一株脂肪酶产生菌及其脂肪酶催化性质的初步研究

A lipase-producing strain and its catalytic characteristics

从各种含油脂的土壤中筛选分离到一株高选择性拆分(R,S)-2-羟基-4-苯基丁酸乙酯[(R,S)-HPBE]的产脂肪酶菌株CF-12,经形态观察、生理生化试验和16S rDNA序列分析,鉴定该菌为沙雷氏菌属(Serratia sp.)。对菌株CF-12产脂肪酶的发酵条件进行了初步优化,确定最适产酶条件为:蔗糖5 g/L,酵母粉10 g/L,金属离子Mg2+0.75 mmol/L,发酵培养24 h,脂肪酶活性可达20.1 U/mL。该脂肪酶最适反应温度和pH值分别为40℃和7.0。利用冻干酶粉拆分(R,S)-HPBE 15 h,(R)-HPBE产率达39.6%,ee=90.8%。

A lipase-producing strain of CF-12,which could used as the selective kinetic resolution of（R,S）-2-hydroxy-4-Ethyl benzene [（R,S）-HPBE],was isolated from a variety of rich oil soil.It was identified as Serratia sp.by its morphological,physiological properties and 16S rDNA sequence analysis.The preferred carbon source,nitrogen source and metal ion were sucrose（5 g/L）,yeast powder（10 g/L）,and Mg2＋（0.75 mmol/L）,respectively.After 24 h cultivation,the lipase activity was 20.1 U/mL.The optimal reaction temperature and pH were 40 ℃ and 7.0,respectively.After 15 h resolution by crude enzyme powder,（R）-HPBE could be obtained with the yield of 39.6% and e.e.of 90.8%.