Lee Sangjin, Gan Jianying, Kim Jong-Sik, Kabashima John N, Crowley David E
Department of Environmental Sciences, University of California-Riverside, Riverside, California 92521, USA.
Environ Toxicol Chem. 2004 Jan;23(1):1-6. doi: 10.1897/03-114.
Recent studies showed that synthetic pyrethroids (SPs) can move via surface runoff into aquatic systems. Fifty-six of SP-degrading bacteria strains were isolated from contaminated sediments, of which six were evaluated for their ability to transform bifenthrin and permethrin in the aqueous phase and bifenthrin in the sediment phase. In the aqueous phase, bifenthrin was rapidly degraded by strains of Stenotrophomonas acidaminiphila, and the half-life (t1/2) was reduced from >700 h to 30 to 131 h. Permethrin isomers were degraded by Aeromonas sobria, Erwinia carotovora, and Yersinia frederiksenii. Similar to bifenthrin, the t1/2 of cis- and trans-permethrin was reduced by approximately 10-fold after bacteria inoculation. However, bifenthrin degradation by S. acidaminiphila was significantly inhibited in the presence of sediment, and the effect was likely caused by strong adsorption to the solid phase. Bifenthrin t1/2 was 343 to 466 h for a field sediment, and increased to 980 to 1200 h for a creek sediment. Bifenthrin degradation in the inoculated slurry treatments was not greatly enhanced when compared with the noninoculated system. Therefore, although SP-degrading bacteria may be widespread in aquatic systems, adsorption to sediment could render SPs unavailable to the degraders, thus prolonging their persistence.
最近的研究表明，合成拟除虫菊酯（SPs）可通过地表径流进入水生系统。从受污染的沉积物中分离出56株SP降解细菌菌株，其中6株被评估了在水相中转化联苯菊酯和氯菊酯以及在沉积物相中转化联苯菊酯的能力。在水相中，嗜氨基寡养单胞菌菌株能快速降解联苯菊酯，半衰期（t1/2）从>700小时降至30至131小时。氯菊酯异构体可被温和气单胞菌、胡萝卜软腐欧文氏菌和费氏耶尔森菌降解。与联苯菊酯类似，接种细菌后顺式和反式氯菊酯的t1/2降低了约10倍。然而，在有沉积物存在的情况下，嗜氨基寡养单胞菌对联苯菊酯的降解受到显著抑制，这种影响可能是由于对联苯菊酯的强烈吸附作用导致的。对于田间沉积物，联苯菊酯的t1/2为343至466小时，而对于小溪沉积物，该值增加到980至1200小时。与未接种系统相比，接种泥浆处理中联苯菊酯的降解并没有显著增强。因此，尽管SP降解细菌可能在水生系统中广泛存在，但沉积物的吸附作用可能会使SPs无法被降解菌利用，从而延长它们的持久性。
