Cloning, expression and characterization of a new lipase from Yarrowia lipolytica

Bioinformatic analysis of the Yarrowia lipolytica CLIB122 genome has revealed 18 putative lipase genes all of which were expressed in Escherichia coli and screened for hydrolyzing activities against p-nitrophenyl-palmitate. One positive transformant containing an ORF of 1,098 bp encoding a protein of 365 amino acids was obtained. To characterize its enzymatic properties, the lipase gene was functionally expressed in Pichia pastoris. The resulting lipase exhibited the highest activity towards p-NP-decanoate at pH 7 and 35°C. In addition, the new lipase had a lower optimal temperature and pH compared to other Y. lipolytica lipases. It was noticeably enhanced by Ca2+, but was inhibited by PMSF, Hg2+ and Ni2+. The new lipase displayed the 1,3-specificity for triolein.