河南农业大学学报2025，Vol.59Issue(4)：657-665,9.DOI:10.16445/j.cnki.1000-2340.20250114.001
高效降解土壤甲基二磺隆菌株的筛选、鉴定及特性
Screening,identification,and characterization of efficient degradation strains for mesosulfuron-methyl in soil
摘要
Abstract
[Objective]Screening and identification of strains capable of efficiently degrade mesosulfuron-methyl in soil,and investigating their degradation characteristics and processes,to pro-vide a feasible microbial remediation technology solution for addressing mesosulfuron-methyl soil resi-dues.[Method]Soil samples were collected from areas that had been continuously sprayed with mesosulfuron-methyl for five years,and the degradation rate of mesosulfuron-methyl was used as an indicator.Mesosulfuron-methyl was used as the sole carbon source in an enrichment and domestication process to screen for the effective degrading strain.Bacterial species were identified based on 16S rDNA sequencing,combined with morphological,physiological,and biochemical characteristic.The degradation conditions of the degrading strain(inoculum volume fraction,temperature,pH value)were investigated.High-performance liquid chromatography-mass spectrometry(HPLC-MS)was employed to detect and identify the degradation products of mesosulfuron-methyl by the strain,and the degradation pathway was subsequently inferred.The toxicity of the degradation products was analyzed using the ecological structure-activity relationship(ECOSAR)model.[Result]The strain D161 with high-efficiency degradation of mesosulfuron-methyl was screened and identified as Pseudomonas citro-nellolis.Under the optimized conditions with an inoculum volume fraction of 5%,37℃,and a pH value of 7.0,the strain D161 achieved a degradation rate of 48.44%for mesosulfuron-methyl with a mass concentration of 10 mg·L-1 within 7 days.Seven main degradation products of mesosulfuron-methyl by strain D161 were identified using HPLC-MS,which are methyl4-(methanesulfonamido-methyl)-2-aminosulfonamidobenzoate(M1),4,6-dimethoxypyrimidin-2-amine(M2),N3-(1-methyl-1-oxo-1-phenyl-λ6-sulfanylidene)-2-(methylthio)nicotinamide(M3),2,4-dihydroxy-5-methylpyrimi-dine(M4),2-amino-4-hydroxypyrimidine(M5),phthalic acid(M6),and benzoic acid(M7).Based on these findings,the proposed degradation pathway involves the cleavage of the C-N bond in the sulfo-nylurea bridge of mesosulfuron-methyl,producing M1 and M2,which are further degraded into smaller molecules fragments.Toxicity analysis using the ECOSAR model indicates that the toxicity of the degradation products of mesosulfuron-methyl by strain D161 is lower than that of mesosulfuron-methyl itself.[Conclusion]The degrading strain D161 exhibits excellent degradation capabilities for mesosulfuron-methyl,which is beneficial in reducing the soil residue of mesosulfuron-methyl and enriching the strain resources for the remediation of sulfonylurea herbicides contaminated soils.关键词
甲基二磺隆/香茅醇假单胞菌/降解途径/生态结构活动关系模型/毒性Key words
mesosulfuron-methyl/Pseudomonas citronellolis/degradation pathway/ecological struc-ture activity relationship model/toxicity分类
资源环境引用本文复制引用
张晓东,刘赵磊,贺文星,田甜甜,吴仁海,徐淑霞..高效降解土壤甲基二磺隆菌株的筛选、鉴定及特性[J].河南农业大学学报,2025,59(4):657-665,9.基金项目
河南省重点研发专项(221111112300) （221111112300）
河南省"三区"科技人才支持计划(30803566) （30803566）
