Catabolic profiles dynamics during the bioremediation process of chlorimuron-ethyl contaminated soil by Methanolivorans CHL1

摘要

Excessive application of the long-term herbicide chlorimuron-ethyl has resulted in series of environmental problems. Bioaugmentation usually a useful method in contaminated-environment remediation. In this study, the strain Methanolivorans CHL1(T) with highly chlorimuron-ethyl degrading efficiency was employed to assess its remediation effects on chlorimuron-ethyl-contaminated soil. The chlorimuron-ethyl residues in the soils and the survival condition of strain CHL1(T) were detected. Meanwhile, the shifts of soil microbial catabolic profile were investigated by MicroResp (TM) analysis for the first time. The results indicated that strain CHL1(T) significantly shorten the half-life (6-17 days) of chlorimuron-ethyl and removed 95-100% of chlorimuron-ethyl by the end of the experiment. Meanwhile, the strain CHL1 could inhabit in soil steadily (4.2-4.7 x 10(7) per g dry soil) for a long time. The inoculation with strain CHL1 significantly shorten and relieved the disturbance effects of chlorimuron-ethyl on soil CLPPs. After inoculation with strain CHL1 60 days, the basal respiration rates and Shannon-Wiener indices of groups S10+ and S30+ had recovered to the control level. Even in the high chlorimuron-ethyl-treated groups (S-100), the basal respiration rates and Shannon-Wiener indices were significantly higher in S100+ than that in S100-. These results show the outstanding remediation effects of strain CHL1 and provide new insights into the assessment of the remediation process of chlorimuron-ethyl contaminated soils.