Selection for Cu-Tolerant Bacterial Communities with Altered Composition, but Unaltered Richness, via Long-Term Cu Exposure
Selection for Cu-Tolerant Bacterial Communities with Altered Composition, but Unaltered Richness, via Long-Term Cu Exposure
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DOI：
10.1128/aem.01071-12
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发表时间：
2012-10-01
影响因子：
4.4
通讯作者：
Nybroe, Ole
中科院分区：
文献类型：
--
作者：
Berg, Jeanette;Brandt, Kristian K.;Nybroe, Ole
有毒金属污染影响土壤细菌群落的组成和金属耐受性。然而，实际上对特定细菌类群（例如门或纲）成员对金属毒性的反应一无所知，并且关于金属对操作分类单位（OTU）丰富度的影响也得到了相互矛盾的结果。我们使用 16S rRNA 基因的标签编码焦磷酸测序来阐明铜 (Cu) 对细菌群落组成和多样性的影响，在一个明确描述的 Cu 梯度（20 至 3,537 mu g g(-1)）内，该梯度源于 85 多年前 CuSO4 的工业污染。 DNA 序列信息与污染引起的群落对铜的耐受性 (PICT) 分析（通过 [H-3]亮氨酸掺入技术测定）以及土壤的化学特征相关。根据 Cu 特异性生物发光生物传感器菌株的结果确定，PICT 与生物可利用的 Cu 显着相关，证明了对 Cu 的特定群落反应。几个门或候选门的成员的相对丰度，包括变形菌门、拟杆菌门、疣微菌门、绿屈菌门、WS3 和浮霉菌门，随着生物可利用铜的增加而降低，而优势门的成员放线菌门没有表现出任何反应，而酸杆菌门的成员则表现出丰度显着增加。有趣的是，类别相对丰度的变化经常偏离它们所属门的反应。尽管铜对铜抗性和群落结构有明显影响，但生物可利用铜水平与细菌 OTU 丰富度没有任何相关性（97% 相似水平）。我们的报告强调了几种对铜有反应的细菌类群，从而为未来的研究提供了新的指导方针，旨在探索金属反应类群成员的细菌域。
Toxic metal pollution affects the composition and metal tolerance of soil bacterial communities. However, there is virtually no knowledge concerning the responses of members of specific bacterial taxa (e.g., phyla or classes) to metal toxicity, and contradictory results have been obtained regarding the impact of metals on operational taxonomic unit (OTU) richness. We used tag-coded pyrosequencing of the 16S rRNA gene to elucidate the impacts of copper (Cu) on bacterial community composition and diversity within a well-described Cu gradient (20 to 3,537 mu g g(-1)) stemming from industrial contamination with CuSO4 more than 85 years ago. DNA sequence information was linked to analysis of pollution-induced community tolerance (PICT) to Cu, as determined by the [H-3]leucine incorporation technique, and to chemical characterization of the soil. PICT was significantly correlated to bioavailable Cu, as determined by the results seen with a Cu-specific bioluminescent biosensor strain, demonstrating a specific community response to Cu. The relative abundances of members of several phyla or candidate phyla, including the Proteobacteria, Bacteroidetes, Verrumicrobia, Chloroflexi, WS3, and Planctomycetes, decreased with increasing bioavailable Cu, while members of the dominant phylum, the Actinobacteria, showed no response and members of the Acidobacteria showed a marked increase in abundance. Interestingly, changes in the relative abundances of classes frequently deviated from the responses of the phyla to which they belong. Despite the apparent Cu impacts on Cu resistance and community structure, bioavailable Cu levels did not show any correlation to bacterial OTU richness (97% similarity level). Our report highlights several bacterial taxa responding to Cu and thereby provides new guidelines for future studies aiming to explore the bacterial domain for members of metal-responding taxa.