Remediation of thiamethoxam contaminated wetland soil by Phanerochaete chrysosporium and the response of microorganisms

Abstract

The extensively used neonicotinoid pesticides are reported seriously threatened ecological environment and even human health, which is one of the most urgent environmental problems. In this study, the bioremediation of thiamethoxam contaminated wetland soil by Phanerochaete chrysosporium and the analysis of microorganisms' response was conducted. Results showed that P. chrysosporium improved thiamethoxam degradation both in non-sterilized and sterilized soils. Obvious bioaugmentation of thiamethoxam degradation was especially found in non-sterilized soil at the earlier stage (< 10 d). The pH of the soils increased accompanied with the decreasing in organic matter after remediation. Increase in invertase activity and decrease in urease activity was observed, while the catalase activity changed little. Microbial community analysis illustrated that phyla Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were the dominate species for bacteria, and phyla Ascomycota, Basidiomycota were the dominate species for fungi. P. chrysosporium inoculation in different modes shifted the composition and relative abundance of microbial community differently, but increased in microbial diversity in soil was observed overall. The obtained results proved that white-rot fungus P. chrysosporium enhanced elimination was available for bioremediation of thiamethoxam contaminated soil.