关键词: 脂肪酶, 洋葱伯克霍尔德氏菌, 发酵条件优化, 酶学性质

Abstract: It is aimed to optimize the fermentation conditions of lipase-producing Burkholder cepacia Lu10-1 and analyze its enzymatic properties. The single factor and orthogonal experiments were adopted to study the major factors that affected the lipase yield, such as carbon, nitrogen, inducer, initial pH, temperature, etc. The impact of temperature, pH, metal ion, and organic solvents on lipase catalytic reaction was also primarily investigated. The optimal medium and culture conditions were as follows： soluble starch 1.5%, peptone 1.5%, olive oil 3 g/L, K₂HPO₄ 2 g/L, temperature 32℃, initial pH 9.0, and fermentation time 48 h, the enzyme activity reached 12.4 U/mL, increased 2.7-fold compared to the initial activity. The optimal temperature and pH were 60℃ and 9.0 respectively. The lipase was stable under 60℃ for 100 h remaining over 80% of the activity and it was also stable at pH 5.0-10.0. Moreover, the lipase had solid tolerance to organic solvent such as methanol and ethanol.

Key words: lipase, Burkhoideria cepacia, fermentation, enzymatic characterization