneous mixed culture, originally collected from two different sources, namely cow-drug and sludge from the city waste-water treatment plant, was grown in mineral medium containing 1% glucose and then adapted on benzene as the carbon and energy source. Under anaerobic conditions benzene was degraded via benzoic acid as a major intermediate in the benzene degradation pathway. The degradation rate of benzene was improved stepwise by the number of enrichments and optimization of the culture medium. The effects of microaerobic conditions and/or physicochemical treatment with H2O2 prior to anaerobic degradation were studied with respect to variations in benzene degradation rate, growth of biomass and gas composition. It was noticed that the amount of gas produced is less than the theoretical value expected and the percentage of methane in the product gas was very small (3%–3.5%). The reason for this is not well understood but it is presumed that the major group of benzene-degrading bacteria present in the culture medium are sulphate reducers and the mixed consortium is unable to degrade certain complex aromatic intermediates in the benzene degradation pathway under the experimental conditions. For an actual explanation of the situation arising in this study, further investigations must be carried out. However, the mixed culture is capable of oxidizing benzene more rapidly to intermediate compounds and also partly into gas under the culture conditions, compared to the published data for the anaerobic degradation of benzene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050388
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Expression of Bacillus subtilis levanase gene in Lactobacilus plantarum and Lactobacillus casei (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 297-303 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Two Lactobacillus-Escherichia coli shuttle vectors, harbouring the levanase gene from Bacillus subtilis under the control of its own promoter (pLPEW1) or behind the E.coli tac promoter (pESIEW2), were constructed. Lactobacillus plantarum showed the same growth characteristics on selective plates and in liquid media containing inulin, after transformation with either pLPEW1 or pESIEW2. L. plantarum transformed with pLPEW1 could be selected on inulin plates, indicating that levanase expression can be used as a food-grade selection system for Lactobacillus. Lactobacillus casei grew faster in inulin-containing medium than L. plantarum after transformation with pESIEW2, but did not grow when harbouring pLPEW1. Inulin-degrading activities of 90 mU/ml were found in culture medium of L. plantarum containing pLPEW1 or pESIEW2, and of 500 mU/ml in medium of L. casei (pESIEW2). Addition of 1 mMm isopropyl β-d-thiogalactoside to the culture medium had no effect on growth and levanase expression in L. plantarum (pESIEW2) and L. casei (pESIEW2) strains. Levanase produced by L. casei (pESIEW2) has a size of 75 kDa and 72 kDa, corresponding to that of unprocessed and mature B. subtilis levanase, respectively, suggesting that the protein produced is recognized and processed by a signal peptidase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172828
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Sodium and proline accumulation in Corynebacterium glutamicum as a response to an osmotic saline upshock (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 315-320 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In order to understand the role of the medium osmolality on the metabolism of glumate-producing Corynebacterium glutamicum, effects of saline osmotic upshocks from 0.4 osnol. kg−1 to 2 osmol. kg−1 have been investigated on the growth kinetics and the intracellular content of the bacteria. Addition of a high concentration of NaCl after a few hours of batch culture results in a temporary interruption of the cellular growth. Cell growth resumes after about 1 h but at a specific rate that decreases with increasing medium osmolality. Investigation of the intracellular content showed, during the first 30 min following the shock, a rapid but transient influx of sodium ions. This was followed by a strong accumulation of proline, which rose from 5 to 110 mg/g dry weight at the end of the growth phase. A slight accumulation of intracellular glutamate from 60 to 75 mg/g dry weight was also observed. Accordingly, for Corynebacterium glutamicum an increased osmolality in the glutamate and proline synthesis during the growth phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    A rapid bactometer method for screening of biocides against sulfate-reducing bacteria (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 336-340 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A rapid and efficient bactometer method was developed for screening biocides against sulfate-reducing bacteria. The method is based on impedance microbiology principles and uses double-layer API (American Petroleum Institute) agar medium supplemented with 0.1% sodium thioglycolate as a reducing agent. Compared to the conventional API procedure, which requires 28 days, the present technique takes only 1 day to obtain test results. Excellent linear correlation (r=−0.98) was found between the impedance detection time and log initial cell concentration. The results of the bactometer test were comparable to that of the API bottle test.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172835
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Performance of a hybrid anaerobic reactor, combining a sludge blanket and a filter, treating slaughterhouse wastewater (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 351-357 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A column reactor, in which the bottom two-thirds were occupied by a sludge blanket and the upper one-third by submerged clay rings, was evaluated using slaughterhouse wastewater as substrate. The reactor was operated at 35°C at loading rates varying from 5 g to 45 g chemical oxygen demand (COD) 1−1 × day−1 at an influent concentration of 2450 mg COD 1−1. A maximum substrate removal rate of 32 g COD 1−1 × day−1, coupled with a methane production rate of 6.91 × 1−1 × day−1 (STP), was obtained. This removal rate is significantly higher than those previously reported. The rate of substrate utilization by the biomass was 1.22 g COD (g volatile suspended solids)−1 day−1. COD removal was over 96% with loading rates up to 25 g COD 1−1 × day−1, at higher loading rates performance decreased rapidly. It was found that the filter element of the reactor was highly efficient in retaining biomass, leading to a biomass accumulation yield coefficient of 0.029 g volatile suspended solids g−1 COD, higher than reported previously for either upflow anaerobic sludge-blanket reactors or anaerobic filters operating independently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172838
