A humin-dependent Dehalobacter species is involved in reductive debromination of tetrabromobisphenol A.
A humin-dependent Dehalobacter species is involved in reductive debromination of tetrabromobisphenol A.
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DOI：
10.1016/j.chemosphere.2013.05.051
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发表时间：
2013-08
期刊：
影响因子：
8.8
通讯作者：
Chunfang Zhang;Zhiling Li;D. Suzuki;L. Ye;N. Yoshida;A. Katayama
中科院分区：
文献类型：
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作者：
Chunfang Zhang;Zhiling Li;D. Suzuki;L. Ye;N. Yoshida;A. Katayama
四溴双酚A （TBBPA）是目前市场上应用最广泛的溴化阻燃剂。在各种环境样本中都检测到它，越来越多的证据表明它对生物体有毒性作用。在这项研究中，我们报道了在人类存在的情况下将TBBPA脱溴为双酚A的细菌的富集和系统发育鉴定。孵育实验表明，这种脱溴活性需要人素。在tbbpa -脱溴培养中检测的五种化合物中，甲酸酯是最佳的电子供体。16S rRNA基因文库显示，培养物以三个已知的脱卤菌属为主：Dehalobacter、Geobacter和sulfurospirillum。进一步的研究表明，脱盐菌负责TBBPA的脱溴。聚合酶链反应-变性梯度凝胶电泳分析表明，利用TBBPA培养物培养出脱盐菌。此外，在不添加TBBPA的培养中，dehalobacters rRNA基因的拷贝数增加了约2个数量级，而当TBBPA存在时，其拷贝数增加了约4个数量级。孵育实验表明，脱盐细菌的脱溴活性依赖于人类，这表明脱盐细菌的一种新的代谢类型与人类呼吸有关。
Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant on the market. It has been detected in various environmental samples, and a growing body of evidence has demonstrated its toxic effects on living organisms. In this study, we report the enrichment and phylogenetic identification of bacteria that debrominate TBBPA to bisphenol A in the presence of humin. Incubation experiments indicated that humin was required for this debromination activity. Of the five compounds examined for inclusion in the TBBPA-debrominating culture, formate was the optimal electron donor. A 16S rRNA gene library showed that the culture was dominated by three known dehalogenator genera:Dehalobacter,Geobacter, andSulfurospirillum. Further investigation indicated thatDehalobacterwas responsible for the debromination of TBBPA. PCR–denaturing gradient gel electrophoresis analysis showed thatDehalobactergrew in the culture by utilizing TBBPA. Moreover, the copy number of theDehalobacter16S rRNA genes increased by about two orders of magnitude in the cultures without the addition of TBBPA, whereas it increased by approximately four orders of magnitude when TBBPA was present. The incubation experiments showed thatDehalobacterwas reliant on humin for its debromination activity, indicating a new type of metabolism inDehalobacterthat is linked to humin respiration.