Study on Combination and Bioremediation of Chlorimuron-ethyl-degrading Strains

The degradation capacity of the four chlorimuron-ethyl-degrading strains, D310-1, LCY-2, LCY-3 and LCY-4, which identified as Rhodococcus sp.,Stenotrophomonas maltophilia sp,Bacillus subtilis sp., and Rhodotorula mucilaginosa sp., respectively, combined in different ways was examined in this study. Then the optimal degradation conditions and mitigation phytotoxicity of chlorimuron-ethyl on sensitive crop were investigated by both orthogonal test and pot culture experiment. The experimental results showed that the combination of four strains was adopted, and the removal rate of chlorimuron-ethyl reached the maximum of 90% in 30 days. Then the optimal degradation conditions were inoculum size 2.5%, temperature 28 degrees C, pH 7.0 and the soil moisture 35%, and the mixed strains could eradicate 92.57% of chlorimuron-ethyl within 30 days. Furthermore pot culture experiment indicated that inoculation of mixed strains could also mitigate the phytotoxic effects of chlorimuron-ethyl on the growth of cucumber seedling.