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Inorganic composition and microbial characteristics of methanogenic granular sludge grown in a thermophilic upflow anaerobic sludge blanket reactor (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 358-364 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract An upflow anaerobic sludge blanket reactor was operated under thermophilic conditions (55° C) for 160 days by feeding a wastewater containing sucrose as the major carbon source. The reactor exhibited a satisfactory performance due to the formation of well-settling granulated sludge, achieving a total organic carbon (TOC) removal of above 80% at an organic loading rate of 30 kg total organic C m−3 day−1. Structural and microbial properties of the methanogenic granular sludge were examined using scanning electron microscope X-ray analyses and serum vial activity tests. All the thermophilic granules developed showed a double-layered structure, comprised of a black core portion and a yellowish exterior portion. The interior cope portion contained abundant crystalline precipitates of calcium carbonate. Calcium-bound phosphorus was also present more prominently in the core portion than in the exterior portion. Methanogenic activities of the thermophilic granules both from acetate and from H2 increased with increasing vial-test temperature in the range of 55–65° C [from 1.43 to 2.36 kg CH4 chemical oxygen demand (COD) kg volatile suspended solids (VSS)−1 day−1 for acetate and from 0.85 to 1.11 kg CH4 COD kg VSS−1 day−1 for H2]. On the other hand, propionate-utilizing methanogenic activity was independent of vial-test temperature, and was much lower (0.1–0.12 kg CH4 COD kg VSS−1 day−1) than that from either acetate or H2. Acetate consumption during vial tests was considerably inhibited by the presence of H2 in the headspace, indicating that a syntrophic association between acetate oxidizers and H2-utilizing methane-producing bacteria was responsible for some portion of the overall acetate elimination by the theromophilically grown sludge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172839
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Biodegradation of 2-sulfonato fatty acid methyl ester (α-SFMe): Identification of microorganisms isolated from activated sludge and their capability for degrading α-SFMe (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 379-382 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Three bacterial strains, A, B and C, were isolated from activated sludge as 2-sulfonato-fatty-acid-methyl-ester (α-SFMe)-degrading microorganisms. From the results of morphological, physiological and biochemical studies, and analyses of 16S rRNA gene sequences, isolate A was identified as Agrobacterium tumefaciens while B and C were Pseudomonas putida, respectively. To demonstrate their capability for the ultimate biodegradation of α-SFMe, the degradation kinetics have been investigated using C14-α-SFMe and 2-14C-labeled C16-α-SFMe. The biodegradation was determined by measuring dissolved organic carbon (DOC) and released SO4 2−, in the shake-culture test, and evolved 14CO2 in the modified Organisation for Economic Co-operation and Development (OECD) test. In the shake culture test with C14-α-SFMe, DOC removal was progressive throughout the test. Liberation of inorganic sulfate started after DOC removal and then rapidly increased. During the 14CO2 evolution tests, the mineralization of radiolabeled carbon started quickly and reached about 80% of the initially added radioactivity at the end of the tests. The results obtained indicated that all of the isolates had the capability for ultimately degrading α-SFMe through the oxidation of the alkyl carbons and desulfonation (cleavage of the C-S linkage).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172843
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Effect of perfluorodecalin as an oxygen carrier on actinorhodin production by Streptomyces coelicolor A3(2) (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 206-210 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Perfluorodecalin, a perfluorocarbon (PFC), was used in this investigation as a dissolved oxygen carrier in the media of Streptomyces coelicolor cultures. The effects of different concentrations of PFC, PFC emulsified with pluronic F-68 and pluronic alone were investigated in the shake-flask cultures using both defined and complex media. In the defined medium with PFC alone, the maximum biomass and actinorhodin concentrations and the volumetric substrate consumption rates increased with increasing PFC concentration. They decreased dramatically, however, when the PFC concentration exceeded 50% (v/v). Emulsifying the PFC with pluronic F-68 resulted in a significant increase in antibiotic concentration while growth was unaffected. The inclusion of more than 4 g/l pluronic alone in the fermentation medium inhibited the growth. In the complex medium with 40% (v/v) PFC, although the final antibiotic concentration was unaffected, the onset of actinorhodin accumulation was 2 days earlier than that in the control. It was demonstrated that PFC and emulsified PFC did not have any deleterious effects on S. coelicolor cultures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050391
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Fed-batch biotransformation of β-ionone by Aspergillus niger (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 222-227 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Aspergillus niger IFO 8541 was found to be an efficient biocatalyst for the biotransformation of β-ionone into hydroxy and oxo derivatives. The reaction had to be carried out with an inoculum made of about 4×107 fresh spores/l and with a preliminary growth period giving at least 3 g/l biomass. The fungus developed in the form of pellets when cultivated as free mycelium; entrapment of the microorganism in calcium alginate beads was an efficient way to mimic this feature in an aerated, stirred bioreactor. The biotransformation was carried out using a fed-batch mode of operation involving sequential precursor addition. β-Ionone stopped the fungal growth and was converted into metabolites only when the carbon source remained present in the medium; it was fully oxidized after sucrose exhaustion. These conditions allowed recovery of about 2.5 g/l aroma compounds after 230 h cultivation with a molar yield close to 100%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050394
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Effect of perfluorodecalin as an oxygen carrier on actinorhodin production by Streptomyces coelicolor A3(2) (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 206-210 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Perfluorodecalin, a perfluorocarbon (PFC), was used in this investigation as a dissolved oxygen carrier in the media of Streptomyces coelicolor cultures. The effects of different concentrations of PFC, PFC emulsified with pluronic F-68 and pluronic alone were investigated in the shake-flask cultures using both defined and complex media. In the defined medium with PFC alone, the maximum biomass and actinorhodin concentrations and the volumetric substrate consumption rates increased with increasing PFC concentration. They decreased dramatically, however, when the PFC concentration exceeded 50% (v/v). Emulsifying the PFC with pluronic F-68 resulted in a significant increase in antibiotic concentration while growth was unaffected. The inclusion of more than 4 g/l pluronic alone in the fermentation medium inhibited the growth. In the complex medium with 40% (v/v) PFC, although the final antibiotic concentration was unaffected, the onset of actinorhodin accumulation was 2 days earlier than that in the control. It was demonstrated that PFC and emulsified PFC did not have any deleterious effects on S. coelicolor cultures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172813
