产海洋细菌MP-2酯酶菌株的鉴定及酯酶理化性质的研究

Identification of MP-2 esterase-producing marine Bacillus and study on properties of the esterase

从渤海海泥样品中分离获得1株新型酯酶菌株,经鉴定为地衣芽孢杆菌Bacillus licheniformis。所得的MP-2酯酶的最适作用温度范围50～70℃,在60℃表现出了最高活性,属于耐热酶;最适作用pH为10,属于碱性酶,其pH值作用范围比较窄;具有良好的热稳定性;金属离子Co2+,Li+对酶具有激活作用,Ca2+对酯酶的活力没有显著影响,化学试剂SDS、EDTA及Tween-20对酯酶的抑制效果显著,对常见有机溶剂具有良好的耐受力;该酯酶对碳链长短不同的底物表现出不同的酶活。

A novel marine esterase-producing bacteria isolated from the Bohai Sea sediment was identified as Bacillus licheniformis. The MP-2 esterase was primarily purified and characterized. The optimal range of temperature of the esterase was 50-70 ℃, and the maximum activity was achieved at 60 ℃ and pH10.0. The esterase was alkaline and its optimum range of pH was narrow. The thermal stability of the esterase was good. Co^2＋,Li＋ ions were found to activate the esterase, but Ca^2＋ had no significant effects on the activity of the esterase. While SDS, EDTA and Tween-20 had significantly suppressive effects on the esterase. It showed strong resistance to ordinary organic solvents. The enzyme exhibited different esterase activities towards substrates with different length of carbon chains.