Causes of unreproducibility of C. rugosa lipase-catalyzed reactions in slightly hydrated organic media

Abstract

Lipase activity, measured as hydrolysis of tributyrin is a valid assay to quantify the lipase activity of a lyophilized crude lipase in hydrolysis reactions but it is not useful to predict the catalytic activity in lipase-catalyzed reactions in organic media. Three factors control the catalytic activity in these media: i) relative proportion of isoenzymes; ii) amount of water in the lyophilized crude enzyme and iii) amount of lipase protein in the commercial powder. Thus we propose two simple reaction tests: i) heptyl oleate synthesis (specific of lipases), ii) enantioselective esterification of (R) or (S) 2-(3-benzoyl)phenyl propionic acid. This methodology is applied to different crude lipases of Candida rugosa, obtained in different fermenter conditions and shows the origin of the unreproducibility of the synthetic data.