17β-雌二醇降解菌红球菌(Rhodococcus sp.)DS201的分离鉴定及其特性研究

Isolation,identification of 17β-estradiol-degrading Rhodococcus sp. strain DS201 and its degradation characteristics

从北京一药厂曝气池的活性污泥中驯化、分离得到一株能以17β-雌二醇为唯一碳源生长的高效降解菌DS201.经过对其进行形态学、生理生化和16SrDNA序列分析,初步鉴定为红球菌Rhodococcus sp.分析了温度、pH值、接种量、底物浓度等因素对DS201生长的影响.结果表明:DS201生长的最适温度为30℃,最适pH=7,最佳接种量为2%,最适底物浓度为5mg/L.通过正交实验分析,DS201降解17β-雌二醇的最优条件是:温度30℃,pH=7,接种量为1%;培养3d能使1mg/L 17β-雌二醇完全降解.通过质谱分析,17β-雌二醇的初级降解产物是雌酮.

A novel bacterium capable of degrading 17 β-estradiol（E2） was isolated from the activated sludge collected from wastewater treatment plant of pharmacy factory mainly producing contraceptive medicine in Beijing. According to its morphology, physiochemical characteristics and 16S rDNA sequence analysis, this strain was identified as Rhodococcus sp. By tests in shaking flasks, the effects of the conditions of growth was studied, and it was determined that the optimum conditions of growth for the strain was 30℃ ,pH= 7 and inoculum amount 2% and E2 initial concentration of 5 mg/L. The degrading conditions for strain DS201 was further optimized by tests in orthogonal tests. The results showed that the conditions for the degradation of E2 by strain DS201 were 30℃, initial pH= 7, and inoculum amount 1%,this strain could degrade E2 completely within 3 d with intial concentration of 1 mg/L. Mass spectrum analysis demonstrated estrone that the main catabolic intermediates during E2 degradation.