Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses

摘要

There is global concern about the effects of decabromodiphenyl ether (BDE209) on environmental and public health. The molecular properties, biosorption, degradation, accumulation, and cellular metabolic effects of BDE209 were investigated in this study to identify the mechanisms involved in the aerobic biodegradation of BDE209. BDE209 is initially absorbed by wall teichoic acid and N-acetylglucosamine side chains in peptidoglycan, and then, BDE209 is transported and debrominated through three pathways, giving tri-, hepta-, octa-, and nona-bromodiphenyl ethers. The C-C bond energies decrease as the number of bromine atoms on the diphenyl decreases. Polybrominated diphenyl ethers (PBDEs) inhibit protein expression or accelerate protein degradation and increase membrane permeability and the release of Cl-, Na+, NH4 (+), arabinose, proteins, acetic acid, and oxalic acid. However, PBDEs increase the amounts of K+, Mg2+, PO4 (3-), SO4 (2-), and NO3 (-) assimilated. The biosorption, degradation, accumulation, and removal efficiencies when Brevibacillus brevis (1 g L-1) was exposed to BDE209 (0.5 mg L-1) for 7 days were 7.4, 69.5, 16.3, and 94.6 %, respectively.