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Lactic acid from cheese whey permeate. Productivity and economics of a continuous membrane bioreactor (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 242-248 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The economics of incorporating membrane modules in several steps in the conversion of whey permeate to lactic acid was studied. Membrane recycle fermenters operating at a cell concentration of 40 g l–1resulted in a productivity of 22.5 g l–1h–1with a lactate concentration of 89 g l–1 and a yield of 0.89. The membrane units (reverse osmosis for preconcentrating whey permeate, hollow-fiber ultrafiltration for clarification and for cell recycling) contribute about 28% of the total fixed capital costs and less than 5% of the operating cost. The two largest costs are whey transportation and yeast extract, contributing about 35% and 38% to the total product cost of US $ 0.98/kg 85% lactate. Without these two costs, unpurified lactate could be produced for $ 0.27/kg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050397
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Effect of agitation on growth and enzyme production of Trichoderma reesei in batch fermentation (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 249-258 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Growth, enzyme-producing activity and respiratory properties of Trichoderma reesei QM 9414 were examined under various agitation intensities. Two substrates were compared: lactose and Avicel. Pellet formation occurred at all agitation intensities for both substrates. Oxygen dependence at the lower agitation rate varied with the substrate type. With lactose as the carbon source, linear growth was observed, despite a regulation of the dissolved oxygen concentration at 30% saturation. The enzyme production was strongly affected by the agitation. At the higher agitation rates the enzyme production dropped. With Avicel as the carbon source, the production of enzymes surged as soon as the growth was limited by the hydrolysis of Avicel. Growth on Avicel, in the conditions we used, was limited by Avicel hydrolysis. Cubic growth was observed when lactose was the carbon source. A new derivation for a model of the observed cubic growth is proposed and is used to correlate growth, CO2 production and oxygen consumption in a consistent way, impossible with exponential growth models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Optimization of cellulase production by Penicillium occitanis (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 267-269 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The mutant Pol6 of Penicillium occitanis is an interesting strain for producing cellulases and hemicellulases. The nitrogen source and substrate that regulate cellulase production were evaluated in shake-flask and fermentor (batch and fed-batch) culture. The nature of the nitrogen source and the C/N ratio markedly affected cellulase production by P. occitanis. When nitrate was used in Mandels and Weber's basal growth medium with a C/N ratio below 20.2, it resulted in more cellulase production than from urea or ammonium sulphate. Crude substrates such as wheat bran and wheat flour residues, used in combination with a local cellulose esparto grass paper pulp as an alternative nitrogen source and cellulose substrates, also gave high cellulase yields. Greatest cellulase yields and productivity were obtained by fed-batch cultivation [23 filter-paper activity units (FPU)/ml and 168 FPUl–1h–1].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050400
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Purification and characterization of a lipase from Pichia burtonii (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 277-281 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  An extracellular lipase from Pichia burtonii was purified to homogeneity by a combination of DEAE-Sephadex A-50 ion-exchange chromatography, Sephadex G-100 gel filtration, and isoelectric focusing. The purified enzyme preparation showed a single protein band corresponding to a molecular mass of 51 kDa on sodium dodecyl sulphate/polyacrylamide gel electrophoresis. The molecular mass of the enzyme was estimated to be 47 kDa on Superdex 200 gel filtration, suggesting that the enzyme was a monomeric protein. The pI was about 5.8. The optimum pH and temperature for the hydrolysis of olive oil were about 6.5 and 45°  C respectively. Rapid loss of the enzyme activity was observed above 30°  C in the absence of olive oil, but the addition of olive oil or trimethylolpropane diallyl ether greatly stabilized the enzyme. At 30°  C, the enzyme hydrolysed Spans and Tweens as well as simple triglycerides of short- and middle-chain fatty acids. Although the enzyme cleaved all the ester bonds of triolein, it showed some preference for the outer ester bonds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Expression of cho and melC operons by a Streptococcus thermophilus synthetic promoter in Escherichia coli (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 285-290 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A 63-base-pair synthetic promoter, sP1, was synthesized on the basis of the nucleotide sequence of a putative Streptococcus thermophilus promoter. When inserted upstream from the Streptomyces cho operon in a recombinant plasmid, pUCO195P-36, sP1 activated the expression of the cho genes in Escherichia coli, as shown by the production of cholesterol oxidase by the transformants. The sP1-driven cholesterol oxidase production in pUCO195P-36-transformed cells was estimated to be 40% of that produced by P lac -mediated cho expression in a pUCO193-containing host. The recombinant pUCO195P-36 appeared to be segregationally less stable in E. coli DH5α than in HB101. Its non-expressing counterpart, pUCO195P-1, was stable in both E. coli strains. The activity of sP1 was further demonstrated in E. coli by the expression of a Streptomyces melC operon. When placed upstream from the test operon in the pMCU22aPa construct, sP1 activated the melC expression as shown by the production of tyrosinase at (3.0±0.3)×10–3 U/mg and (16.0±1.0)×10–3 U/mg protein equivalent of cell extract in the absence and presence of isopropyl β-d-thiogalactopyranoside, respectively. The presence of a counter-oriented P lac at the 3' end of the operon in the pMCU22bPa plasmid reduced the sP1-mediated tyrosinase production by about 85%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    celA, another gene coding for a multidomain cellulase from the extreme thermophile Caldocellum saccharolyticum (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 291-296 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Caldocellum saccharolyticum is an extremely thermophilic anaerobic bacterium capable