Extracellular expression and characterization of thermostable lipases, LIP8, LIP14 and LIP18, from Yarrowia lipolytica

Two new lipases, LIP14 and LIP18, along with LIP8 from Yarrowia lipolytica MSR80 were functionally expressed as extracellular proteins with an IgG tag using Escherichia coli HB101 pEZZ18 host vector system. Each enzyme had an optimal activity at pH 7 and 40 A degrees C and was activated by 6 mM Ca2+ and 90 % (v/v) non-polar solvents but inhibited by 10 mM of each 1,10-phenanthraline, DTNB, PMSF and N-bromosuccinamide. All the enzymes were thermostable with t(1/2) of 52 min, 49 min and 68 min for LIP8, LIP14 and LIP18 at 80 A degrees C, respectively. LIP18 was most thermostable among all with a high arginine: lysine ratio and proline content. All the three lipases showed a preference for oleic acid rich triacylglycerols and oils.