Degradation of Pyrethroid Optical Isomers by Soil Microorganisms

Abstract

Degradation of cypermethrin (I) and fenvalerate (II) isomers by isolated soil bacteria was examined.Two out of 103 bacterial strains showed little metabolic activity, but the remaining strains all degraded I and II isomers with high substrate specificity.The (1R, trans, c S), (1R, cis, c S) and (1 S, traps, ciS) isomers of I were degraded faster than the other five isomers of I, and the (2R, ctS) isomer of II than the other three isomers of II. Ester hydrolysis was the main route of degradation.Cell-free extracts were prepared from four bacterial strains and fractionated by gel filtration or ion-exchange column chromatography. The enzyme assay showed the presence of several enzyme fractions capable of preferentially degrading the cS isomers, whereas two enzyme fractions degraded the traps isomers faster than the cis isomers.It appears that soil microorganisms have several esterase enzymes that can hydrolyze I and II isomers with high stereospecificity.

Biodegradation of beta-cyfluthrin by Pseudomonas stutzeri strain S1

“…208) proved the cleavage of ester bond by the bacterium resulting in to detoxification of the insecticide. Although recovery of 14 C from the culture broth was over 90% during incubation of cypermethrin, degradation products retaining the ester linkage were not detected (Sakata et al 1992). Major metabolite found in the culture broth was a hydrolysis product (1RS)-cis, trans-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropane carboxylic acid.…”

“…Therefore, an efficient method for detoxification of this compound is needed. There are only few reports on biodegradation of synthetic pyrethroids such as b-cyfluthrin by Trichoderma viride (Saikia & Gopal 2004; and cypermethrin by Pseudomonas fluorescens (Grant & Betts 2003Grant et al 2002;Sakata et al 1992). Preliminary studies with known microorganisms namely Bacillus subtilis, Bacillus polymyxa, Klebsiella planticola and Proteus vulgaris have shown maximum degradation of this compound up to 37.0% (Gopal et al 2002a;Saikia 2003).…”

Biodegradation of Cypermethrin by a newly isolated actinomycetes HU-S-01 from wastewater sludge

“…It is a practical and applicable solution for detoxifying phenols, diesel fuel, azo dyes, anionic surfactants and pesticide in a range of varying conditions whether in fruits, vegetables, river or soil (Grant et al, 2002;Hosseini et al, 2007;Agarry and Solomon, 2008;Babel and Opiso, 2007;Agarry et al,2009;Kebria et al, 2009;Dhanasekaran et al, 2009;Ghasemi et al, 2010). Many efforts have been undertaken to isolate bacteria, capable of biodegradation of synthetic pyrethroid insecticides and a lot of pyrethroid-degrading microorganisms have been isolated from soil and polluted water (Sakata et al,1992;Maloeny et al, 1993;Halden et al,1999;Nirmali et al, 2005;Jilani and Khan, 2006;Tallur et al, 2008;Arulazhagan et al, 2010;Murugesan et al, 2010). Some pyrethroid hydrolase were purified and characterized from fungi, insect and mouse liver (Liang et al, 2005).…”

Separation of Chiral Pyrethroid Pesticides and Application in Pharmacokinetics Research and Human Exposure Assessment

“…Megharaj et al (Megharaj et al, 1989) screened 10 3 strains from the soil which can selectively degrade cypermethrin and fenvalerate and they can degrade different chiral isomers in different rates. Sakata et al (Sakata et al, 1992) screened 10 3 strains from the soil which can selectively degrade cypermethrin and fenvalerate. Under the action of these bacteria, the iscomers of 1R-trans-αS, 1S-cis-αS and 1S-trans-αS in the 8 isomers of the cypermethrin were degraded with great speed, and the remaining 5 isomers were hardly degraded; and the degradation rate of the 2R-αS iscomer of the fenvalerate was significantly greater than the other three.…”