of growth on cellulose and hemicellulose as sole carbon sources. Cellulase and hemicellulase genes have been found clustered together on its genome. The gene for one of the cellulases (celA) was isolated on a λ genomic library clone, sequenced and found to comprise a large open-reading frame of 5253 base pairs that could be translated into a peptide of 1751 amino acids. To date, it is the largest cellulase gene sequenced. The translated product is a multidomain structure composed of two catalytic domains and two cellulose-binding domains linked by proline-threonine-rich regions (PT linkers). The N-terminal domain of celA encodes for an endoglucanase activity on carboxymethylcellulose, consistent with its high homology to the sequences of several other endo-1,4-β-d-glucanases. The carboxylterminal domain shows sequence homology with a cellulase from Clostridium thermocellum (CelS), which is known to act synergistically with a second component to hydrolyze crystalline cellulose. In the absence of a Caldocellum homologue for this second protein, we can detect no activity from this domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Overproduction and purification of SulA fusion protein in Escherichia coli and its degradation by Lon protease in vitro (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 304-309 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  To overproduce extremely unstable SulA protein, which is the cell-division inhibitor of Escherichia coli, we fused the sulA gene to the maltose-binding protein (MBP) fusion vectors with or without the signal sequence (plasmids pMAL-p-SulA and pMAL-c-SulA respectively). The amount of the full-length fusion protein expressed from the plasmid pMAL-p-SulA (pre-MBP-SulA) in E. coli was much larger than that expressed from the plasmid pMAL-c-SulA (MBP-SulA). A major amount of the pre-MBP-SulA fusion protein was expressed in a soluble form and affinity-purified by amylose resin. Since site-specific cleavage of the fusion protein with factor Xa resulted in the precipitation of SulA protein, the pre-MBP-SulA fusion protein was used to study the degradation of SulA protein by E. coli Lon protease in vitro. It was found that only the SulA portion of the fusion protein was degraded by Lon protease in an ATP-dependent manner. This result provides direct evidence that Lon protease plays an important role in the rapid degradation of SulA protein in cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Sodium and proline accumulation in Corynebacterium glutamicum as a response to an osmotic saline upshock (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 315-320 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  In order to understand the role of the medium osmolality on the metabolism of glutamate-producing Corynebacterium glutamicum, the effects of saline osmotic upshocks from 0.4 osmol. kg–1 to 2 osmol. kg–1 have been investigated on the growth kinetics and the intracellular content of the bacteria. Addition of a high concentration of NaCl after a few hours of batch culture results in a temporary interruption of the cellular growth. Cell growth resumes after about 1 h but at a specific rate that decreases with increasing medium osmolality. Investigation of the intracellular content showed, during the first 30 min following the shock, a rapid but transient influx of sodium ions. This was followed by a strong accumulation of proline, which rose from 5 to 110 mg/g dry weight at the end of the growth phase. A slight accumulation of intracellular glutamate from 60 to 75 mg/g dry weight was also observed. Accordingly, for Corynebacterium glutamicum an increased osmolality in the culture medium resulted in a higher specific rate of glutamate and proline synthesis during the growth phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Diversity of anaerobic microbial processes in chlorobenzoate degradation: nitrate, iron, sulfate and carbonate as electron acceptors (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 929-936 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The utilization of monochlorobenzoate isomers (2-, 3- and 4-chlorobenzoate) by anaerobic microbial consortia in River Nile sediments was systematically evaluated under denitrifying, Fe-reducing, sulfidogenic and methanogenic conditions. Loss of all three chlorobenzoates was noted in denitrifying cultures; furthermore, the initial utilization of chlorobenzoates was fastest under denitrifying conditions. Loss of 3-chlorobenzoate was seen under all four reducing conditions and the degradation of chlorobenzoates was coupled stoichiometrically to NO- 3 loss, Fe2+ production, SO2- 4 loss or CH4 production, indicating that the chlorobenzoates were oxidized to CO2. To our knowledge, this is the first observation of halogenated aromatic degradation coupled to Fe reduction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050507
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Complete degradation of tetrachloroethene by combining anaerobic dechlorinating and aerobic methanotrophic enrichment cultures (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 920-928 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Degradation of tetrachloroethene (perchloroethylene, PCE) was investigated by combining the metabolic abilities of anaerobic bacteria, capable of reductive dechlorination of PCE, with those of aerobic methanotrophic bacteria, capable of co-metabolic degradation of the less-chlorinated ethenes formed by reductive dechlorination of PCE. Anaerobic communities reductively dechlorinating PCE, trichloroethene (TCE) and dichloroethenes were enriched from various sources. The maximum rates of dechlorination observed for various chloroethenes in these batch enrichments were: PCE to TCE (341 μmol l-1 day-1), TCE to cis-dichloroethene (159 μmol l-1 day-1), cis-dichloroethene to chloroethene (99 μmol l-1 day-1) and trans-dichloroethene to chloroethene (22 μmol l-1 day-1). A mixture of these enrichments was inoculated into an anoxic fixed-bed upflow column. In this column PCE was converted mainly into cis-1, 2-dichloroethene, small amounts of TCE and chloroethene, and chloride. Enrichments of aerobic methanotrophic bacteria were grown in an oxic fixed-bed downflow column. Less-chlorinated ethenes, formed in the anoxic column, were further metabolized in this oxic methanotrophic column. On the basis of analysis of chloride production and the disappearance of chlorinated ethenes it was demonstrated that complete degradation of PCE was possible by combining these two columns. Operation of the two-column system under various process conditions indicated that the sensitivity of the methanotrophic bacteria to chlorinated intermediates represented the bottle-neck in the sequential anoxic/oxic degradation process of PCE.