Li Lin, Yang Chao, Lan Wensheng, Xie Shan, Qiao Chuanling, Liu Junxin
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Environ Sci Technol. 2008 Mar 15;42(6):2136-41. doi: 10.1021/es702631x.
Methyl parathion (MP), a highly toxic organophosphorus pesticide, was widely used for agriculture crop protection. During the production of MP and the process of MP-containing wastewater treatment, MP can release into the atmosphere and will do great harm to adjacent communities. A consortium comprised of an engineered microorganism and a natural p-nitrophenol (PNP) degrader was assembled for complete mineralization of MP. We genetically engineered Escherichia coli BL21 (DE3) enabling the overexpression of methyl parathion hydrolase (MPH). In addition, we isolated Ochrobactrum sp. strain LL-1 that utilized PNP, a product of MP hydrolysis, as the sole carbon, nitrogen, and energy source. The coculture effectively hydrolyzed 0.2 mM MP and prevented the accumulation of PNP in suspended culture. A laboratory-scale bioreactor containing the dual-species consortium was developed for the treatment of artificial off-gas containing MP. The bioreactor maintained over 98% of average MP removal efficiency over a 75 day period, and PNP produced from hydrolysis of MP was degraded completely, indicating that complete mineralization of MP was achieved. The strategy of linking degrading consortium to a bioreactor may provide an alternative to physicochemical abatement technologies for the treatment of waste-gas streams containing MP as well as other PNP-substituted organophosphates.
甲基对硫磷（MP）是一种剧毒有机磷农药，曾被广泛用于农作物保护。在MP的生产过程以及含MP废水的处理过程中，MP会释放到大气中，对周边社区造成极大危害。构建了一个由工程微生物和天然对硝基苯酚（PNP）降解菌组成的混合菌群，用于MP的完全矿化。我们对大肠杆菌BL21（DE3）进行基因工程改造，使其过量表达甲基对硫磷水解酶（MPH）。此外，我们分离出了嗜油 Ochrobactrum 菌LL-1菌株，它能利用MP水解产物PNP作为唯一的碳源、氮源和能源。该共培养体系能有效水解0.2 mM的MP，并防止悬浮培养中PNP的积累。开发了一个含有双物种混合菌群的实验室规模生物反应器，用于处理含MP的人工废气。在75天的时间里，该生物反应器对MP的平均去除效率保持在98%以上，MP水解产生的PNP被完全降解，这表明实现了MP的完全矿化。将降解混合菌群与生物反应器相结合的策略，可能为处理含MP以及其他PNP取代有机磷酸盐的废气流提供一种替代物理化学减排技术的方法。
