Bioaugmentation degradation of 2,4,6-tribromophenol with the bacterial microcosms from e-waste polluted river sediments by Bacillus sp. GZT

2,4,6-Tribromophenol (TBP) is a pesticide with fungicide activity, presently used as a replacement of pentachlorophenol as a wood preservative and as a flame retardant in electronic and electric devices, and has been... [ view full abstract ]

2,4,6-Tribromophenol (TBP) is a pesticide with fungicide activity, presently used as a replacement of pentachlorophenol as a wood preservative and as a flame retardant in electronic and electric devices, and has been frequently detected in various matrices including water, soil, sediment, and groundwater. In this study, microcosms with different conditions were constructed to investigate the biodegradation of TBP and the evolution of microbial community. The results showed that, as compared with the unamended controls, the bioaugmentation with Bacillus sp. GZT can effectively enhance TBP degradation, with approximately 40.7% of TBP removal after seven weeks incubation without lag phase (p＜0.01). While in unamended controls, the biodegradation of TBP was not obvious. Amendment with 2-bromophenol (2-BP), 2,6-dibromophenol (2,6-DBP) and 2,4-dibromophenol (2,4-DBP) did not promoted rapid biodegradation of TBP in the river sediment (p＞0.05). However, the TBP biodegradation was enhanced by adding sodium chloride, humic acid, sodium lactate and sodium propionate alone, especially glucose and yeast extract. Metagenomic analysis of the total 16S rRNA genes from the treatment system with bioaugmentation showed that four phylums including Proteobacteria (52.08-66.22%), Actinobacteria (20.03-5.47%), Bacteroidetes (6.68-13.68%) and Firmicutes (4.53-20.83%) were found to be the dominant microbial species. This study may provide the possibility to use bioaugmentation with Bacillus sp. GZT to develop cost-effective approaches to eliminate TBP in the water and sediment environments.