Ecophysiology of Fe-Cycling Bacteria in Acidic Sediments
Ecophysiology of Fe-Cycling Bacteria in Acidic Sediments
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DOI：
10.1128/aem.01931-10
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发表时间：
2010-12-01
影响因子：
4.4
通讯作者：
Kuesel, Kirsten
中科院分区：
文献类型：
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作者：
Lu, Shipeng;Gischkat, Stefan;Kuesel, Kirsten
使用培养依赖和独立的方法相结合，本研究的目的是阐明参与铁循环的微生物的多样性，并解决其原位功能链接在沉积物中的酸性褐煤矿湖。使用6种不同的介质，pH值范围从2.5到4.3，117菌株，分为38个不同的菌株，包括27个推定的新物种相对于最接近的特征菌株。在分离出的菌株中，22株能够氧化Fe（II），34株能够减少铁（III）中的施韦曼石，占主导地位的氧化铁在这个湖，和21可以做这两个。所有菌株落入Gammaproteobacteria（未知的Dyella样属和Acidithiobacillus-related菌株），从顶部酸性沉积物区（pH 2.8）。厚壁菌门菌株（与芽孢杆菌和脂环芽孢杆菌有关）仅分离自深的中等酸性沉积物区（pH 4至5）。在Alphaproteobacteria中，Acidocella相关菌株仅分离自酸性区，而Acidiphilium相关菌株则分离自所有沉积物深度。细菌克隆文库通常支持和补充这些模式。土细菌相关克隆序列仅从深层沉积物区获得，土细菌特异性定量PCR产生8 × 10（5）个基因拷贝数。与酸杆菌属，酸胞菌属，和Alicyclobacillus属和未知的Dyella样属的菌株表现出广泛的pH耐受性，范围从2.5至5.0，和优选的施威曼铁矿针铁矿Fe（III）还原。这项研究强调了在酸性环境中负责铁循环的嗜酸微生物的种类，扩展了最近基于实验室的研究结果，这些研究表明这种特性在嗜酸菌中广泛存在。
Using a combination of cultivation-dependent and -independent methods, this study aimed to elucidate the diversity of microorganisms involved in iron cycling and to resolve their in situ functional links in sediments of an acidic lignite mine lake. Using six different media with pH values ranging from 2.5 to 4.3, 117 isolates were obtained that grouped into 38 different strains, including 27 putative new species with respect to the closest characterized strains. Among the isolated strains, 22 strains were able to oxidize Fe(II), 34 were able to reduce Fe(III) in schwertmannite, the dominant iron oxide in this lake, and 21 could do both. All isolates falling into the Gammaproteobacteria (an unknown Dyella-like genus and Acidithiobacillus-related strains) were obtained from the top acidic sediment zones (pH 2.8). Firmicutes strains (related to Bacillus and Alicyclobacillus) were only isolated from deep, moderately acidic sediment zones (pH 4 to 5). Of the Alphaproteobacteria, Acidocella-related strains were only isolated from acidic zones, whereas Acidiphilium-related strains were isolated from all sediment depths. Bacterial clone libraries generally supported and complemented these patterns. Geobacter-related clone sequences were only obtained from deep sediment zones, and Geobacter-specific quantitative PCR yielded 8 X 10(5) gene copy numbers. Isolates related to the Acidobacterium, Acidocella, and Alicyclobacillus genera and to the unknown Dyella-like genus showed a broad pH tolerance, ranging from 2.5 to 5.0, and preferred schwertmannite to goethite for Fe(III) reduction. This study highlighted the variety of acidophilic microorganisms that are responsible for iron cycling in acidic environments, extending the results of recent laboratory-based studies that showed this trait to be widespread among acidophiles.