Construction of Carbendazim Degrading Bacteria and Evaluation of Its Residue Degradation Effect in Tobacco Leaves

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.