Cell changes and differential proteomic analysis during biodegradation of decabromodiphenyl ether (BDE-209) by Pseudomonas aeruginosa

Decabromodiphenyl ether (BDE-209) is a brominated flame retardant widely used in the world which, being an emerging persistent organic pollutant, poses a great potential hazard to both human health and the ecological environment. Microbial biodegradation has been considered as an effective and environment-friendly technique to remediate BDE-209. Pseudomonas aeruginosa, a Gram-negative bacterium capable of degrading BDE-209, was isolated from PBDEs-contaminated soil. To promote microbial biodegradation of BDE-209 and gain further insight into its mechanism, cell changes and differential proteomic analysis of P. aeruginosa during biodegradation were studied. The results showed that high cell surface hydrophobicity of P. aeruginosa make the bacteria absorb BDE-209 more easily. The increase in cell membrane permeability was caused by the P. aeruginosa responding to BDE-209 stress. IR spectra showed that hydroxyl, amide and CH groups in the P. aeruginosa cell surface were involved in the interactions between BDE-209 with P. aeruginosa. The apoptotic-like cell changes and cell surface morphology changes were observed by flow cytometry (FCM) and field emission scanning electron microscopy (FESEM), respectively. Differentially expressed protein was analysed by two-dimensional electrophoresis (2-DE) and 40 protein spots were identified to be different after 5 days biodegradation.