Abstract:A lipase from Bacillus thuringiensis CZW001 was purified to homogeneity using ammonium sulfate precipitation,dialysis,DEAE-cellulose-52 anion exchange chromatography and Sephadex G-75 gel filtration chromatography.This purification protocol resulted in a 75.5 fold purification of lipase with 37.6% final yield,and the relative molecular weight of the enzyme was determined to be approximately 40kD using SDS-PAGE.Preliminary stuies have shown that the enzymatic properties of bacteria lipase,the enzyme’s optimum temperature is 25 ℃ and the enzyme was thermal lability,only 30% of its activity was remained after 30 min incubation at 60 ℃.The enzyme showed high lipolytic from ph 7.0 to 9.0 and its optimal ph for activity was 8.0.Ca2+ions stimulated lipolytic activity,whereas Al3+、Zn2+and Fe2+ions caused inhibition.Lipase tolerance of organic solvents of alcohols with carbon chain decreases.Lipase on soybean oil showed a significant the hydrolysis of the lipase.
