降解胆固醇马红球菌F21-1的分离、鉴定及其特性研究

利用以胆固醇为唯一碳源的选择性培养基,从豚鹿粪便样品中分离出1株降解胆固醇良好的菌株。经生理生化鉴定和16S rDNA基因序列分析,该菌株为马红球菌(Rhodococcus equi)。该菌株降解胆固醇的最佳碳源为胆固醇,最佳氮源为蛋白胨、硝酸铵复合氮;最佳培养条件:温度为32℃,初始pH值为8.0,胆固醇质量浓度为1.50 g/L。在该培养条件下培养24 h,胆固醇的降解率可达到71.95%。

Isolation, identification of a new Rhodococcus equi F21-1with cholesterol degrading activity and study on its characteristic

A new strain which is able to degrade cholesterol was isolated from Hog Deer feces by using selective medium.The selective strain can use cholesterol as the sole carbon source.After the analysis of physiological-biochemistry characteristic and the 16S rDNA gene sequence,the strain was identified as Rhodococcus equi.The optimum carbon source is cholesterol,and the optimum nitrogen source is peptone.The optimum fermentation condition inclues temperature 32 ℃;initial pH 8.0;cholesterol concentration 1.50 g/L.If the strain incubates under that condition for 24 h,cholesterol-degrading rate will reach 71.95%.