[Isolation, identification and degrading gene cloning of a pyrethroids-degrading bacterium]

This study aimed to isolate, identify and clone degrading gene of a synthetic pyrethroids degrading bacterium.

A photosynthetic bacterial strain PSB07-21 capable of degrading several synthetic pyrethroids efficiently was isolated by an enrichment culture. PSB07-21 was identified based on its morphology, physiology and phylogenetic analysis of 16S rDNA sequence. The degradation ability of this strain was evaluated with gas chromatography.The degrading gene was cloned with PCR.

PSB07-21 was closely related to Rhodopseudomonas sp. The optimum condition of degrading synthetic pyrethroidss was at 35 degrees C, pH 7 and 3000 lx. PSB07-21 could degrade fenpropathrin, cypermethrin and bipthenthrin by 66.63%, 43.25% and 50.18% in a concentration of 600 mg/L at day 15, respectively. We cloned a putative gene which was 326bp long with 37.0% identical to 20G-Fe (II) oxygenase gene. When compensating low concentration Fe (II) in PSB medium with synthetic pyrethroids, the degradation efficiency of PSB07-21 was enhanced.

The strain has the potential application to synthetic pyrethroids bioremediation.