Cloning, characterization and expression of a novel lipase gene from marine psychrotrophic Yarrowia lipolytica

A marine Yarrowia lipolytica yeast, named Bohaisea-9145, was found to secrete a large amount of lipase into the medium. A gene coding for lipase was cloned from the genome of this strain and expressed successfully in Escherichia coli BL21 (DE3). A maximum activity of 17.6 U/mg was obtained from cellular extract of E. coli harboring the lipase gene. The recombinant lipase exhibits one band with a molecular mass of about 44 kDa on SDS-PAGE. The optimal temperature and pH of the purified lipase were 35°C and 8.5, respectively. The Km and Vmax values of the lipase for p-nitrophenyl laurate were 0.582 μM and 0.124 mmol min−1 mg−1 under 35°C, respectively. Additionally, the purified lipase showed a high activity and stability over a wide range of temperatures, especially in the low and moderate temperatures, suggesting its potential for industrial applications.