耐受有机溶剂洋葱伯克霍尔德菌ZYB002全细胞脂肪酶酶学性质

Properties of Whole-cell Lipase from Burkholderia sp.ZYB002 with Organic Solvent Tolerance

一株对多种有机溶剂具有良好耐受能力的产脂肪酶菌株ZYB002经分子鉴定为洋葱伯克霍尔德菌。其产生的细胞结合脂肪酶最适温度为65°C,最适pH为8.0,在低于70°C和pH3-8.5的范围内,全细胞脂肪酶保持稳定。Ca2+、K+、Na+和NO3-等离子对脂肪酶活性有激活作用,而Zn2+有抑制效应。全细胞脂肪酶对正丁醇有较强的耐受能力,但曲拉通X-100对脂肪酶活性有强烈的抑制效应。洋葱伯克霍尔德菌ZYB002全细胞脂肪酶良好的碱稳定性、热稳定性和有机溶剂耐受性,表明该全细胞脂肪酶具有重要的工业应用潜力。

The lipase-producing strain ZYB002 with broad-spectrum organic solvent-tolerance was identi- fied as Burkholderia cepacia complex by the recA sequence. The optimal pH and temperature for lipolytic activity of the cell-bound lipase from Burkholderia sp. ZYBO02 was 8.0 and 65℃, respectively. It was stable at temperature up to 70℃ and retained 79.2% of its original activity for 1 h. The lipase was highly stable in the pH range from 3.0 to 8.5 for 6 h. Ca^2＋, K^＋, Na^＋, NO3^-, etc. ions stimulated its lipolytic activity, whereas Zn^2＋ ions caused inhibition. The cell-bound lipase was also relatively stable in n-butanol at a final concentration of 50% （V/V） for 24 h. However, the lipase was strongly inhibited in triton X-100 at a final concentra-tion of 10% （V/V）. The cell-bound lipase with thermal resistance, alkaline resistance and organic solvent resistance showed its＇ great potential in various industrial application fields.