Abstract: Chlorothalonil is the priority organic pollutant listed by the U.S. Environmental Protection Agency. To utilize the function of microbial degradation in the bioremediation of chlorothalonil-contaminated soil is of practical significance. In this study, a chlorothalonil-degrading Pseudomonas sp. strain CTN-3 isolated from pesticide-contaminated soil was used to examine the chlorothalonil- degrading capacity of the strain and related affecting factors in a microcosm. In sterilized soil, the effect of CTN-3 on chlorothalonil degradation was better than that in unsterilized soil. Various factors, including soil pH, temperature, initial chlorothalonil concentration, and inoculum size, affected the degradation of chlorothalonil by the strain. With the inoculum size of 106 CFU·g-1 soil, the CTN-3 at 15-30 ℃ and pH 5.8-8.3 could effectively degrade 10-200 mg·kg-1 of chlorothalonil, suggesting that the strain CTN-3 had great potential in the bioremediation of chlorothalonil-contaminated soil.

Key words: chlorothalonil,  Pseudomonas sp., bioremediation, affecting factor