Abstract: To investigate the degradation characteristics of decabromodiphenyl ether (BDE-209) by bacteria, an effective aerobic bacterium for degrading of BDE-209 was isolated from activated sludge and identified as Pseudomonas nitroreducens. The optimal additional carbon sources for the biodegradation of BDE-209 were investigated, and the changes of cell surface characteristics and degradation kinetics at different initial mass concentrations of BDE-209 by P. nitroreducens were explored. The experimental results showed that P. nitroreducens was able to grow with BDE-209 as the sole carbon source. Glucose played a significant role in promoting the biodegradation of BDE-209, and the degradation rate of 10 mg/L BDE-209 could reach 76.2% when the glucose mass concentration was 250 mg/L. The degradation kinetics of BDE-209 was in accordance with pseudo first order reaction kinetic equation with short half-life and fast degradation rate. Moreover, P. nitroreducens had a good tolerance to higher mass concentration of BDE-209. High mass concentration of Cu2+ (≥30 mg/L) inhibited the degradation of BDE-209 and the growth of P.nitroreducens. The high cell surface hydrophobicity of P.nitroreducens made BDE-209 enter the cells more easily. The increase in cell membrane permeability was caused by the stressful effects of BDE-209. The microbial degradation is an effective remediation strategy to remove BDE-209 from the polluted environment, and the effective screening of degrading bacteria from the environment provided more possibilities for BDE-209 biodegradation.

Key words: BDE-209, biodegradation, degradation kinetics, Cu2+, cell surface characteristics