Bioremediation of Historically Chlorimuron-Ethyl-Contaminated Soil by Co-Culture Chlorimuron-Ethyl-Degrading Bacteria Combined with the Spent Mushroom Substrate.

In this study, a novel chlorimuron-ethyl-degrading -SMS-CB was successfully constructed for remediation of soil historically contaminated with chlorimuron-ethyl. The -SMS-CB was prepared using efficient chlorimuron-ethyl-degrading cocultured bacteria, sp. D310-1 and sp. D310-5, with spent mushroom substrate (SMS, a type of agricultural waste containing laccase) of as a carrier. The chlorimuron-ethyl degradation efficiency in historically chlorimuron-ethyl-contaminated soil reached 93.1% at the end of 80 days of treatment with the SMS-CB. Although the SMS-CB altered the microbial community structure at the beginning of the 80 days, the bacterial population slowly recovered after 180 days; thus, the SMS-CB does not have an excessive effect on the long-term microbial community structure of the soil. Pot experiments indicated that contaminated soil remediation with SMS-CB reduced the toxic effects of chlorimuron-ethyl on wheat. This paper is the first to attempt to use chlorimuron-ethyl-degrading bacterial strains adhering to SMS to remediate historically chlorimuron-ethyl-contaminated soil, and the microbial community structure and SMS-CB activity in chlorimuron-ethyl-contaminated soil were traced in situ to evaluate the long-term effects of this remediation.