Isolation and degradation characteristics of an acetochlor-degrading strain

Abstract:

[Objective] This study was aimed to obtain a strain which can effectively degrade acetochlor, and to investigate the factors affecting the degradation of the herbicide, so as to provide microbial resources for acetocholor bioremediation. [Methods] By enrichment and separation of culture from the sample, the pure culture was selected from the medium supplemented with acetochlor as the sole source of carbon and nitrogen. The strain in single colony was obtained by means of streak, and was preliminarily identified and classified by Gram staining and 16S rRNA gene sequencing. Effects of initial acetochlor concentration, additional sources of carbon and nitrogen on the degradation of the herbicide were studied by single factor test. Meanwhile, the effects of above-mentioned factors were optimized by orthogonal design. [Results] A strain of Gram negative bacteria was isolated and identified as Pseudomonas sp. Single factor experiment demonstrated that the optimal initial acetochlor concentration for acetochlor degradation was 10 mg/L; the addition of carbon and nitrogen sources could improve the degradation rate of acetochlor. Among them, glucose and peptone was the best carbon and nitrogen source, respectively. The orthogonal design showed that the degradation rate of acetochlor could reach 80.2% under the optimum conditions. [Conclusion] The strain A-1 was able to grow on acetochlor, and the degradation of the herbicide is affected by many factors. This study will provide the strain resources for acetochlor bioremediation.