Key Laboratory of Biogeology and Environmental Geology, Ministry of Education of China, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
J Environ Sci (China). 2009;21(11):1591-7. doi: 10.1016/s1001-0742(08)62460-2.
Profenofos, a well known organophosphate pesticide, has been in agricultural use over the last two decades for controlling Lepidopteron pests of cotton and tobacco crops. In this study, a bacterial strain, OW, was isolated from a long term profenofos exposed soil by an enrichment technique, and its ability to degrade profenofos was determined using gas chromatography. The isolated strain OW was identified as Pseudomonas aeruginosa according to its physiological and biochemical properties, and the analysis of its 16S rRNA gene sequence. The strain grew well at pH 5.5-7.2 with a broad temperature profile. Bioremediation of profenofos-contaminated soil was examined using soil treated with 200 microg/g profenofos, which resulted in a higher degradation rate than control soils without inoculation. In a mineral salt medium (FTW), removal in the level of profenofos of 86.81% was obtained within 48 h of incubation. The intermediates of profenofos metabolism indicated that the degradation occurred through a hydrolysis mechanism, and one of the metabolites was found to be 4 bromo-2-cholorophenol (BCP) which in turn was also mineralized by the strain. The results of this study highlighted the potentiality of P aeruginosa as a biodegrader which could be used for the bioremediation of profenofos contaminated soil.
丙溴磷，一种常用的有机磷农药，在过去的二十年中一直被用于控制棉花和烟草作物鳞翅目害虫。本研究采用富集技术，从长期接触丙溴磷的土壤中分离到一株能够降解丙溴磷的细菌菌株 OW，并通过气相色谱法测定其降解能力。根据生理生化特性和 16S rRNA 基因序列分析，将分离得到的菌株 OW 鉴定为铜绿假单胞菌。该菌株在 pH5.5-7.2 之间、温度范围较宽的条件下生长良好。用含 200μg/g 丙溴磷的土壤进行生物修复试验，结果表明，接种该菌的土壤比未接种的对照土壤具有更高的降解率。在无机盐培养基（FTW）中，培养 48 小时后，丙溴磷的去除率达到 86.81%。丙溴磷代谢的中间产物表明，其降解是通过水解机制进行的，其中一种代谢产物被鉴定为 4-溴-2-氯苯酚（BCP），该化合物也被该菌株矿化。本研究结果表明，铜绿假单胞菌具有作为生物降解剂的潜力，可用于丙溴磷污染土壤的生物修复。
