SUMMARY

The sol-gel entrapment is a relatively new technique of immobilization, a very powerful tool to improve almost all enzyme properties. Sol-gel entrapment of a microbial lipase (Amano AK, from Pseudomonas fluorescens) using as precursors tetramethoxysilane and alkyl- or aryl-trimethoxysilane has been investigated. The obtained preparates were tested for the kinetic resolution of aliphatic secondary alcohols: 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol and 2-octanol by acylation with vinyl acetate. The presence of octyl nonhydrolizable group in the sol-gel matrix resulted in the highest conversion and immobilization efficiency values, as the best enantioselectivity has been shown by the preparates containing phenyl groups. The present method could be effective for large scale applications to obtain optically active alcohols and esters