Purification and characterization of lipase from psychrophilic Acinetobacter calcoaceticus LP009

A lipase-producing bacterium, Acinetobacter calcoacetius LP009, was isolate d from raw milk. The optimum conditions for growth and lipase production by A. calcoaceticus LP009 were 15 degrees C with shaking at 200 rpm in LB sup plemented with 1.0% (V/V) Tween 80. The crude lipase was purified to homoge neous state by ultrafiltration and gel filtration chromatography on Sephade x G-100. Its molecular weight determined by SDS-PAGE was 23 kDa and it exhi bited maximum activity at pH 7.0 and 50 degrees C. It was stable over the p H range of 4.0 to 8.0 and at temperatures lower than 45 degrees C. It was a metalloenzyme that is positionally non-specific and had the ability to imp rove fat hydrolysis in soybean meal and in premixed animals feed.