Natural Niche for Organohalide-Respiring Chloroflexi
Natural Niche for Organohalide-Respiring Chloroflexi
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DOI：
10.1128/aem.06510-11
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发表时间：
2012-01-01
影响因子：
4.4
通讯作者：
Novak, Paige J.
中科院分区：
文献类型：
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作者：
Krzmarzick, Mark J.;Crary, Benjamin B.;Novak, Paige J.
氯氟烃门含有几种分离的细菌，这些细菌被发现可以呼吸多种卤化人为化学物质。在未受污染的陆地环境中，大量的天然有机卤素可以作为潜在的电子受体，但这些氯氟西的分布和作用尚未得到研究。我们分析了一系列未受污染地点的土壤样本（共116个，包括6个切片岩心），分析了Dehalococcoides-like chloroflex 16S rRNA基因的存在数量。除13份样本外，其余样本均检出类氯螨种群。测定了67个土壤核心剖面的有机氯、无机氯和总有机碳浓度。dehalococoides -like Chloroflexi 16S rRNA基因数量与[有机氯]/TOC呈正相关，而Bacteria 16S rRNA基因数量与[有机氯]/TOC呈正相关。当与酵素产生的有机氯混合物一起培养时，也观察到类似氯氟的去卤球类的数量增加，同时氯的积累。本研究表明，可呼吸有机卤素的氯氟草胺作为未受污染的陆地生态系统的一部分广泛分布，它们与以有机氯形式存在的TOC比例相关，并且在有机氯脱氯过程中丰度增加。这些发现表明，有机卤化物呼吸氯氟烃可能在生物地球化学氯循环中起着不可或缺的作用。
The phylum Chloroflexi contains several isolated bacteria that have been found to respire a diverse array of halogenated anthropogenic chemicals. The distribution and role of these Chloroflexi in uncontaminated terrestrial environments, where abundant natural organohalogens could function as potential electron acceptors, have not been studied. Soil samples (116 total, including 6 sectioned cores) from a range of uncontaminated sites were analyzed for the number of Dehalococcoides-like Chloroflexi 16S rRNA genes present. Dehalococcoides-like Chloroflexi populations were detected in all but 13 samples. The concentrations of organochlorine ([organochlorine]), inorganic chloride, and total organic carbon (TOC) were obtained for 67 soil core sections. The number of Dehalococcoides-like Chloroflexi 16S rRNA genes positively correlated with [organochlorine]/TOC while the number of Bacteria 16S rRNA genes did not. Dehalococcoides-like Chloroflexi were also observed to increase in number with a concomitant accumulation of chloride when cultured with an enzymatically produced mixture of organochlorines. This research provides evidence that organohalide-respiring Chloroflexi are widely distributed as part of uncontaminated terrestrial ecosystems, they are correlated with the fraction of TOC present as organochlorines, and they increase in abundance while dechlorinating organochlorines. These findings suggest that organohalide-respiring Chloroflexi may play an integral role in the biogeochemical chlorine cycle.