Microbial Biotechnology Laboratory, School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu, India.
Lett Appl Microbiol. 2013 Dec;57(6):510-6. doi: 10.1111/lam.12141. Epub 2013 Aug 22.
Paddy field soil with prior exposure to chlorpyrifos was chosen for the biodegradation of the pesticide by employing bacteria with special emphasis given to actinomycetes. Actinomycetes are organisms predominantly known for their bioactive compounds, but there is dearth of work pertaining to their role in bioremediation. So this work was carried out to screen for actinomycetes and assess their potential in degradation of the pesticide. Actinobacterial strains were isolated from paddy field soil, with capabilities to degrade chlorpyrifos and its major metabolite 3,5,6-trichloro-2-pyridinol (TCP). Two strains were successfully isolated among which one strain was efficient and was able to tolerate high concentrations of chlorpyrifos. This strain was selected for further investigation; it was identified as Gordonia sp based on 16S rRNA analysis and designated as Gordonia sp JAAS1. The actinobacterial strain was able to degrade 110 mg l(-1) of chlorpyrifos within 24 h incubation, and TCP was found to accumulate in the culture medium. However, after 72 h of incubation, TCP was degraded, and finally, diethylthiophosphoric acid (DETP) was obtained.
Biodegradation of chlorpyrifos results in the formation of an antimicrobial compound 3,5,6-trichloro-2-pyridinol (TCP). It is more mobile compared with the parent molecule due to its higher water solubility thus, causing widespread contamination and has antimicrobial property. Therefore, biodegradation of TCP, the major metabolite of chlorpyrifos, is crucial as if left to accumulate, it will kill all the beneficial microbes in the soil. In this study, Streptomyces belonging to genus Gordonia sp JAAS1 strain capable of degrading not only chlorpyrifos but also TCP was observed. This is a first report pertaining to biodegradation of chlorpyrifos and its metabolite TCP from Gordonia genus. The ability to degrade chlorpyrifos and its metabolite TCP makes this strain a useful candidate for the remediation of contaminated sites.
选用先前接触过毒死蜱的稻田土壤，通过使用具有特殊强调放线菌的细菌来进行农药的生物降解。放线菌主要以其生物活性化合物而闻名，但在生物修复方面的工作却很少。因此，进行了这项工作，以筛选放线菌并评估其在农药降解中的潜力。从稻田土壤中分离出具有降解毒死蜱及其主要代谢物 3,5,6-三氯-2-吡啶醇（TCP）能力的放线菌菌株。成功分离出两种菌株，其中一种菌株效率高，能够耐受高浓度的毒死蜱。该菌株被选为进一步研究；基于 16S rRNA 分析，它被鉴定为 Gordonia sp，并被命名为 Gordonia sp JAAS1。该放线菌菌株能够在 24 小时孵育内降解 110mg/L 的毒死蜱，并且在培养基中发现 TCP 积累。然而，在 72 小时孵育后，TCP 被降解，最终获得二乙基硫代磷酸（DETP）。
毒死蜱的生物降解会形成一种抗菌化合物 3,5,6-三氯-2-吡啶醇（TCP）。由于其较高的水溶性，与母体分子相比，它更具流动性，因此造成广泛的污染并具有抗菌特性。因此，降解毒死蜱的主要代谢物 TCP 非常重要，如果任由其积累，它将杀死土壤中所有有益的微生物。在这项研究中，观察到属于 Gordonia sp JAAS1 菌株的链霉菌不仅能够降解毒死蜱，还能够降解 TCP。这是有关 Gordonia 属降解毒死蜱及其代谢物 TCP 的首次报道。降解毒死蜱及其代谢物 TCP 的能力使该菌株成为污染场地修复的有用候选物。
