Journal ArticleDOI
Efficient immobilization of lipases by entrapment in hydrophobic sol-gel materials.
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TLDR
A novel method to achieve lipase immobilization by entrapment in chemically inert hydrophobic silica gels which are prepared by hydrolysis of alkyl‐substituted silanes in the presence of the enzyme is presented.Abstract:
The commercial application of lipases as biocatalysts for organic synthesis requires simple but efficient methods to immobilize the enzyme, yielding highly stable and active biocatalysts which are easy to recover. In this study, we present a novel method to achieve lipase immobilization by entrapment in chemically inert hydrophobic silica gels which are prepared by hydrolysis of alkyl-substituted silanes in the presence of the enzyme. A typical immobilization procedure uses: an aqueous solution of lipase; sodium fluoride as a catalyst; and additives like polyvinyl alcohol or proteins and alkoxysilane derivatives like RSi-(OMe)3 with R = alkyl, aryl, or alkoxy as gel precursors. The effect of various immobilization parameters like stoichiometric ratio of water, silane, type and amount of additive, type and amount of catalyst, and type of silane has been carefully studied. The new method is applicable for a wide variety of lipases, yielding immobilized lipases with esterification activities enhanced by a factor of up to 88, compared to the commercial enzyme powders under identical conditions. Studies on the stability of sol-gel immobilized lipases under reaction conditions or storage (dry, in aqueous or organic medium) revealed an excellent retention of enzymatic activity. The possible reasons for the increased enzyme activities are discussed. © 1996 John Wiley & Sons, Inc.read more
Citations
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Journal ArticleDOI
Production, purification, characterization, and applications of lipases.
TL;DR: The production, recovery, and use of microbial lipases are discussed; issues of enzyme kinetics, thermostability, and bioactivity are addressed; and production of recombinant lipases is detailed.
Journal ArticleDOI
Potential of Different Enzyme Immobilization Strategies to Improve Enzyme Performance
TL;DR: The advantages and disadvantages of the different existing immobilization strategies to solve the different aforementioned enzyme limitations are given and some advice to select the optimal strategy for each particular enzyme and process is given.
Journal ArticleDOI
Microencapsulation: industrial appraisal of existing technologies and trends
TL;DR: In this paper, a timely and targeted release of food ingredients at the right place and the right time is provided by microencapsulation, which can improve the effectiveness of food additives, broaden the application range of ingredients and ensure optimal dosage, thereby improving cost effectiveness for the food manufacturer.
Journal ArticleDOI
Silica aerogel; synthesis, properties and characterization
TL;DR: In this article, a review of research work and developments in synthesis, properties and characterization of silica aerogels is presented, with particular attention paid to drying, which is a critical step in aerogel synthesis and makes the production of this material more economical and commercial.
Journal ArticleDOI
Microbial lipases form versatile tools for biotechnology
TL;DR: Immobilization in hydrophobic sol-gel matrices and in vitro evolution are promising novel approaches to increasing the stability or enantioselectivity, respectively, of lipases.
References
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Journal ArticleDOI
Controlled growth of monodisperse silica spheres in the micron size range
TL;DR: In this article, a system of chemical reactions has been developed which permits the controlled growth of spherical silica particles of uniform size by means of hydrolysis of alkyl silicates and subsequent condensation of silicic acid in alcoholic solutions.
Journal ArticleDOI
A model for interfacial activation in lipases from the structure of a fungal lipase-inhibitor complex
Andrzej M. Brzozowski,Andrzej M. Brzozowski,Urszula Derewenda,Urszula Derewenda,Zygmunt S. Derewenda,Zygmunt S. Derewenda,Guy Dodson,David M. R. Lawson,Johan P. Turkenburg,Fredrik Björkling,B. Huge-Jensen,S. A. Patkar,L. Thim +12 more
TL;DR: It is proposed that the structure of the enzyme in this complex of R. miehei lipase with n-hexylphosphonate ethyl ester is equivalent to the activated state generated by the oil–water interface.
Journal ArticleDOI
Enzymes and Other Proteins Entrapped in Sol-Gel Materials
Journal ArticleDOI
Action de la lipase pancréatique sur les esters en émulsion
L. Sarda,P. Desnuelle +1 more
TL;DR: De considerer la lipase pancreatique comme une esterase particuliere destinee a agir sur des esters insolubles au niveau of l'interface separant ces esters de l'eau, un calcul fait intervenir the “concentration molaire interfaciale” du substrat.