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    A pressure test method monitors biofilm coated particle fluidization (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 383-386 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A fluidized bed denitrifying reactor was run to examine the vertical segregation of sand particles on the basis of different biofilm coverage, so far neglected when modelling fluidized beds. The segregation was found to be significant and it can be directly correlated with the vertical hydrostatic pressure profile in the bed. A procedure was developed for the rapid determination of biofilm thickness from hydrostatic pressure data using a recently published method based on the use of the novel criteria "expansion coefficient" and "specific occupied volume". A key feature of the procedure is the "particle content", which can be calculated from particle characteristics and is correlated in this study with the hydrostatic pressure gradient. The method was verified by directly measuring biofilm thickness as a function of the vertical position in the bed. This way biofilm thickness can be calculated from a readily measurable hydrostatic pressure profile with an error of 0.04 – 0.06 mm. This error is believed to be due to N2 gas entrapment in the denitrifying biofilm and to the original inaccuracy of the determination of particle size and volume. The method is rather insensitive to the exact biofilm density when the usual high-density carrier material is used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050422
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Increased coccolith production by Emiliania huxleyi cultures enriched with dissolved inorganic carbon (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 460-465 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Cells of Emiliania huxleyi grown on Eppley's medium enriched with dissolved inorganic carbon (DIC) developed multiple layers of coccoliths. The maximum diameter of cells grown in the presence of 13.2 mM DIC was 12.3 μm, whereas that of cells grown in the presence of 1.5 mM DIC was 8.0 μm. Although enrichment of Eppley's medium with DIC increased both coccolith production and cell growth, coccolith production was enhanced to a greater extent than cell growth. The enrichment of Eppley's medium with DIC was used to enhance production of coccolith particles by E. huxleyi. Repeated-batch culture, in which DIC, Ca2+, nitrate and phosphate concentrations in the medium were maintained by replacing the culture medium, was carried out in a closed photobioreactor. During repeated-batch culture, a maximum coccolith yield of 560 mg/l for 2 days and a maximum biomass yield of 810 mg/l for 2 days were achieved. Enrichment and maintenance of DIC is therefore an efficient method for the production of large quantities of coccoliths.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218449
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Glycerol fermentation by a new 1,3-propanediol-producing microorganism:Enterobacter agglomerans (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 786-793 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract According to their ability to synthesize 1,3-propanediol from glycerol, two species were isolated from the anoxic mud of a distillery waste-water digestor:Clostridium butyricum andEnterobacter agglomerans. The latter, a facultatively anaerobic gram-negative bacterium, is described for the first time as a microorganism producing 1,3-propanediol from glycerol. The products of glycerol conversion byE. agglomerans were identified using nuclear magnetic resonance. A 20-g/l glycerol solution was fermented mainly to 1,3-propanediol (0.51 mol/mol) and acetate (0.18 mol/mol). Ethanol, formate, lactate and succinate were formed as by-products. Gas production was very low; 1,3-propanediol production perfectly balanced the oxido-reduction state of the microorganism. Acetate was the predominant metabolite generating energy for growth. High-glycerol-concentration fermentations (71 g/l and 100 g/l) resulted in an increase of the 1,3-propanediol yield (0.61 mol/mol) at the expense of lactate and ethamol production. Specific rates of glycerol consumption and 1,3-propanediol and acetate production increased whereas the growth rate decreased. The decreased in ATP yield was linearly correlated with the specific rate of 1,3-propanediol production. Incomplete glycerol consumption (about 40 g/l) was systematically observed when high glycerol concentrations were used. The unbalanced oxido-reduction state, the low carbon recovery and the detection of an unknown compound by HPLC observed in these cases indicate the formation of another metabolite, which is possibly an inhibitory factor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02431909
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Relationship between molecular states (conformation and orientation) and activities of α-amylase adsorbed on ultrafine silica particles (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 801-807 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Bacillus subtilis α-amylase, which contains a relatively large amount of α-helix, was adsorbed on two types of ultrafine silica particles (silica-1 and-2, average diameter 15 nm) under various conditions. The changes in circular dichroism (CD) spectra of α-amylase upon adsorption were measured, and the extent of conformational changes was estimated from the reduction in α-helix content. In additions the activities of adsorbed α-amylase were measured at pH 5.2 using corn starch andp-nitrophenylbenzyl α-maltopentaoside (BG5P). In the ultrafine silica-2 particles, the extent of both activity reductions and conformational changes upon adsorption was much larger than that in the ultrafine silica-1 particles and increased with decreasing pH and amount of adsorption. The extent of activity reductions correlated closely with the conformational changes. On the other hand, the effect of reduction in α-amylase activity upon adsorption measured by BG5P was smaller than that measured by starch, indicating that the lack of accessibility of the active site to a large substrate also reduces the activity of adsorbed α-amylase. However, the effects of particle type and adsorption conditions on the extent of activity reductions by the accessibility resistance were small. Therefore, variation of the activity of adsorbed α-amylase is mainly attributable to the extent of conformational changes upon adsorption. Based on these results, a procedure to prepare adsorbed α-amylase with high activity was investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02431911
