Department of Agricultural Biotechnology and Research Institute for Agriculture and Life sciences, Seoul National University, Seoul, Korea.
FEMS Microbiol Lett. 2013 Jul;344(2):114-20. doi: 10.1111/1574-6968.12163. Epub 2013 May 28.
Two bacterial strains involved in syntrophic degradation of chloroacetamide herbicide butachlor were isolated from a rice paddy soil. Analysis of 16S rRNA gene sequences indicated that the two isolates were related to members of the genera Mycobacterium and Sphingobium, respectively. Thus, a pair consisted of Mycobacterium sp. J7A and Sphingobium sp. J7B could rapidly degrade butachlor (100 mg L(-1)) at 28 °C within 24 h, while each isolate alone was not able to completely degrade butachlor. The isolate Mycobacterium sp. J7A was observed to grow slightly on butachlor, possibly utilizing the alkyl side chain of butachlor as its carbon and energy source, but the isolate Sphingobium sp. J7B alone could not grow on butachlor at all. Gas chromatography-mass spectrometry on catabolic intermediates revealed that the strain J7A produced and accumulated 2-chloro-N-(2,6-diethylphenyl) acetamide (CDEPA) during growth on butachlor. This intermediate was not further degraded by strain J7A, but strain J7B was observed to be able to completely degrade and grow on it through 2,6-diethylaniline (DEA). The results showed that butachlor was completely degraded by the two isolates by syntrophic metabolism, in which strain Mycobacterium sp. J7A degraded butachlor to CDEPA, which was subsequently degraded by strain Sphingobium sp. J7B through DEA.
两株参与氯乙酰胺除草剂丁草胺共代谢降解的细菌菌株从稻田土壤中分离得到。16S rRNA 基因序列分析表明，这两株菌分别与分枝杆菌属和鞘氨醇单胞菌属的成员相关。因此，由分枝杆菌属 J7A 和鞘氨醇单胞菌属 J7B 组成的一对菌株能够在 28°C 下 24 小时内快速降解 100mg/L 的丁草胺，而单独的每一株菌都不能完全降解丁草胺。观察到分枝杆菌属 J7A 菌株在丁草胺上略有生长，可能将丁草胺的烷基侧链用作其碳源和能源，但鞘氨醇单胞菌属 J7B 菌株单独在丁草胺上根本不能生长。对代谢中间产物进行气相色谱-质谱分析表明，菌株 J7A 在生长过程中产生并积累了 2-氯-N-(2,6-二乙基苯基)乙酰胺（CDEPA）。该中间产物不再被菌株 J7A 进一步降解，但观察到菌株 J7B 能够完全降解并在其上生长，通过 2,6-二乙基苯胺（DEA）。结果表明，这两株菌通过共代谢完全降解了丁草胺，其中分枝杆菌属 J7A 将丁草胺降解为 CDEPA，随后鞘氨醇单胞菌属 J7B 通过 DEA 将其进一步降解。
