一株脂肪酶产生菌的筛选鉴定及其发酵条件优化

Isolation,identification of a lipase-producing bacterium and its optimized fermentation conditions

利用罗丹明平板法从油污污染土壤中分离得到一株脂肪酶产生菌CSL1,对其形态学、生理生化特征进行鉴定,并结合16SrDNA基因序列分子生物学鉴定及系统发育学分析,结果表明该菌株属于沙雷氏菌(Serratia.sp)。首先采用单因素试验研究发酵时间、温度、装液量、摇床转速、接种量对其产酶影响,在此基础上,采用正交实验确定菌株CSL1的最佳发酵条件为培养基装液量150mL,10%接种量,发酵温度30℃,发酵周期48h,在此条件下发酵液粗酶活为2.39U/mL。

A lipase-producing strain CSL1 was isolated from oil-polluted soil by Rhodamine B-contained medium,and identified by morphologic and physiolgic methods,and 16SrRNA gene phylogenetic analysis.The results showed that the strain is a member of the genus Serrtia.The effect of fermentation time,temperature,inoculum,rotating speed and liquid volume on the lipase activity of fermentation broth were investigated by single factor experiments.Optimized by orthogonal experiments,the results showed that the best lipase-producing conditions were:loading volume 150mL/250mL,inoculum amount 10%(v/v),fermentation temperature 30℃,and fermentation time 48h.Under the above conditions,lipase activity reached to 2.39U/mL,which was 1.3 times more than that of before optimization.