Dehalococcoides mccartyi Strain DCMB5 Respires a Broad Spectrum of Chlorinated Aromatic Compounds
Dehalococcoides mccartyi Strain DCMB5 Respires a Broad Spectrum of Chlorinated Aromatic Compounds
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DOI：
10.1128/aem.02597-14
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发表时间：
2014-11
影响因子：
4.4
通讯作者：
Marlén Pöritz;Christian L. Schiffmann;G. Hause;Ulrike Heinemann;J. Seifert;N. Jehmlich;M. von Bergen;I. Nijenhuis;U. Lechner
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文献类型：
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作者：
Marlén Pöritz;Christian L. Schiffmann;G. Hause;Ulrike Heinemann;J. Seifert;N. Jehmlich;M. von Bergen;I. Nijenhuis;U. Lechner
摘要多卤代芳香族化合物是一种有害的环境污染物，在缺氧的土壤和沉积物中具有持久性。研究了来源于二恶英污染河流底泥的Mccartyi脱卤球菌DCMB 5菌株对多种氯代芳香族化合物的脱卤能力。菌株DCMB 5使用六氯苯、五氯苯、所有三种四氯苯和1，2，3-三氯苯以及1，2，3，4-四-和1，2，4-三氯二苯并-对-二恶英作为有机卤化物呼吸的电子受体。此外，1，2，3-三氯二苯并-对-二恶英以及1，3-、1，2-和1，4-二氯二苯并-对-二恶英也发生了脱氯反应，后者在转移后的1至4天内就转化为非氯化同系物。菌株DCMB 5还对五氯苯酚以及几乎所有的四氯苯酚和三氯苯酚进行脱氯。四氯乙烯脱氯为三氯乙烯，并作为生长的电子受体。与选定的脱氯活动的特定还原脱卤酶基因的表达，1，2，3-三氯苯，五氯苯，和四氯乙烯脱氯文化的蛋白质组进行了分析。Dcmb_86，氯苯还原脱卤酶CbrA的直系同源物，是最丰富的还原脱卤酶生长过程中与每个电子受体，这表明其在有机卤化物呼吸的菌株DCMB 5的关键作用。然而，Dcmb_1041特异性诱导的氯苯，而3个推定的还原脱卤酶，Dcmb_1434，Dcmb_1339，和Dcmb_1383，只在四氯乙烯生长的细胞中检测到。蛋白质组还含有IV型菌毛蛋白及其组装、拆卸和分泌的组分。透射电镜观察显示DCMB 5细胞分裂方式不规则，并有皮利存在，表明菌毛形成是D. mccartyi在有机卤化物呼吸。
ABSTRACT Polyhalogenated aromatic compounds are harmful environmental contaminants and tend to persist in anoxic soils and sediments. Dehalococcoides mccartyi strain DCMB5, a strain originating from dioxin-polluted river sediment, was examined for its capacity to dehalogenate diverse chloroaromatic compounds. Strain DCMB5 used hexachlorobenzenes, pentachlorobenzenes, all three tetrachlorobenzenes, and 1,2,3-trichlorobenzene as well as 1,2,3,4-tetra- and 1,2,4-trichlorodibenzo-p-dioxin as electron acceptors for organohalide respiration. In addition, 1,2,3-trichlorodibenzo-p-dioxin and 1,3-, 1,2-, and 1,4-dichlorodibenzo-p-dioxin were dechlorinated, the latter to the nonchlorinated congener with a remarkably short lag phase of 1 to 4 days following transfer. Strain DCMB5 also dechlorinated pentachlorophenol and almost all tetra- and trichlorophenols. Tetrachloroethene was dechlorinated to trichloroethene and served as an electron acceptor for growth. To relate selected dechlorination activities to the expression of specific reductive dehalogenase genes, the proteomes of 1,2,3-trichlorobenzene-, pentachlorobenzene-, and tetrachloroethene-dechlorinating cultures were analyzed. Dcmb_86, an ortholog of the chlorobenzene reductive dehalogenase CbrA, was the most abundant reductive dehalogenase during growth with each electron acceptor, suggesting its pivotal role in organohalide respiration of strain DCMB5. Dcmb_1041 was specifically induced, however, by both chlorobenzenes, whereas 3 putative reductive dehalogenases, Dcmb_1434, Dcmb_1339, and Dcmb_1383, were detected only in tetrachloroethene-grown cells. The proteomes also harbored a type IV pilus protein and the components for its assembly, disassembly, and secretion. In addition, transmission electron microscopy of DCMB5 revealed an irregular mode of cell division as well as the presence of pili, indicating that pilus formation is a feature of D. mccartyi during organohalide respiration.