Compound degraded:Tetra-brominated diphenyl ethers
General Description (About POP compound)
Tetra-brominated diphenyl ethers belongs to a wider group of polybrominated diphenyl ethers (PBDEs), a class of organobromine compounds that are used as flame retardants. Tetra-brominated diphenyl ethers have been used in a wide array of products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams,[1] and textiles. They are structurally akin to polychlorinated diphenyl ethers (PCDEs), polychlorinated biphenyls (PCBs) and other polyhalogenated compounds, consisting of two halogenated aromatic rings.
Biodegradation pathway
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Publications
| Abstract | Title | Authors | Article Link |
|---|---|---|---|
| A bacterial isolate, TZ-1, was isolated from contaminated sediment near electronic waste dismantling workshops, Taizhou, China that degraded 2,2?,4,4?-tetrabrominated diphenyl ether (BDE-47). The isolate was identified as Pseudomonas putida sp. with respect to its morphology, biochemical characteristics and 16SrDNA sequence analysis. TZ-1 can use BDE-47 as the sole carbon and energy source for growth in mineral salt medium. The isolate degraded BDE-47 up to 49.96 % of the initially applied concentration of 50 ?g L?1 after 7 days of incubation at 150 rpm, 30°C. Static conditions with pH 6.5 and temperature 30°C were considered to be optimum for BDE-47 biodegradation. Addition of co-substrates promoted cell growth, but decreased the degradation rate for BDE-47. | Aerobic Transformation of BDE-47 by a Pseudomonas putida sp. Strain TZ-1 Isolated from PBDEs-Contaminated Sediment | Xin et al., 2014 | Link |
| Polybrominated diphenyl ethers (PBDEs) are bioaccumulative, toxic and persistent, globally distributed organic chemicals in environment. However, very little is known for their aerobic biodegradation. In this research, 2,2?,4,4?-tetrabromodiphenyl ether (BDE-47) was selected as a model congener of PBDEs to study its aerobic biodegradation. A new BDE-47 degrading strain BFR01 identified as Pseudomonas stutzeri was isolated from polluted soil in a former brominated flame retardant production corporation. Stain BFR01 could utilize BDE-47 as a sole source of carbon and energy, and transformed 97.94% of BDE-47 in two weeks; the biodegradation of BDE-47 fitted well with the first-order kinetics, with the first-order kinetics constant of 0.32 d?1. The biodegradation efficiency of stain BFR01 was higher than other reported PBDEs aerobic degrading bacteria. The biodegradation efficiency achieved maximum at pH 7.0 and 40 °C. The presence of additional carbon sources could enhance the biodegradation efficiency of BDE-47 by 1–6%. Furthermore, no lower brominated diphenyl ethers or biphenyl were detected, suggesting that the pathway of BDE-47 biodegradation by strain BFR01 might not be debromination with lower brominated diphenyl ethers as products. This is the first report of aerobic degradation of BDE-47 by P. stutzeri. | Identification and biodegradation efficiency of a newly isolated 2,2?,4,4?-tetrabromodiphenyl ether (BDE-47) aerobic degrading bacterial strain | Zhang et al., 2013 | Link |
| Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants and have therefore drawn much environmental concern. We aimed to compare aerobic degradation of different PBDE congeners under various treatments and reveal the bacterial community associated with PBDE degradation in sediment. Results of this study indicate that degradation rates of BDE-15 were enhanced 45.1 and 81.3 % with the addition of suspended and microencapsulated Pseudomonas sp., respectively. However, the degradation rates of BDE-28, BDE-47, BDE-99, and BDE-100 did not differ among experimental treatments. Degradation rates of PBDE congeners were in the order of BDE-15?>?BDE-28?>?BDE-47?>?BDE-99?>?BDE-100. Using a pyrosequencing-based metagenomic approach, we found that addition of various treatments altered the microbial community composition in the sediment. Twenty-four bacterial genera associated with degradation of PBDEs; six are the core bacterial genera common among PBDE degraders. The diverse bacterial composition among different PBDE congener degradation indicates different combinations of bacteria involved in degradation of different PBDE congeners. | Bacterial communities associated with aerobic degradation of polybrominated diphenyl ethers from river sediments | Yang et al., 2014 | Link |
