PURIFICATION AND CHARACTERIZATION OF A LIPASE FROM LACTOBACILLUS-PLANTARUM-2739

A 65 kDa intracellular lipase from Lactobacillus plantarum 2739 was pu rified to homogeneity (482-fold, specific activity of 251 mu mol/mg pe r min) and characterized. The purification procedure included chromato graphy with Q-Sepharose, Sephacryl 200, Phenyl-Superose and Mono Q. Th e purified lipase was optimally active at pH 7.5 and 35C; it retained about 40% of the maximum activity at pH 5.0 and 15C. The enzyme was st able at 65C (D-65C = 18.6 min) and was Irreversibly inactivated at 75C for 2 min. On triglycerides, the highest activity was determined on t ributyrin but trilaurin and tripalmitin were hydrolyzed also. The K-m on tributyrin was 2.31 mM. beta-Naphthyl esters of fatty acids from C2 to C12 were hydrolyzed with a preference for beta-naphthyl butyrate. After lipolysis, the fatty acid profiles in beta-monoacylglycerols of milk fat showed similarities among porcine pancreatic lipase, rennet p aste and lipase from Lb. plantarum 2739, but the bacterial enzyme caus ed a greater hydrolysis of C10 and C12 fatty acids esterified at the S n-2 position of glycerol. The lipase was strongly inhibited by 1 mM N- ethylmaleimide and iodoacetic acid, by 10 mM Hg2+ and Ag+, and was mod erately stimulated by Ca2+ and Mg2+.