Catalytic profiles of lipolytic biocatalysts produced by filamentous fungi

Abstract

The aim of this work is to propose and evaluate a catalytic profile of biocatalysts with lipase activity based on four characteristic reactions of lipases. For that, the catalytic profiles of three lipolytic biocatalysts from strains of the genus Rhizopus produced by solid-state fermentation (SSF) were determined based on acyl-, regio-, enantio- and chemoselectivity. Four commercial lipases were also evaluated according to their catalytic selectivity. p-nitrophenol esters from C-4 to C-16 were used to evaluate the acyl selectivities of the biocatalysts. The three biocatalysts produced by SSF presented the highest hydrolytic activity on triglycerides of medium chain length (C-8). The use of high performance thin layer chromatography (HPTLC) allowed us to demonstrate the biocatalysts produced by SSF presented sn-1,3-regioselectivity. Based on the Quick E method, the biocatalysts preferentially acted on the S-enantioisomer of glycidyl butyrate esters. Although their E values were insufficiently high (< 5), they demonstrated 1,3-sn selectivity hydrolytic activity, and the ability to synthesise ester and amide bonds (benzyl oleate and N-benzyloleamide, respectively), validating them as promising biocatalysts for these types of applications.