Optimization of Recombinant Novel Esterase Expression from Extremophiles

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 of isopropyl β-D-1 thiogalactopyranoside (IPTG) concentrations were applied. In addition, induction at 25 ºC for 16 hours, 30 ºC for 6 hours and 37 ºC for 3 hours were tested. According to the results, induction at 30 °C for 6 hours by 0.1 mM of 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.