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Liquid-culture pH, temperature, and carbon (not nitrogen) source regulate phenazine productivity of the take-all biocontrol agentPseudomonas fluorescens 2-79 (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 794-800 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Strain 2-79 is a biocontrol agent against take-all, an important disease of wheat caused byGaeumannomyces graminis var.tritici. In the rhizosphere, it produces the antibiotic phenazine 1-carboxylic acid (PCA) as the primary means of disease suppression. One barrier to commercial use of phenazine-producing pseudomonads, like strain 2–79, is the lack of liquid-culture technology for mass production. For instance, there is little published research concerning the impact of liquid-culture secondary metabolism on the biocontrol qulaities of the cell harvest, i.e., efficacy, phytotoxicity, and storage survival. Yet it is important to know whether the fermentation process should be designed to enhance or eliminate secondary metabolite accumulation. To enable future exploration of this issue, we identified liquid-culture parameters that could be manipulated to control the phenazine productivity of strain 2–79. Our results indicated that PCA accumulation was very sensitive to the culture pH and temperature. It was possible to produce large cell populations with either high or low phenazine productivity by choosing to control culture pH at 7 and 8 respectively. Although high cell accumulations were achieved over the broad 25–34°C range studied, high, moderate, or low PCA productivities were observed at 25–27°C, 29–32.5°C, or 34°C respectively. When pH was controlled at 7, specific PCA productions at 25°C could be modulated by the choice of carbon source supplied. PCA accumulation per unit biomass reached 0.31 g/g on glucose, 0.16 g/g on glycerol and xylose, and only 0.09 g/g on fructose. Although the nitrogen source was also tested as a variable, it had little influence on culture PCA productivity under controlled pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02431910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Production of ethanol at 45°C on starch-containing media by mixed cultures of the thermotolerant, ethanol-producing yeast Kluyveromyces marxianus IMB3 and the thermophilic filamentous fungus Talaromyces emersonii CBS 814.70 (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 408-411 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The thermotolerant, ethanol-producing yeast strain, Kluyveromyces marxianus IMB3, was shown to produce ethanol at 45°C on starch-containing media supplemented with a crude amylase preparation derived from the thermophilic, filamentous fungus Talaromyces emersonii CBS 813.70. Ethanol production on media containing 4% (w/v) starch increased to a maximum of 15 g/l with 40 h, and this represented 74% of the maximum theoretical yield. Subsequent experimentation involving growth of both organisms in fermentations on starch-containing media (4% w/v) demonstrated that the mixed-culture system was capable of ethanol production at 45°C with maximum yields at 12 g/l obtained with 65 h. The advantages associated with ethanol production by this system are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050426
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Study of a single and mixed culture for the direct bio-conversion of sorghum carbohydrates to ethanol (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 412-415 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Fusarium oxysporum F3 alone or in mixed culture with Saccharomyces cerevisiae 2541 fermented soluble and insoluble carbohydrates of sweet sorghum stalk directly to ethanol. Both microorganisms were first grown aerobically and fermented sorghum stalk to ethanol thereafter. During fermentation, insoluble carbohydrates were hydrolysed to soluble sugars by the celluloytic system of F. oxysporum. Ethanol yields as high as 24.4 and 33.5 g/100 g dry stalks were obtained by F. oxysporum and the mixed culture respectively, representing a theoretical yield enhancement of 11.6% and 53.6% respectively. The corresponding ethanol concentrations in the fermentation medium were 4.6% and 6.4% (w/v). These results clearly demonstrated that a large portion of insoluble carbohydrate from sorghum was converted by simultaneous saccharification and fermentation to ethanol, making the process promising for bioethanol production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050427
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Production of anthraquinones by immobilized Frangula alnus Mill. plant cells in a four-phase air-lift bioreactor (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 416-423 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The production of anthraquinones by Frangula alnus Mill. plant cells was used as a model system to evaluate the performance of a liquid-liquid extractive product-recovery process. The shake flask experiments have shown higher production of anthraquinones in cell suspension and flask cultures of calcium-alginate-immobilized cells when silicone oil was incorporated into the medium, compared to a control without silicone oil. An external-loop air-lift bioreactor, developed and designed for the production and simultaneous extraction of extracellular plant cell products, was regarded as a four-phase system, with dispersed gas, non-aqueous solvent and calcium-alginate-immobilized plant cells in Murashige and Skoog medium. Continuous extraction of anthraquinones by silicone oil and n-hexadecane inside the bioreactor resulted in 10–30 times higher cell productivity, compared to that of immobilized cells in a flask. Based on the mixing pattern, immobilized biocatalyst extraparticle and intraparticle diffusional constraints and the kinetics of growth, substrate consumption and product formation, a mathematical model was developed to describe the time course of a batch plant cell culture. The model showed satisfactory agreement with four sets of shake flask experiments and three bioreactor production cycles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050428
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Experimental and theoretical investigations of submerged fermentation and synthesis of pectinolytic enzymes by Aspergillus niger (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 424-430 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The growth of the microorganism and the production of the pectinolytic enzyme complex in a stirred 30-l biofermentor using the Aspergillus niger Rehbrücke strain were studied. The time courses of fermentation parameters (formation of biomass, consumption of carbon and inorganic nitrogen source, formation of pectinolytic enzymes) were measured. The formation of biomass showed a distinct lag phase, followed by a log phase with exponential growth and finally a stationary period when cell lysis was beginning. The uptake of the carbon source and inorganic nitrogen source by the A. niger cells corresponded to the time course of growth. The formation of pectinolytic enzymes took place in two steps. The first one was growth-bounded and finished with the end of the log phase of biomass growth. The second step of pectinolytic enzyme formation took place after the end of the catabolite repression of the carbon source and was not growth-bounded. On the basis of the experimental data a mathematical model of the fermentation process was developed. Comparison of the kinetics of the measured fermentation curves and the solution curves of the model showed qualitatively good agreement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050429
