PURIFICATION AND CHARACTERIZATION OF A LIPASE FROM LACTOBACILLUS PLANTARUM 2739

A 65 kDa intracellular lipase from Lactobacillus plantarum 2739 was purified to homogeneity (482-fold, specific activity of 251 μmol/mg per min) and characterized. The purification procedure included chromatography with Q-Sepharose, Sephacryl 200, Phenyl-Superose and Mono Q. The 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 stable at 65C (D_65C= 18.6 min) and was irreversibly inactivated at 75C for 2 min. On triglycerides, the highest activity was determined on tributyrin but trilaurin and tripalmitin were hydrolyzed also. The Km on tributyrin was 2.31 mM. β-Naphthyl esters of fatty acids from C2 to C12 were hydrolyzed with a preference for β-naphthyl butyrate. After lipolysis, the fatty acid profiles in β-monoacylglycerols of milk fat showed similarities among porcine pancreatic lipase, rennet paste and lipase from Lb. plantarum 2739, but the bacterial enzyme caused a greater hydrolysis of C10 and C12 fatty acids esterified at the Sn-2 position of glycerol. The lipase was strongly inhibited by 1 mM Nethylmaleimide and iodoacetic acid, by 10 mM Hg²⁺ and Ag⁺, and was moderately stimulated by Ca²⁺ and Mg²⁺.