title: Microbial degradation of decabromodiphenyl ether (DBDE) in soil slurry microcosms.
abstract: Decabromodiphenyl ether (DBDE), which has been identified as an endocrine disrupting compound, is used as brominated flame retardant, and this can result in serious bioaccumulation within ecological systems. The objective of this study was to explore DBDE bioremediation (25 mg/kg) using laboratory scale soil slurry microcosms. It was found that effective biodegradation of DBDE occurred in all microcosms. Various biometabolites were identified, namely polybrominated diphenyl ethers congeners and hydroxylated brominated diphenyl ether. Reductive debrominated products such as tri-BDE to hepta-BDE congeners were also detected, and their total concentrations ranged from 77.83 to 91.07 ng/g. The mechanism of DBDE biodegradation in soil slurry microcosms is proposed to consist of a series of biological reactions involving hydroxylation and debromination. Catechol 2,3-oxygenase genes, which are able to bring about meta-cleavage at specific unbrominated locations in carbon backbones, were identified as present during the DBDE biodegradation. No obvious effect on the ecological functional potential based on community-level physiological profiling was observed during DBDE biodegradation, and one major facultative Pseudomonas sp. (99 % similarity) was identified in the various soil slurry microcosms. These findings provide an important basis that should help environmental engineers to design future DBDE bioremediation systems that use a practical microcosm system. A bacterial-mixed culture can be selected as part of the bioaugmentation process for in situ DBDE bioremediation. A soil/water microcosm system can be successfully applied to carry out ex situ DBDE bioremediation.
authors.affiliation: Department of Microbiology, Soochow University, Shinlin, Taipei, 11102, Taiwan.
authors.forename: Hsi-Ling
authors.initials: HL
authors.lastname: Chou
authors.affiliation: Department of Environmental Engineering, TunNang University, Shenkeng, New Taipei, 22202, Taiwan.
authors.forename: Mei-Yin
authors.initials: MY
authors.lastname: Hwa
authors.affiliation: Department of Environmental Engineering, TunNang University, Shenkeng, New Taipei, 22202, Taiwan.
authors.forename: Yao-Chuan
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Earth and Life Science, University of Taipei, Taipei, 11048, Taiwan.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Chang
authors.affiliation: Department of Microbiology, Soochow University, Shinlin, Taipei, 11102, Taiwan. ytchang@scu.edu.tw.
authors.forename: Yi-Tang
authors.initials: YT
authors.lastname: Chang
mesh_terms: D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005411:Flame Retardants / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D012988:Soil Microbiology
chemical_list: D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; C010902:decabromobiphenyl ether
keywords: Catechol 2,3-oxygenase; Community-level physiological profiling; Decabromodiphenyl ether; Pseudomonas sp.; Soil slurry microcosm