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  • 1
    Electronic Resource
    Electronic Resource
    Enzymatic interesterification of triglyceride with surfactant-coated lipase in organic media (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 45 (1995), S. 27-32 
    Details
    ISSN: 0006-3592
    Keywords: esterification ; lipase ; glycerides ; organic solvent ; surfactant ; bioconversion ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Several surfactant-coated enzymes have been prepared by coating lipases of various origins with a nonionic surfactant, glutamic acid dioleylester ribitol (2C18Δ9GE). Enzymatic interesterification of tripalmitin with oleic acid using the surfactant-coated lipase was carried out in organic media. The surfactant-coated lipases could effectively catalyze the interesterification of glycerides better than did the powder lipases. A suitable organic solvent was an aliphatic hydrocarbon such as isooctane. The enzymatic activity for the interesterification strongly depended on the origin of the lipase. The surfactant-coated lipase prepared by Mucor javanicus showed the highest enzymatic activity for the interesterification of glycerides, although its powder lipase did not show enzymatic activity. Selective interesterification of glycerides could be performed by adjusting the concentration ratio of oleic acid to tripalmitin in isooctane. Di-substituted glyceride could be selectively produced when the concentration ratio of carboxylic acid to glycerides was 7. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260450105
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  • 2
    Electronic Resource
    Electronic Resource
    Trickle-bed reactor performance. Part I. Holdup and mass transfer effects (1975)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 21 (1975), S. 706-713 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Liquid holdup and mass transfer rates were measured in a 2.58-cm I.D. tube, packed with glass beads and granular CuO · ZnO catalyst or β-naphthol particles, and operated as a trickle bed. Gas-to-liquid (water) transport coefficients were determined from absorption and desorption experiments with oxygen at 25°C and 1 atm. Liquid-to-particle mass transfer was studied using β-naphthol particles.Holdup and both mass transfer coefficients were unaffected by gas flow rate but increased with liquid rate. The data were correlated with equations that could be used for predicting mass transfer coefficients at high temperatures and pressures for use in the reaction studies reported in Part II.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690210410
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  • 3
    Electronic Resource
    Electronic Resource
    Performance of slurry and trickle-bed reactors: Application to sulfur dioxide removal (1978)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 24 (1978), S. 286-293 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Methods are developed for predicting the performance of different types of three-phase reactors for removal of a gaseous reactant by catalytic reaction. The removal is assumed to occur by mass transport of reactant from gas-to-liquid and liquid-to-catalyst particle and then by intraparticle diffusion and reaction in the liquid filled pores. The method is applied to the oxidation of sulfur dioxide at 25°C and 1 atm using activated carbon, in the presence of water, as a catalyst. Slurry, trickle-bed, and counterflow packed-bed reactors are compared in terms of the key variables affecting the fraction of sulfur dioxide reacted.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690240218
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  • 4
    Electronic Resource
    Electronic Resource
    Analysis of three-phase packed-bed reactors (1978)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 24 (1978), S. 294-302 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Three-phase reactors involving a solid catalyst are normally used for production of product or removal of impurity. Equations are presented for these two measures of reactor performance for a first-order, reversible or irreversible reaction in an isothermal reactor. The results are presented in terms of dimensionless groups of the pertinent mass transfer, kinetic, and equilibrium (solubility) properties, and the gas and liquid flow rates. From the equations given, it is possible to predict the relative performance of concurrent (trickle bed) and countercurrent flow reactors and also the effect of mixing in the gas or liquid streams on performance.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690240219
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  • 5
    Electronic Resource
    Electronic Resource
    Trickle-bed reactor performance. Part II. Reaction studies (1975)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 21 (1975), S. 714-720 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Dilute solutions (132 ppm) of formic acid in water were oxidized with air in a trickle-bed reactor at 212° to 240°C and 40 atm. Particles 0.291 and 0.0541 cm in diameter, prepared from a commercial CuO · ZnO catalyst, were used to provide a model system for studying water purification by catalytic oxidation.Differential reactor runs were made to measure the global rate of reaction. These data were compared with predicted rates from the known intrinsic kinetics and intraparticle diffusivities, and the mass transfer coefficients measured in Part I.High conversion (of formic acid) data were also obtained in order to test models for trickle-bed reactors. Experimental conversions agreed reasonably well (within 10%) with predicted values based upon intrinsic kinetics and the several transport rates. Axial dispersion was found to be less important than gas-to-liquid mass transfer and intraparticle diffusion. In our laboratory studies (reactor I.D. = 1 in.) careful arrangements were made to obtain nearly uniform distribution of liquid over the reactor cross section. Hence effects of maldistribution, which may be important in large-scale reactors, were minimized.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690210411
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  • 6
    Electronic Resource
    Electronic Resource
    Lipase catalyzed transesterification of 2-substituted 3-hydroxy esters (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 10 (1998), S. 693-698 
    Details
    ISSN: 0899-0042
