Covalent immobilization of lipases on activated hollow silica microspheres

Abstract

This study explores the covalent immobilization of three lipases (Lipase AK, from Pseudomonas fluorescens; Lipase PS, from Burkholderia cepacia; and CrL, from Candida rugosa) on four supports prepared by functionalization of mesoporous hollow silica microspheres (M540) with various bisepoxides as activating agents for production of novel lipase biocatalysts for enantiomer selective biotransformations of secondary alcohols. The influence of length, rigidity and hydrophobicity of the bisepoxide activating agents was investigated on the efficiency of immobilization and catalytic properties of the resulted twelve lipase biocatalysts. The hollow silica particles modified with the most beneficial bisepoxide activating agents resulted in novel biocatalysts capable for kinetic resolution of racemic 1-phenylethanol rac-1a and racemic octan-2-ol rac-1b with high activity and enantioselectivity.

Application of lipase immobilized on a hydrophobic support for the synthesis of aromatic esters

“…SEM was also used by Szokol et al. [56], to visualize the lipase Amano in silicas, demonstrating that the particles of its biocatalyst showed mono dispersion and effective immobilization.…”

“…Francolini et al [55] evaluated the immobilization performance of CRL on magnetic nanocomposite supports and figured out enzyme aggregates on the surface of the tested support revealed by SEM images. SEM was also used by Szokol et al [56], to visualize the lipase Amano in silicas, demonstrating that the particles of its biocatalyst showed mono dispersion and effective immobilization.…”

The rise of continuous flow biocatalysis – fundamentals, very recent developments and future perspectives

“…Several bisepoxides with different lengths, stiffnesses and hydrophobicities were selected and evaluated for the surface modification of hollow silica microspheres. 149,152 The epoxy functions of the activator-agent bind covalently to the enzymes instead of a simple adsorption on the silica surface. The introduced bisepoxide moieties can covalently bind amine-, thiol-and carboxylate-functional groups under mild conditions.…”

“…Moreover, the immobilized enzymes preserve their activity and selectivity in contrast to other covalent immobilization strategies because the enzyme's catalytically active site is not sterically hindered, especially if a longer and more flexible bifunctional linker is used. 149,152 Thanks to their properties and numerous typologies of these activating agents, bisepoxides with different lengths and characteristics of the linker chain can be designed. This represents a costefficient and easy to perform technique for fine-tuned surface carriers.…”