一株有机溶剂稳定性蛋白酶产生菌的筛选与鉴定

为了筛选分泌有机溶剂稳定性蛋白酶耐有机溶剂极端微生物，利用添加苯10%(V/V)的MLB培养液从油污染水样中分离获得有机溶剂耐受菌株56株。通过产蛋白酶筛选培养基(SMA 培养基)平板初筛和摇瓶发酵复筛从中筛选获得蛋白酶高产菌株DS1。通过形态学、生理生化及16S rDNA序列(genbank EU578329)构建的系统进化树将菌株DS1鉴定为Bacillus aquaemaris。该菌株能耐受多种有机溶剂，并可以分泌有机溶剂稳定性蛋白酶。该蛋白酶在 25%极性常数(logPOW)大于等于1.8的有机溶剂中稳定性好，于30℃、140 r/min，培养14d仍有70%以上的活力。菌株DS1及其所分泌的蛋白酶均能较好的耐受有机溶剂，可以进行有机相催化，具有潜在的工业应用价值。

Screening and Identification of An Organic-solvent-stable Protease-producing Strain

In this study, 56 organic-solvent-tolerant strains were isolated from oil-pollution water by using MLB medium with 10% benzene (V/V) addition. Among them, the high-yield strain DS1 was finally obtained through the first screening with SMA plate and the second screening with shake flask fermentation. The strain DS1 was identified as Bacillus aquaemaris by its morphological, physiological, biochemical characteristics and 16S rDNA sequence homology. The verifying test showed that the strain DS1 can tolerant organic solvents at different levels, and the organic-solvent-tolerant protease excreted by strain DS1 also has a nice tolerance to organic solvents. This protease is stable in 25% organic solvents with logPow equal to or more than 1.8, and may keep above 70% activity after 14-d cultivation at 30 ℃ and 140 r/min. It was expected that both of the strain DS1 and its protease can be used as catalysts for reactions in organic phase, and have huge potential in industrial application.