Complete Debromination of Tetra- and Penta-Brominated Diphenyl Ethers by a Coculture Consisting of Dehalococcoides and Desulfovibrio Species
Complete Debromination of Tetra- and Penta-Brominated Diphenyl Ethers by a Coculture Consisting of Dehalococcoides and Desulfovibrio Species
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DOI：
10.1021/es201559g
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发表时间：
2011-10-01
影响因子：
11.4
通讯作者：
He, Jianzhong
中科院分区：
文献类型：
--
作者：
Lee, Lip Kim;Ding, Chang;He, Jianzhong
多溴联苯醚（PBDEs）是一种广泛使用的阻燃剂，是全球性的污染物。在209种多溴二苯醚同系物中，四溴二苯醚（同系物47）和五溴二苯醚（同系物99和100）是环境中含量最多、毒性最强和生物累积性最强的同系物。然而，人们对在厌氧条件下对这些同系物进行脱溴的微生物知之甚少。在这项研究中，我们描述了一种由脱卤球菌和脱硫弧菌组成的共培养物GY 2，其脱溴能力类似于1180 nM同系物47、99和100（去除率为88-100%），平均速率分别为36.9、19.8和21.9 nM/天（-1）。在脱溴过程中，邻溴优先被去除。Dehalococcoides的生长与多溴二苯醚的脱溴作用密切相关，估计每释放一摩尔溴，其生长量为1.99 x 10（14）个细胞，而脱硫弧菌的生长可能与多溴二苯醚无关。生长耦合脱溴表明，脱卤球菌细胞在共培养物GY 2能够对多溴二苯醚呼吸。鉴于四溴二苯醚和五溴二苯醚的普遍性和可降解性，将这些同系物完全脱溴为毒性较低的最终产品（如二苯醚）对于恢复受多溴二苯醚污染的环境至关重要。
Polybrominated diphenyl ethers (PBDEs) are widespread global contaminants due to their extensive usage as flame retardants. Among the 209 PBDE congeners, tetrabrominated 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 similar to 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 x 10(14) 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.