Cloning, Expression And Characterization Study Of Fenpropathrin Degradation Genes From Rhodopseudomonas Palustris

Fenpropathrin is one of synthetic pyrethroids with the merits of high activity and long-duration of killing pest, and broad-spectrum, as well as stubbornness in environment. The great concern of contamination on its residue was increasing following with the enormous utilization in field. Microbial remediation is an potential alternatively technology for cleaning the residues of fenpropathrin.The pristine fenpropathrin degrading bacteria Rhodopseudomonas palustris PSB-S was employed in this study. Three potential fenpropathrin-degrading gene (named as Est3384, Est3385 and Est3706) were cloned from strain PSB-S based on homology analysis and draft genomic sequence of strian PSB-S. Amino acid sequences analysis showed degrading proteins Est3384, Est3385 and Est3706 were as member of family I, VII and II of esterase super family, respectively. These three degreding genes were cloned and inserted into prokaryotic expression vector pGEX-3X to generated recombinant vectors of pGEX-3x-3384, pGEX-3x-3385 and pGEX-3x-3706, which prokaryotic expressed recombinant degrading proteins Est3384, Est3385 and Est3706. The optimal conditions for prokayrotic expressing were 35? and 0.7 mM IPTG. The specific recombinant degrading proteins (with GST tag) were successful expressed (all about 55 kDa) and verified by Western blotting with GST-specific antibody.These three recombinant degrading proteins were prokaryotic expressed and purified by affinity chromatography. The degrading characteristics of these three degrading proteins were tested. The optimal conditions for degrading fenpropathrin by these three degrading protein were 35? and pH 7.0. These three degrading proteins could degrade all 7 tested pyrethroids, and the optimal substrates for Est3385 is fenpropathrin, and for Est3384 and Est3706 is ethofenprox except fenpropathrin. These three proteins were all severely inhibited by metal ion, but not inhibited by chemicals as surfactant agents and metal chelators.The results of this study provided a scientific contribution for fenpropathrin's bioremediation, and also provided an novel resources for generating genetic bacteria for fenpropathrin residue remediation.