Biodegradation of beta-cyfluthrin by Pseudomonas stutzeri strain S1

Abstract

b-Cyfluthrin [a-cyano-4-fluoro-3-phenoxybenzyl-3(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate] pesticide has been in agricultural use in the recent years for controlling Lepidopteran pests affecting solanaceous crops. The extensive use of synthetic pyrethroids like b-cyfluthrin has resulted in wide spread environmental contamination. The purpose of this study was to isolate bacteria from soil and to determine their ability to degrade b-cyfluthrin and identify the intermediates in culture broth using spectroscopy. An aerobic bacterium capable of degrading b-cyfluthrin was isolated by enrichment culture. The 16S ribosomal DNAsequence of the isolate (strain S1) had 100% identity to the sequence from Pseudomonas stutzeri. Finally products formed during degradation of b-cyfluthrin have been identified as a-cyano-4-fluoro-3-phenoxybenzyl-3(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate (M.W. 341); 4-fluoro-3-phenoxy-a-cyanobenzyl alcohol(M.W. 243) and (2,2-dichlorovinyl)-2,2-dimethyl cyclopropanecarboxylic acid(M.W. 208).