Isolation and screening of methyl disulfuron degrading microorganisms

Abstract

The widespread use of herbicides has caused significant pollution to the soil environment, which has seriously endan gered people’s life and development. Therefore, there is an urgent need for an effective method to control environmental soil pollution, and the degradation of residual pesticides by microorganisms is an effective bioremediation method developed in recent years. Taking the soil treated with methyl disulfuron as the research subjects, the microbial strains with high degrada tion effect on methyl disulfuron were isolated by plate gradient dilution method, the isolated strains were enriched and cul tured, medicated and cultured, and soil colonization test, so as to determine the effect of methyl disulfuron on the strains. The results showed that a bacterium J20191108-1 and a fungus Tr20191108-E were isolated from soil, and no actinomy cetes were isolated. The bacterial colony is milky white, the surface is wet and smooth, and the fungus is preliminarily iden tified as Trichoderma. The bioaccumulation test of bacteria J20191108-1 showed that there was no significant difference in the external morphology and number of bacterial colonies growing on the two media with and without chemicals, in the soil colonization test, the bacteria grew better in the medium with herbicides. Trichoderma Tr20191108-Ecultured on plates with different drug contents had little effect on colony growth. Fungus grew all over the plate after 2 days of culture. The variance analysis of the spore yield of the fungus by SPSS showed that the p value was 0.163 > 0.05, indicating that there was no significant difference between the concentration of methyl disulfuron and the spore yield of the fungus. It can be seen that the concentration of methyl disulfuron has little effect on the external morphology of bacteria, but the concentration of pesti cide has a certain effect on the growth rate of fungi.