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    3-Methylaspartate ammonia-lyase from a facultative anaerobe, strain YG-1002 (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 901-907 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract 3-Methylaspartase was purified 24-fold and crystallized from the crude extract of the cells of a facultative anaerobic bacterium from soil, strain YG-1002. The molecular mass of the native enzyme was about 84 kDa and that of the subunit was about 42 kDa. The pH optimum for the deamination reaction of (2S, 3S)-3-methylaspartic acid and those for the amination reaction of mesaconic acid were 9.7 and 8.5; its optimum temperature was 50°C. The enzyme was stable at pH 5.5–11.0 and up to 50°C. The enzyme required both divalent and monovalent cations such as Mg2+ and K+. The enzyme was inhibited by sulfhydryl reagents, metal-chelating reagents and some divalent cations. The enzyme catalyzed the reversible amination/deamination reactions between several 3-substituted (S)-aspartic acids and their corresponding fumaric acid derivatives. The enzyme preferentially acted on (2S, 3S)-3-methylaspartic acid and mesaconic acid in the deamination and the amination reactions respectively. The enzyme showed high similarities in several enzymological properties and N-terminal amino acid sequence with 3-methylaspartase from an obligate anaerobic bacteriumClostridium tetanomorphum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02431926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Effect of oxygen and carbon dioxide on germination and growth ofRhizopus oligosporus on model media and soya beans (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 908-913 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The microcolony technique enables the effects of several atmospheric conditions on fungal growth to be studied by measuring the radius of the colony, while excluding effects of those conditions on germination of the sporangiospores. Various concentrations of oxygen and carbon dioxide in the gas environment were found to influence growth ofRhizopus oligosporus on malt extract/soya peptone/agar. The maximum radial growth rate was 1.48 mm/h and the maximum specific growth rate was 0.109 h−1 at 30°C. Oxygen became limiting below 1% (v/v), but growth remained possible at levels of 0.001% oxygen. Carbon dioxide stimulated growth at limiting oxygen levels. The specific growth rate increased from 0.043 h−1 at 0.5% (v/v) oxygen and 0% (v/v) carbon dioxide to 0.096 h−1 at 0.5% (v/v) oxygen and 5% (v/v) carbon dioxide. A mixture of 0.5% (v/v) oxygen and 35% (v/v) carbon dioxide inhibited growth. Delay of sporangiospore germination due to low (less than 0.001%) amounts of oxygen was not observed with the techniques used. Fungal activity in a rotating drum fermentor was more strongly affected by low levels of oxygen than was biomass formation on model media. High concentrations of carbon dioxide inhibited growth in the rotating drum fermentor at non-limiting levels of oxygen. It is concluded that aeration and heat removal are both essential aspects of optimization of large-scale solid-substrate bioreactors withRh. oligosporus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02431927
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Biocalorimetry-supported analysis of fermentation processes (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 431-439 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The close relation between metabolic activity and heat release means that calorimetry can be successfully applied for on-line monitoring of biological processes. Since the use of available calorimeters in biotechnology is difficult because of technical limitations, a new sensitive heat-flux calorimeter working as a laboratory fermenter was developed and tested for different aerobic and anaerobic fermentations with Saccharomyces cerevisiae and Zymommonas mobilis. The aim of the experiments was to demonstrate the abilities of the method for biotechnological purposes. Fermentations as well as the corresponding heat, substrate and product analyses were reproducible. During experiments the heat signal was used as a sensitive and fast indicator for the response of the organisms to changing conditions. One topic was the monitoring of diauxic growth phenomena during batch fermentations, which may affect process productivity. S. cerevisiae was used as the test organism and a protease-excreting Bacillus licheniformis strain as an industrial production system. Other experiments focused on heat measurements in continuous culture under substrate-limiting conditions in order to analyse bacterial nutrient requirements. Again, Z. mobilis was used as the test organism. Ammonium, phosphate, magnesium, biotin and panthothenate, as important substrate compounds, were varied. The results indicate that these nutrients are required in lower amounts for growth than formerly suggested. Thus, a combination of heat measurements and other methods may rapidly improve our knowledge of nutrient requirements even for a well-known microorganism like Z. mobilis. *** DIRECT SUPPORT *** AG903062 00004
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218445
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    The importance of bead size measurement in mass-transfer modelling with immobilised cells (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 440-444 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effective diffusivity of O2 inside immobilised cell particles has been much discussed. Most reported estimates are based on fitting a mass-transfer reaction model to measured total oxygen uptake rates. The particle diameter has the largest single influence in such models, but its accurate measurement has probably recieved insufficient attention. We have studied sorbitol and glucose oxidation by cells of Gluconobacter suboxydans entrapped in calcium alginate gel beads. These beads were found to shrink rapidly in air, so that size measurement under water is essential. By comparison with rigid particles of similar known size, it was shown that measurement of the microscopic image gives a systematic underestimate. In consequence, the fitted oxygen diffusivity will be around 20% too low. Careful attention to size measurement gave good agreement between diffusivity estimates from beads with different mean sizes and cell loadings, with a best value of 2.51 × 109 m2s−1, 92% of the value for pure water. The estimated diffusivity is not significantly affected by a distribution of bead sizes with up to 10% standard deviation about the same mean.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218446
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Production of 3,4-dihydroxyphthalate from phthalate by a membrane-bound two-enzyme system from Rhodococcus erythropolis (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 470-472 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Gram-positive Rhodococcus erythropolis strain S1 formed enzymes for the degradation of phthalate when grown in a phthalate-containing minimal medium. The membrane fraction prepared from phthalate-grown cells by ultrasonication converted phthalate to protocatechuate as the final product. Using two membrane-bound enzymes, phthalate 3,4-dioxygenase (PO) and 3,4-dihydro-3,4-dihydroxyphthalate 3,4-dehydrogenase (PH), prepared by solubilization of the membrane fraction, 3,4-dihydroxyphthalate was selectively obtained from phthalata. Fe2+ and Mn2+ stimulated the formation of 3,4-dihydroxyphthalate by the membrane-bound PO and PH system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050436