| Aerobic biodegradation of 2,2?,4,4?-tetrabrominated diphenyl ether (BDE-47) by Phanerochaete chrysosporium in the presence of Cd2+ was investigated in this study. The results showed that P. chrysosporium could effectively degrade BDE-47, and its extracellular enzyme played an important role in the process of decomposition. BDE-47 biodegradation by fungi was more tolerant than extracellular enzyme in the presence of Cd2+. Also, both of the activity of two typical enzymes, MnP and LiP, descended with ascended Cd2+ concentration. Based on the four mono-hydroxylated PBDEs (5-OH-BDE-47, 4?-OH-BDE-17, 6-OH-BDE-47, and 2?-OH-BDE-28) and two bromophenols (2,4-DBP, 4-BP) detected, three possible degradation pathways were proposed, inferring that BDE-47 was more easily to transform via hydroxylation. With addition of Cd2+, the types of degradation products did not change, merely a variation of the content of these products observed. Meanwhile, the major metabolites of BDE-47, bromophenol compounds, have been found to be transformed or even mineralized by P. chrysosporium quickly, which also helped better explain why the amounts of BDE-47 decomposed did not match with that of the metabolites detected. | Biodegradation of 2,2?,4,4?-tetrabromodiphenyl ether (BDE-47) by Phanerochaete chrysosporium in the presence of Cd2+ | Cao et al., 2017 | Link |
| Polybrominated diphenyl ethers (PBDEs) are widespread global contaminants due to their extensive usage as flame retardants. Among the 209 PBDE congeners, tetra-brominated diphenyl ether (tetra-BDE) (congener 47) and penta-BDEs (congeners 99 and 100) are the most abundant, toxic, and bioaccumulative congeners in the environment. However, little is known about microorganisms that carry out debromination of these congeners under anaerobic conditions. In this study, we describe a coculture GY2 consisting of Dehalococcoides and Desulfovibrio spp., which is capable of debrominating ?1180 nM of congeners 47, 99, and 100 (88–100% removal) to the nonbrominated diphenyl ether at an average rate of 36.9, 19.8, and 21.9 nM day–1, respectively. Ortho bromines are preferentially removed during the debromination process. The growth of Dehalococcoides links tightly with PBDE debromination, with an estimated growth yield of 1.99 × 1014 cells per mole of bromide released, while the growth of Desulfovibrio could be independent of PBDEs. The growth-coupled debromination suggests that Dehalococcoides cells in the coculture GY2 are able to respire on PBDEs. Given the ubiquity and recalcitrance of the tetra- and penta-BDEs, complete debromination of these congeners to less toxic end products (e.g. diphenyl ether) is important for the restoration of PBDE-contaminated environments. | Complete Debromination of Tetra- and Penta-Brominated Diphenyl Ethers by a Coculture Consisting of Dehalococcoides and Desulfovibrio Species | Lee et al., 2011 | Link |
| A microbially facilitated approach was developed to degrade 2, 2?, 4, 4?-tetrabrominated diphenyl ether (BDE-47). This approach consisted of biological production of Fe(II) and H2O2 by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 during the repetitive anoxic/oxic cycles and abiotic production of hydroxyl radical (HO?) with the biologically produced Fe(II) and H2O2 via Fenton reaction. Under the condition tested, BDE-47 did not inhibit the growth of S. oneidensis MR-1. Water soluble Fe(III)-citrate and the solid minerals ferrihydrite [Fe(III)2O3•0.5H2O] and goethite [Fe(III)OOH] were tested in this study. Under anoxic condition, the amounts of Fe(II) produced by S. oneidensis MR-1 varied among the Fe(III)s tested, which decreased in the order of Fe(III)-citrate > ferrihydrite > goethite. Under subsequent oxic condition, H2O2 was produced via O2 reduction by S. oneidensis MR-1. The amounts of H2O2 detected also varied, which decreased in the order of the reactions with Fe(III)-citrate > goethite > ferrihydrite. S. oneidensis MR-1 maintained its ability to produce Fe(II) and H2O2 for up to seven anoxic/oxic cycles. At each end of anoxic/oxic cycle, HO? was detected. The amount of HO? produced decreased in the order of the reactions with ferrihydrite > goethite > Fe(III)-citrate, which was opposite to that of H2O2 detected. Compared to the controls without HO?, the amounts of BDE-47 in the reactions with HO? decreased. The more HO? in the reaction, the less amount of BDE-47 detected. Furthermore, no BDE-47 degradation was observed when HO? was scavenged or ferrihydrite was either omitted or replaced by nitrate. Finally, identification of degradation products, such as hydroxylated BDE-47 and trisBDE, dibromophenol and monobromophenol, suggested that OH-addition and Br-substitution by HO? were the main mechanisms for degrading BDE-47. Collectively, all these results demonstrated for the first time that the Fenton reaction driven by S. oneidensis MR-1 degraded BDE-47 effectively. | Degradation of 2, 2?, 4, 4?-Tetrabrominated diphenyl ether (BDE-47) via the Fenton reaction driven by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 | Peng et al., 2020 | Link |