草甘膦降解菌的筛选及鉴定

目的 从经常施用有机磷农药的土壤中筛选出对草甘膦具有较高降解能力的菌株, 并对该菌株进行菌种鉴定, 以期开发草甘膦农药残留的降解菌并提高微生物的利用率。方法 以降解率为指标进行初筛, 经梯度驯化后计算降解速率和半衰期, 选取降解能力最佳的菌株T6, 并对菌种进行形态学、生理生化特性、糖发酵等试验以及分子生物学鉴定。结果 菌株T6经鉴定为植物乳杆菌, 在以草甘膦为唯一碳源的培养基中, 24 h降解率达27.51%, 降解速率常数为0.0192 h-1, 半衰期为36.10 h, 降解作用良好。结论 筛选出一株分解草甘膦农残效果较好的菌株, 经鉴定为植物乳杆菌, 对草甘膦的降解效果较好。本研究结果对开发利用微生物降解草甘膦等农残的研究, 具有一定的理论借鉴意义。

Screening and identification of glyphosate degrading bacteria

Objective Screen out strains with high degrading ability to glyphosate from the soil where organophosphorus pesticides are frequently applied, and identify the strains, in order to develop glyphosate pesticide residue degrading bacteria and improve the utilization rate of microorganisms. Methods Preliminary screening is performed based on the degradation rate index, and the degradation rate and half-life are calculated after gradient acclimation. The strain T6 with the best degradation ability is selected, and the strains are subjected to morphological, physiological and biochemical characteristics, sugar fermentation and other tests as well as molecular biology identification. Results Strain T6 was identified as Lactobacillus plantarum. In the medium with glyphosate as the sole carbon source, the degradation rate reached 27.51%, the degradation rate constant was 0.0192 h-1, the half-life was 36.10 h, and the degradation effect was good. Conclusion A strain with good effect on decomposing pesticide residues of glyphosate was screened out, and it was identified as Lactobacillus plantarum, which has good degradation effect on glyphosate. The results of this study have certain theoretical reference significance for the development and utilization of microbial degradation of glyphosate and other pesticide residues.