    Keywords: Pseudomonas cepacia ; lipase PS ; transesterification ; kinetic resolution ; 2-substituted 3-hydroxy ester ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetic resolution of 2-substituted 3-hydroxy esters was examined by lipase PS catalyzed transesterification using vinyl acetate as an acyl donor. Resolution of (±)-syn- and -anti-1a, -1e possessing a small methyl group at the C-3 position was accomplished enantioselectively. The outcome of the resolution seems to be related to the differences in size of the substituents at the stereocenter bearing a secondary hydroxy group. Chirality 10:693-698, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Protein refolding by reversed micelles utilizing solid-liquid extraction technique (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 57 (1998), S. 620-623 
    Details
    ISSN: 0006-3592
    Keywords: protein refolding ; reversed micelles ; solid-liquid extraction ; RNase A ; DNA ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article reports that a reversed micellar solution is useful for refolding proteins directly from a solid source. The solubilization of denatured RNase A, which had been prepared by reprecipitation from the denaturant protein solution, into reversed micelles formulated with sodium di-2-ethylhexyl sulfosuccinate (AOT) has been investigated by a solid-liquid extraction system. This method is an alternative to the ordinary protein extraction in reversed micelles based on the liquid-liquid extraction. The solid-liquid extraction method was found to facilitate the solubilization of denatured proteins more efficiently in the reversed micellar media than the ordinary phase transfer method of liquid extraction. The refolding of denatured RNase A entrapped in reversed micelles was attained by adding a redox reagent (reduced and oxidized glutathion). Enzymatic activity of RNase A was gradually recovered with time in the reversed micelles. The denatured RNase A was completely refolded within 30 h. In addition, the efficiency of protein refolding was enhanced when reversed micelles were applied to denatured RNase A containing a higher protein concentration that, in the case of aqueous media, would lead to protein aggregation. The solid-liquid extraction technique using reversed micelles affords better scale-up advantages in the direct refolding process of insoluble protein aggregates. ©1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 620-623, 1998.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Ionic graft copolymerization. II. Graft copolymerization of β-propiolactone onto acrylonitrile-sodium acrylate copolymer (1967)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 773-790 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polyacrylonitrile-β-propiolactone (βPL) graft copolymer was synthesized by means of ionic polymerization, in which polymerization of βPL was initiated by polyacrylonitrile containing a small amount of some reactive groups such as —COOK, —COONa, —COOLi, and —COOH. Lower electronegativity of the countercation favored higher total conversion and higher grafting percentage. The grafting percentage increased with the reaction time and concentration of reactive groups in the trunk polymer, but grafting efficiency varied very little under these conditions. In the bulk polymerization at 60°C., grafting efficiency was about 60%, but in the solution polymerization in toluene or dioxane, grafting efficiency was higher than in bulk or nitrobenzene.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1967.070110602
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  • 9
    Electronic Resource
    Electronic Resource
    Design of surfactants suitable for protein extraction by reversed micelles (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 54 (1997), S. 26-32 
    Details
    ISSN: 0006-3592
    Keywords: reversed micelle ; microemulsion ; protein extraction ; surfactant ; bioseparation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: New surfactants have been synthesized for potential use in reversed micellar protein extraction operations. Preferential solubility of the surfactant in an aliphatic solvent such as hexane, heptane, or isooctane and the formation of reversed micelles accompanied with solubilization of significant quantities of water can be achieved by using strongly hydrophobic, twin alkyl chains as the hydrophobic moiety. Different surfactants having identical water-solubilizing capacities can have significantly different behavior in protein extractions, where extraction efficiency appears to be governed by the nature of the interfacial complex that forms between surfactants and proteins. Bulky surfactant chains provide a steric hindrance to the adsorption of the surfactant to the protein surface, thus inhibiting solvation of the protein/surfactant complex, and hence protein extraction. Under these conditions, a precipitate forms either in the bulk aqueous phase or at the interface. Surfactants that can form a close-packed complex with the protein are excellent protein-solubilizing agents. Dioleyl phosphoric acid (DOLPA) appears to be the best surfactant currently available for protein extraction. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 26-32, 1997.
    Additional Material: 9 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Novel preparation method for surfactant-lipase complexes utilizing water in oil emulsions (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 55 (1997), S. 455-460 
    Details
    ISSN: 0006-3592
    Keywords: enzyme ; biocatalyst ; lipase ; organic solvent ; emulsion ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel preparation method for surfactant-lipase complexes has been developed utilizing water in oil emulsions. In order to optimize the preparation conditions, we have investigated the effects of several operational parameters on the enzymatic activity of the surfactant-lipase complexes in organic media. When a nonionic surfactant was employed under optimal preparation conditions [alkaline pH 8-10, organic/aqueous = 90/10 (v/v), concentration of surfactant, 10 mM[, the surfactant-lipase complex efficiently catalyzed the esterification of benzyl alcohol with lauric acid in organic media. The esterification rate of the surfactant-lipase complex was increased over 16-fold relative to the native powder lipase. Furthermore, the lipase complex showed high storage stability. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 455-460, 1997.
    Additional Material: 4 Ill.
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