苯扎贝特降解菌的筛选及降解特性

Isolation of a bacterial strain capable of bezafibrate-degrading and biodegradation characteristics

【目的】药品苯扎贝特在水环境中频繁检测出,对环境的潜在危害不容忽视。我们筛选分离降解苯扎贝特的细菌,并研究其降解特性。【方法】根据分离菌株的细胞形态结构、生理生化特征及其16S rRNA基因序列分析鉴定降解菌,高效液相色谱法测定苯扎贝特,以判定该菌株的降解能力。【结果】分离菌株B-31属恶臭假单胞菌(Pseudomonas putida),降解机制是共代谢。降解最佳条件为30℃、pH7。此条件下,以1%甲醇为初级基质,30mg/L苯扎贝特的5日降解率为48%。当分别以5g/L葡萄糖、蛋白胨、酵母粉为初级基质时,可使降解率提高到61%,、72.6%、76.67%。【结论】这是国内首次报道恶臭假单胞菌可以通过共代谢降解苯扎贝特,该研究为利用细菌发酵消除水环境中苯扎贝特污染提供基础。

[ Objective] Bezafibrate is one of the most frequently detected pharmaceuticals at relatively high concentration in surface water and even in drinking water. Biodegradation is an important way to solve the problem. This study aimed to isolate, identify and characterize a bezafibrate-degrading bacterium. [ Methods ] Strain B31 capable of degrading bezafibrate by cometabolism was isolated from activated sludge of sewage treatment plant in Shanghai, China, and identified based on its morphology, physiology and phylogenetic analysis of 16S rRNA sequence. To evaluate the ability of degradation, the concentration of bezafibrate was detected by high performance liquid chromatography. [ Results ] Strain B31 was identified to be closely related to Pseudomonas putida. The optimum condition of degrading bezafibrate was at 30℃ , pH 7. After 5 days, Strain B31 could degrade 30 mg/L bezafibrate by 48% in liquid mineral salt medium with 1% methanol as primary substrate. And the rate of degradation could enhance to 61% , 72.6% , 76.67% , when 5g/L glucose, peptone and yeast extract as primary substrate, respectively. [ Conclusion ] The strain has the potential for bezafibrate hiodegradation.