Heterologous expression of lipases YLIP4, YLIP5, YLIP7, YLIP13, and YLIP15 fromYarrowia lipolyticaMSR80 inEscherichia coli: Substrate specificity, kinetic comparison, and enantioselectivity

Five lipase genes,ylip4,ylip5,ylip7,ylip13, andylip15, fromYarrowia lipolyticaMSR80 were cloned and expressed in the pEZZ18‐HB101 system. The lipases shared maximum sequence identity withCandida gallilipase, whereas they shared structural similarity with YLIP2 ofY. lipolyticaCLIB122. The enzymes, purified using IgG sepharose, had specific activities in the range of 7–25 U mg−1. Biochemical characteristics of all the lipases varied with respect to thermostability, substrate specificity, and enantioselectivity. All the enzymes were most active at neutral or slightly alkaline pH and were stable in the pH range 3.0–8.0, except YLIP4, which showed 50% stability at pH 10.0. Temperature optima of all the lipases varied from 30 to 50 ºC. YLIP15 and YLIP13 were most thermostable with at1/2of 138 and 112 Min, respectively, at 60 °C. The lipases exhibited varied substrate specificity onp‐nitrophenyl esters ranging from short‐chain specificity (YLIP15), mid‐chain specificity (YLIP4, YLIP5, YLIP7), and long‐chain specificity (YLIP13). Catalytic efficiency onp‐nitrophenylcaprate was highest for YLIP13 (67 × 103mM−1min−1) and lowest for YLIP15 (6.7 × 103mM−1min−1). YLIP13 was S‐enantioselective, and YLIP15 was R‐enantioselective with enantiomeric excess of 53 and 36%, respectively. Of all five lipases, YLIP13 and YLIP15 could be considered as industrially important enzymes as they were thermostable and enantioselective.