毒死蜱降解菌株的分离、鉴定及降解条件优化

Isolation and identification of chlorpyrifos degradation strains and optimization of degradation conditions

目的:分离筛选出高效降解毒死蜱菌株,明确其生物学分类地位,并优化其降解条件.方法:采取平板划线和摇瓶复筛法从农药厂土壤样品中分离得到高效降解毒死蜱菌株,并通过16S rRNA序列测定和同源性分析对其进行鉴定;运用HPLC法检测降解菌株对毒死蜱的降解效果,研究其在不同培养基、接种量、温度及pH条件下的降解能力.结果:从农药厂土壤样品中筛选得到一株能够以毒死蜱为唯一碳源生长的高效降解菌株OP7,经16S rRNA基因序列聚类分析,将其初步鉴定为粪产碱杆菌(Alcaligenes faecalis).进一步的降解条件优化结果显示,菌株OP7降解毒死蜱的最佳培养基是10%LB、最适接种量为3%(v/v)、最适温度为35℃、最适初始pH为9.0.结论:本研究结果表明菌株OP7有望成为新的菌种资源并应用于环境中毒死蜱污染物的生物修复.

Objective:To isolate and screen strains with high efficiency for degrading chlorpyrifos,clarify their biological classification status,and optimize their degradation conditions.Method:Plate streak and shake flask re-screening were used to isolate the high-efficiency chlorpyrifos-degrading strains from soil samples of a pesticide factory,and these isolated strains were identified by 16S rRNA sequence determination and homology analysis;HPLC was used to detect the degradation effects of chlorpyrifos by degrading strains on different medium,inoculum,temperature,and pH conditions.Result:A high-efficiency degrading strain OP7 was screened from soil samples of a pesticide factory and could grow with chlorpyrifos as the sole carbon source.Based on its 16S rRNA gene sequence cluster analysis,strain OP7 was preliminarily identified as Alcaligenes faecalis.The optimization of degradation conditions for chlorpyrifos degradation by strain OP7 were 10%LB,35℃,pH 9.0,and an inoculum size of 3%(v/v).Conclusion:Strain OP7 is expected to become a new bacterial resource and be applied to the bioremediation of chlorpyrifos pollutants in the environment.