Xu Jun, Qiu Xinghui, Dai Jiayin, Cao Hong, Yang Min, Zhang Jing, Xu Muqi
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuanxi Lu, Haidian, 100080, Beijing, PR China.
Biodegradation. 2006 Jun;17(3):219-25. doi: 10.1007/s10532-005-4220-0.
To date, no pure bacterial cultures that could degrade acetochlor have been described. In this study, one strain of microorganism capable of degrading acetochlor, designated as LCa2, was isolated from acetochlor-contaminated soil. The strain LCa2 is Pseudomonas oleovorans according to the criteria of Bergey's manual of determinative bacteriology and sequence analysis of the partial 16S rRNA gene. Optimum growth temperature and pH were 35 degrees C and 8.0, respectively. The strain could degrade 98.03% of acetochlor treated at a concentration of 7.6 mg l(-1) after 7 days of incubation and could tolerate 200 mg l(-1) of acetochlor. When the acetochlor concentration became higher, the degradation cycle became longer. The acetochlor biodegradation products were identified by GC-MS based on mass spectral data and fragmentation patterns. The main plausible degradative pathways involved dechlorination, hydroxylation, N-dealkylation, C-dealkylation and dehydrogenation.
迄今为止，尚未有能够降解乙草胺的纯细菌培养物被报道。在本研究中，从受乙草胺污染的土壤中分离出了一株能够降解乙草胺的微生物菌株，命名为LCa2。根据《伯杰氏鉴定细菌学手册》的标准和部分16S rRNA基因的序列分析，菌株LCa2为食油假单胞菌。最佳生长温度和pH分别为35℃和8.0。该菌株在培养7天后能够降解浓度为7.6 mg l(-1)的乙草胺的98.03%，并且能够耐受200 mg l(-1)的乙草胺。当乙草胺浓度升高时，降解周期变长。基于质谱数据和碎片模式，通过气相色谱-质谱联用仪（GC-MS）鉴定了乙草胺的生物降解产物。主要可能的降解途径包括脱氯、羟基化、N-脱烷基化、C-脱烷基化和脱氢。
