Metabolic engineering ofLactococcus lactisinfluence of the overproduction of lipase enzyme

Abstract

The dairy industry uses lipase extensively for hydrolysis of milk fat. Lipase is used in the modification of the fatty acid chain length, to enhance the flavours of various chesses. Therefore finding the unlimited source of lipase is a concern of dairy industry. Due to the importance of lipase, this study was an attempt to express the lipase fromBurkholderia cepaciainLactococcus lactis.To achieve this, a gene associated with lipase transport was amplified and subcloned in inducible pNZ8148 vector, and subsequently transformed intoLc. lactisNZ9000. The enzyme assay as well as SDS-PAGE and western blotting were carried out to analysis the recombinant lipase expression. Nucleotide sequencing of the DNA insert from the clone revealed that the lipase activity corresponded to an open reading frame consisting of 1092 bp coding for a 37·5-kDa size protein. Blue colour colonies on nile blue sulphate agar and sharp band on 37·5-kD size on SDS-PAGE and western blotting results confirm the successful expression of lipase byLc. lactis. The protein assay also showed high expression, approximately 152·2 μg/ml.h, of lipase by recombinantLc. lactis.The results indicate thatLc. lactishas high potential to overproduce the recombinant lipase which can be used commercially for industrially purposes.