Comparison of the PAHs biodegradation rate for microbial consortia

Abstract

The removal efficiency of benzo[a]pyrene (BaP) were compared between two microbial consortia, the one (Con A) consists of a BaP degrading bacterium US6-1 and seven PAHs degraders, and the other (Con B) consists of a strain US6-1 and ten resin compounds degraders. Flasks inoculated with only a strain US6-1 served as a positive control. The BaP degradation rates of Con A after 1 week were 55.9% where 5 ppm of BaP was given as a single pollutant and 35% where 5 ppm of pyrene was coexisted and those of Con B were 68.7% and 51.1%, respectively. However the degradation rates of positive control represented 65.2% (BaP only) and 2.4% (BaP + pyrene). Although BaP degradation rates of Con A and B in the presence of BaP only were not significantly different from that of control, the degradation rates of two consortia were obviously higher than that of control when BaP and pyrene were coexisted. From the results, it could be concluded that bacterial consortium is more efficient than a single strain to remove BaP when the pollutant existed as a mixed state. Further studies on the consortium are necessary to understand the mechanism of bacterial interaction.