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Purification and properties of an alkaline protease from alkalophilic Bacillus sp. KSM-K16 (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 473-481 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Alkaline protease (EC 3.4.21.14) activity, suitable for use in detergents, was detected in the alkaline culture medium of Bacillus sp. KSM-K16, which was originally isolated from soil. The enzyme, designated M protease, was purified to homogeneity from the culture broth by column chromatographies. The N-terminal amino acid sequence was Ala–Gln–Ser–Val–Pro–Trp–Gly–Ile–Ser–Arg–Val–Gln–Ala–Pro–Ala–Ala–His–Asn–Arg–Gly–Leu–Thr–Gly. The molecular mass of the protease was 28 kDa, and its isoelectric point was close to pH 10.6. Maximum activity toward casein was observed at 55 °C and at pH 12.3 in 50 mM phosphate/NaOH buffer. The activity was inhibited by phenylmethylsulfonyl fluoride and chymostatin. The enzyme was very stable in long-term incubation with liquid detergents at 40 °C. The enzyme cleaved the oxidized insulin B chain initially at Leu15–Tyr16 and efficiently at ten more sites. Among various oligopeptidyl p-nitro-anilides (pNA) tested, N-succinyl-Ala-Ala-Pro-Phe-pNA was efficiently hydrolyzed by M protease. M protease was precipitated in (NH4)2SO4-saturated acetate buffer (pH 5.0) as plank-like crystals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050437
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Production of isoleucine by overexpression of ilvAin a Corynebacterium lactofermentum threonine producer (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 482-488 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Overproduction of isoleucine, an essential amino acid, was achieved by amplification of the gene encoding threonine dehydratase, the first enzyme in the threonine to isoleucine pathway, in a Corynebacterium lactofermentum threonine producer. Threonine overproduction was previously achieved with C. lactofermentum ATCC 21799, a lysine-hyperproducing strain, by introduction of plasmid pGC42 containing the Corynebacterium hom dr and thrB genes (encoding homoserine dehydrogenase and homoserine kinase respectively) under separate promoters. The pGC42 derivative, pGC77, also contains ilvA, which encodes threonine dehydratase. In a shake-flask fermentation, strain 21799(pGC77) produced 15  g/l isoleucine, along with small amounts of lysine and glycine. A molar carbon balance indicates that most of the carbon previously converted to threonine, lysine, glycine and isoleucine was incorporated into isoleucine by the new strain. Thus, in our system, simple overexpression of wild-type ilvA sufficed to overcome the effects of feedback inhibition of threonine dehydratase by the end-product, isoleucine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050438
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Monitoring transport of a recombinant phosphotriesterase in Streptomyces lividans using a pulse-chase system (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 493-497 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  A heterologous phosphotriesterase (parathion hydrolase) was previously shown to be secreted by Streptomyces lividans. To investigate the mechanism of secretion, a system to label the protein and follow its expression and secretion was developed. The recombinant S. lividans was grown first in a defined medium containing [35S]methionine that permitted expression but not secretion. It was then transferred to tryptone/glucose medium with unlabeled methionine for the chase period, during which secretion was observed. The results indicate a relatively slow rate of secretion that is also dependent on the growth medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050440
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    A novel promoter, derived from the isocitrate lyase gene of Candida tropicalis, inducible with acetate in Saccharomyces cerevisiae (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 489-492 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  When the isocitrate lyase gene, containing 5′-upstream and 3′-flanking regions, of an n-alkane-assimilating yeast Candida tropicalis was introduced into Saccharomyces cerevisiae, the enzyme was functionally overexpressed in the cells grown on acetate. The amount of the recombinant isocitrate lyase expressed in S. cerevisiae was as much as 30% of the total soluble proteins in the cells, being comparable to that with GAL7 functional under the control of galactose. The expression was also observed when the cells were grown on glycerol, lactate, ethanol or oleate. These facts indicate that the isocitrate lyase gene upstream region (UPR-ICL) contains a strong promoter functional in S. cerevisiae. UPR-ICL is active as a promoter on cheap carbon sources such as acetate and non-conventional carbon sources such as oleate, whereas many conventional strong promoters demand relatively expensive sugars or sugar derivatives. Therefore, it is promising to construct an economical recombinant protein production system by using UPR-ICL.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050439
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    A target-specific chimeric toxin composed of epidermal growth factor and Pseudomonas exotoxin A with a deletion in its toxin-binding domain (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 498-507 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  We have fused the epidermal growth factor (EGF) to the amino terminus of Pseudomonas exotoxin A (PE) to create a cytotoxic agent, designated EGF-PE, which preferentially kills EGF-receptor-bearing cells. In this study, we analyzed the effect of the Ia domain, the binding domain, of PE on the cytotoxicity of EGF-PE towards EGF-receptor-bearing cells and tried to develop a more potent EGF-receptor-targeting toxin. EGF-PE molecules with sequential deletions at the amino terminus of PE were constructed and expressed in E. coli strain BL21(DE3). The cytotoxicity of these chimeric toxins was then examined. Our results show that the amino-terminal and carboxy-terminal regions of the Ia domain of PE are important for the cytotoxicity of a PE-based targeting toxin. To design a more potent PE-based EGF-receptor-targeting toxin, a chimeric toxin, named EGF-PE(Δ34–220), which had most of the Ia domain deleted but retained amino acid residues 1–33 and 221–252 of this domain, was constructed. EGF-PE(Δ34–220) has EGF-receptor-binding activity but does not show PE-receptor-binding activity and is mildly cytotoxic to EGF-receptor-deficient NR6 cells. As expected, EGF-PE(Δ34–220) is a more potent cytotoxic agent towards EGF-receptor-bearing cells than EGF-PE(Δ1–252), where the entire Ia domain of PE was deleted. In addition, EGF-PE(Δ34–220) was shown to be extremely cytotoxic to EGF-receptor-bearing cancer cells, such as A431, CE81T/VGH, and KB-3-1 cells. We also found that EGF-PE(Δ34–220) was highly expressed in BL21(DE3) and could be easily purified by urea extraction. Thus, EGF-PE(Δ34–220) can be a useful cytotoxic agent towards EGF-receptor-bearing cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050441
    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...