ZOLTÁN BOROS^1,2, EMESE ABAHÁZIOVÁ¹, MÁRK OLÁH1, PÉTER SÁTORHELYI³, BALÁZS ERDÉLYI³, LÁSZLÓ POPPE^1,2,*
*Corresponding author
1. Budapest University of Technology and Economics, Department of Organic Chemistry and Technology, Muegyetem rkp. 3, Budapest, H-1111, Hungary
2. SynBiocat Ltd., Lázár deák u. 4/1, Budapest, H-1173, Hungary3. Fermentia Microbiological Ltd., Berlini út 47-49, Budapest, H-1045, Hungary

Abstract

A series of eighteen novel surface modified silica gels were systematically studied as carriers of lipase A and B from Candida antarctica (CaLA and CaLB) by using hydrophobic adsorption methodology. Many of the mechanically stable novel hydrophobic silica gels were found as efficient lipase carriers resulting in new biocatalysts with different degrees of activity and enantioselectivity. Selective adsorption preferring CaLB from the mixture of the two lipases onto the novel supports indicated that proper hydrophobic adsorbents can offer us a simple, efficient and low-cost technology to separate useful lipases from their mixture or even from a crude extract. The usefulness of the methodology was demonstrated by production of a selective lipase from Pseudozyma aphidis (PaL) as immobilized biocatalyst directly from the fermentation supernatant in a single step.

INTRODUCTION

Enzymes are versatile catalysts in many industrial applications (1, 2). In spite of their enormous synthetic potential, application of enzymes as native proteins suffers several drawbacks. Many enzymes in aqueous solutions are relatively unstable and their recovery from such reaction mixtures may be difficult due to the high solubility of proteins in water. The catalytic activity, selectivity, specificity and enzyme stability are key factors affecting the efficiency of biocatalysts (1-6). Immobilization can enhance the key properties of the biocatalysts such as stability and convenience of recovery and reuse (3-45).
Lipases (EC 3.1.1.3, triacylglycerol esterases) which normally catalyze the hydrolysis of triacylglycerols to fatty acids, mono-, and diacylglycerols, and glycerol are the most frequently used biocatalysts. Biotransformations with lipases are extensively studied because in organic solvents with low-water content, synthetic reactions are favoured and the enzymes have their stability increased (2, 6). Since lipases are stable, easy to handle and possess rather broad substrate specificity, and a high enantio- and regioselec ...