磺胺甲恶唑高效降解菌群的多样性分析和降解微生物的分离表征

为了解决养殖水体中抗菌药物磺胺甲恶唑残留污染的问题，以抗菌药物磺胺甲恶唑为唯一碳源，通过连续4次传代富集，获得了磺胺甲恶唑降解菌群。通过16S V3-V4区高通量测序分析了每个代次的群落组成和丰度变化，推测了与磺胺甲恶唑降解相关的菌株信息，进一步连续分离纯化到了磺胺甲恶唑降解菌株LLE3。经16S rDNA及生理生化鉴定，初步将LLE3鉴定为鞘氨醇杆菌属（Sphingobacterium）菌株。对该菌进行了降解条件优化，在最优降解条件下（30 ℃，pH 7，接种浓度为5×107 CFU·mL-1），该菌7 d内对50 mg·L-1的磺胺甲恶唑降解效率可达93.7%。运用高效液相色谱与质谱联用鉴定了菌株LLE3降解后的代谢产物为N-\4-(1，2-恶唑-3-基氨磺酰基)苯基\]乙酰胺。研究结果为磺胺甲恶唑污染的水体和土壤环境修复提供了优良的微生物资源。

Diversity Analysis of Sulfamethoxazole Degradation Community and Isolation and Characterization of Degrading Microorganism

In order to solve the pollution caused by sulfamethoxazole in aquatic water,the antibacterial agent sulfamethoxazole was used as the sole carbon source,and the microflora to degrade sulfamethoxazole was obtained by four continuous subculture enrichment.16S V3-V4 high-throughput sequencing was used to analyze the community composition and the abundance changes in each generation of bacteria,and the strain information related to sulfamethoxazole degradation was speculated.The strain LLE3 to degrade sulfamethoxazole was obtained by further isolation and purification.LLE3 was preliminarily identified as Sphingobacterium by 16S rDNA and physiological and biochemical identification.The degradation conditions of the bacteria were optimized.Under the optimal degradation conditions(30℃,pH 7,inoculation concentration of 5×10⁷ CFU·mL^-1),the bacteria can degrade 50 mg·L^-1 sulfamethoxazole with an efficiency of 93.7%within 7 days.The metabolite degraded by strain LLE3 was identified as N-4-(1,2-oxazol-3-yl sulfamoyl)phenyl]acetamide by high performance liquid chromatography and mass spectrometry.These results provide excellent microbial resources for the remediation of water and soil environment polluted by sulfamethoxazole.