Optimization of recombinant novel esterase expression from extremophiles

Abstract

Esterases, which are a sub-group of lipolytic enzymes, are important biocatalysts for many industrial applications. In this study, optimization for the recombinant expression of a novel esterase, which was previously obtained by metagenomic approach, was studied. To optimize the expression, 0.1, 0.5 and 1 mM isopropyl β-D-1 thiogalactopyranoside (IPTG) concentrations were tried. In addition, induction at 25ºC for 16 hours, 30ºC for 6 hours and 37ºC for 3 hours were tried. According to the results, induction at 30°C for 6 hours by 0.1 mM IPTG yielded high amount of protein with maximum catalytic activity. After the gene was successfully expressed, purification studies were conducted. The protein was purified using His-tag method. Native and SDS-PAGE analysis showed that protein which is present as a monomer was successfully purified.