Characterization of a Cold-Active Esterase from Lactobacillus plantarum Suitable for Food Fermentations

Lactobacillus plantarum is a lactic acid bacteria that can be found in numerous fermented foods. Esterases from L. plantarum exert a fundamental role in food aroma. In the present study, the gene lp_2631 encoding a putative esterase was cloned and expressed in Escherichia coli BL21 (DE3) and the overproduced Lp_2631 protein has been biochemically characterized. Lp_2631 exhibited optimal esterase activity at 20 degrees C and more than 90% of maximal activity at 5 degrees C, being the first cold-active esterase described in a lactic acid bacteria. Lp_2631 exhibited 40% of its maximal activity after 2 h of incubation at 65 degrees C. Lp_2631 also showed marked activity in the presence of compounds commonly found in food fermentations, such as NaCl, ethanol, or lactic acid. The results suggest that Lp_2631 might be a useful esterase to be used in food fermentations.