一株氯嘧磺隆降解菌分离鉴定及降解条件优化

Isolation and identification of a chlorimuron-ethyl-degrading bacterium and optimization of its degradation conditions

摘要:

为解决氯嘧磺隆残留对土壤、水体污染及后茬敏感作物药害问题，为污染土壤微生物修复提供降解菌种资源，文中采用富集培养、逐级驯化等方法，从氯嘧磺隆污染土壤中分离到1株高效氯嘧磺隆降解菌T9DB-01，经形态特征、生理生化及16S rDNA序列分析，鉴定为假单胞菌Pseudomonas sp.。采用单因素实验探究温度、pH值、底物浓度、装液量和接种量对菌株T9DB-01降解氯嘧磺隆的影响，采用正交试验及验证，优化菌株T9DB-01对氯嘧磺隆降解条件。结果表明，在30 ℃，pH 8.0，底物浓度200 mg/L，装液量100 mL/250 mL，接种量4%的条件下，5 d后降解率达到93.7%。该降解菌株对氯嘧磺隆污染土壤原位生物修复具有一定的应用潜力。

Abstract:

In order to solve the problem of soil, water pollution and sensitive crop drug damage caused by chlorosulfuron residue, and to provide degradation strain resources for microbial remediation of contaminated soil, a chlorimuron-ethyl-degrading strain T9DB-01 was isolated from chlorosulfuron contaminated soil by the method of enrichment culture and step by step domestication. Strain T9DB-01 was identified as Pseudomonas sp. by morphological characteristics, physiological and biochemical analysis and 16S rDNA gene sequence analysis. The effects of temperature, pH value, substrate concentration, medium volume, and inoculation volume on the degradation of chlorsulfuron-methyl by strain T9DB-01 were investigated by single factor experiment. The degradation conditions of chlorosulfuron by strain T9DB-01 were optimized by orthogonal test and verification. Results show that 30 °C, pH 8.0, inoculum 4%, liquid volume 100 mL/250 mL, substrate concentration of 200 mg/L, cultured for 5 d, the strain degraded 93.7% chlorsulfuron-methyl. The degrading strain has certain application potential for bioremediation of chlorsulfuron-contaminated soil.