Abstract
Esterase is an industrial enzyme that is widely used in food, medicine, fine chemicals. The total genomic DNA was extracted from traditional fermented food in China to construct a metagenomic library that included a novel esterase gene (est_115). Sequence homology analysis showed that the highest homology with the carboxylester hydrolase from Pseudomonas lutea was 38%, indicating that esterase belongs to a new class of esterases. Then, an est_115 gene recombinant expression vector was constructed and expressed. The Est_115 had higher catalytic activity to p-nitrophenol ester, with a short acyl-carbon chain. The enzyme can maintain high catalytic activity and salt tolerance in 10%–18% NaCl, suggesting that this novel esterase can be used in processing food using high osmotic pressure.