Aerobic debromination of deca-BDE: Isolation and characterization of an indigenous isolate from a PBDE contaminated sediment

The environmental safety of decabromodiphenyl ether (deca-BDE) has been the topic of controversial discussions during the recent years. Reductive debromination of deca-BDE in the environment was proved to be a significant source of lower-brominated Polybrominated diphenyl ethers (PBDEs) to the ecosystem. Currently, very little is known about the susceptibility of deca-BDE to aerobic biotransformation. Lysinibacillus fusiformis strain DB-1, an aerobic bacterium capable of debromination of deca-BDE, was isolated from sediments of LianjiangRiver, Guiyu in Guangdong of China. DB-1 can efficiently transform deca-BDE to lower brominated BDEs using carbon sources such as lactate, pyruvate and acetate, respectively. In liquid cultures, free bromide concentration accumulated to 1220 μg L^-1 with 6 mg L^-1 of the nominal initial concentration of deca-BDE after 72 h aerobic incubation. The resting cell activity tests showed that debromination of deca-BDE by DB-1 was an aerobic process. This is the first report for biotransformation of deca-BDE by an indigenous bacterium isolated from PBDEs contaminated environment.