中文摘要：

以体积分数10%的甲苯等有机溶剂为筛选压力,从油污和污水等样品中筛选到一株产耐有机溶剂脂肪酶的有机溶剂耐受菌LX1,经16 S rDNA序列分析,该菌株鉴定为Pseudomonas aeruginosa。研究发现菌株LX1所产脂肪酶最适反应pH和温度分别为7.0和40℃,在较宽的pH范围内（6.5～10.5）具有较高的稳定性;金属离子鏊合剂EDTA和Ba^2＋、Ca^2＋对LX1脂肪酶活力均有明显的激活作用,推测该脂肪酶为金属激活酶。LX1脂肪酶在体积分数25%的疏水性和亲水性有机溶剂中均具有较好的耐受性,在十六烷、十四烷、十二烷、正庚醇、正辛醇和正己醇体系中半衰期显著延长到10 d以上,在DMF和DMSO体系中的半衰期为5 d以上,均高于在无溶剂体系中的半衰期。展现了LX1脂肪酶在有机相生物催化中的良好应用前景。

英文摘要：

This manuscript describes the isolation of LX1 strain producing solvent-tolerant lipase from areas contaminated by crude oil and chemicals under the screening pressure of 10% （V/V） toluene. The isolate LX1 was identified as Pseudornonas aeruginosa by the analysis of 16S rDNA sequence. The optimal pH and temperature for lipase activity was 7.0 and 40 ℃, indicating the characteristic of neutral and medium temperature lipase. High stability of LX1 lipase was observed under a wide range of pH （6.5-10. 5）, and it was stable below 40℃. The chelating agent EDTA and metal ions such as Ba^2＋ , Ca^2＋- had significantly activated the activity of LX1 lipase. This suggested that it could be a metal activated enzyme. LX1 lipase showed good tolerance in many kinds of 25 % （V/V）hydrophilic and hydrophobic solvents. In the presence of n-Hexadecane, n-Tetradecane, n Dodecane, n-Octanol, n-Heptitol and n-Hexanol, the half-life of LX1 lipase was markedly prolonged to 10 d; Additionally, in the presence of propylene glycol, DMF and DMSO, the half-life of LX1 lipase was prolonged to 5 d, which were higher than the half-life without organic solvents. These results indicated that LX1 lipase has potential application in organic solvents.