陈芊如 余佳敏 胡希好 苟春苗 丁蓬勃 荆常亮 杨英杰 李斌 李义强

摘  要：为控制烟叶中多菌灵农药残留，利用降解酶基因质粒载体克隆技术，合成构建了对多菌灵具有较好降解效果的菌株MBC2019，并进一步筛选优化了其发酵条件和最佳浓度，研究了降解菌在烟叶种植、烘烤和打叶复烤阶段对烟叶多菌灵农药残留降解的效果。结果表明，降解菌的最佳培养温度为28 ℃，最适培养pH为7.0，最优接种浓度为3.00%。种植阶段，喷施多菌灵和降解菌后3～7 d，未喷施降解菌烟叶中农药残留降解速度快于降解菌处理，14 d后降解菌的促进效果开始显现，未使用降解菌的降解率为96.55%，使用降解菌的降解率提高到99.58%;在烘烤和打叶复烤阶段，未使用降解菌的烟叶中多菌灵降解较慢，120 h降解率为8.07%和8.05%，喷施降解菌后，同期降解率分别达到77.97%和45.08%。因此该降解菌可用于烟叶种植，特别是烘烤和打叶复烤等阶段的多菌灵农药残留降解，具有良好的应用前景。

关键词：多菌灵;农药残留;烟叶种植;烘烤;打叶复烤;微生物降解

Abstract： In order to control carbendazim pesticide residues in tobacco leaves， the strain MBC2019 with good degradation effect on carbendazim was synthesized and constructed by using the cloning technology of degradation enzyme gene plasmid vector. The fermentation conditions and optimal concentration were screened and optimized， and the degradation effects of carbendazim pesticide residues in tobacco leaves during planting and curing and redrying were evaluated. The results were as follows： the degradation bacteria was successfully synthesized and constructed， the optimal culture temperature was 28 ℃ and pH was 7.0， and the best inoculation concentration was 3.00%. In the field conditions， the pesticide residues in tobacco leaves were degraded rapidly due to photolysis， growth dilution， microbial degradation and other factors in 3-7 days. The degradation-promoting effect of degrading bacteria began to appear 14 days later. At this point， the degradation rates were 96.55% without application and 99.58% with application in tobacco leaves. During curing and redrying stages， the carbendazim degradation rates were 8.07% and 8.05% without application， differing from the degradation rates of 77.97% and 45.08% with application at 120 h. The degradation bacteria could be used to degrade carbendazim residues in tobacco leaves at different stages， especially at the curing and redrying stages， which showed a good application prospect.

Keywords： carbendazim; pesticide residues; tobacco planting; curing; redrying; microbial degradation

多菌靈作为一种内吸性杀菌剂，具有高效、低毒、广谱的特点，对农作物的白粉病、根黑腐病、赤星病等[1]有较好的防治效果，在农作物生产中使用普遍，烟叶样品中多菌灵农药残留检出率高，对烟叶的品质与安全有较大影响[2]。目前烟叶中多菌灵农药残留量限量值为2 mg/kg，被作为一类风险农药管理[3]。为进一步明确多菌灵农药残留的形成机理与降解对策，国内外专家针对烟叶中多菌灵残留展开了一系列研究[4]，明确了其在烟叶冻干、杀青过程中的降解规律和有效降解方式。……