Abstract: In order to maximize lipase production, culture conditions for Bacillus cereus SWWL6 having the ability to produce organic solvent tolerant lipase were optimized by L9(34) orthogonal array design. The optimal fermentation conditions were 55 mL of medium at pH 6.5 in 250 mL Erlenmeyer flask with 4% inoculum under orbital shaking of 150 r/min for 36 h at 35 ℃. The optimal pH for SWWL6 lipase ranged from 7.0 to 8.0. The enzyme was stable under alkaline conditions. The optimal temperature for SWWL6 lipase was 40 ℃, and its activity sharply declined at higher temperatures. The lipase activity was activated in the presence of K+, Na+, Mg2+ and Ba2+, and inhibited in the presence of Al3+, Cu2+, Zn2+, Ca2+, EDTA and SDS. Meanwhile, SDS was the strongest inhibitor.

Key words: lipase, Bacillus cereus, organic solvent tolerant