Prokaryotic and Eukaryotic Community Structure in Field and Cultured Microbialites from the Alkaline Lake Alchichica (Mexico)
Prokaryotic and Eukaryotic Community Structure in Field and Cultured Microbialites from the Alkaline Lake Alchichica (Mexico)
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DOI：
10.1371/journal.pone.0028767
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发表时间：
2011-12-14
期刊：
影响因子：
3.7
通讯作者：
Lopez-Garcia, Purificacion
中科院分区：
文献类型：
--
作者：
Couradeau, Estelle;Benzerara, Karim;Lopez-Garcia, Purificacion
火山口湖微生物岩的地球微生物学在很大程度上仍然未知，尽管它们具有进化意义，因为它们与一些太古宙类似物相似，在原位碳酸盐沉淀中占主导地位。在这里，我们研究了碱性阿尔奇奇卡湖微生物岩中古细菌、细菌和原生生物的多样性，这些样本来自沿深度梯度（0-14 m 深度）收集的现场样本和长期维护的实验室水族箱。使用小亚基 (SSU) rRNA 基因库和指纹识别方法，我们检测到了多种细菌和原生生物，与一小部分古细菌形成鲜明对比。产氧光合细菌以蓝细菌、绿藻和硅藻为主。蓝藻多样性随深度而变化，颤藻菌在浅层和中层微生物岩中占主导地位，侧藻菌在最深的样品中占主导地位。早期分支的胶杆菌目在水族箱微生物中占很大比例。无氧光合作用者也多种多样，包括阿尔法变形菌门和绿柔菌门的成员。尽管光合微生物在生物量上占主导地位，但异养谱系更加多样化。我们检测到了多达 21 个细菌门或候选科的成员，包括可能参与微生物岩形成的谱系，例如硫酸盐还原性 Deltaproteobacteria，而且还包括厚壁菌门和可能能够降解复杂聚合物的多种类群，例如 Planctomycetales、Bacteroidetes 和 Verrucomicrobia。异养真核生物以真菌（包括基部 Rozellida 或隐菌门的成员）、领鞭毛纲、核纲、变形虫纲、泡孔纲和原生藻纲为主。许多真核生物谱系的多样性和相对丰度表明原生生物在微生物生态学中发挥着不可预见的作用。许多来自湖泊微生物的谱系在水族馆中被成功保存。有趣的是，在水族箱微生物中检测到的多样性高于野外样本，这可能是由于更稳定和有利的实验室条件。在实验室水族箱中维持高度多样化的天然微生物有望在受控条件下研究不同代谢在这些结构形成中的作用。
The geomicrobiology of crater lake microbialites remains largely unknown despite their evolutionary interest due to their resemblance to some Archaean analogs in the dominance of in situ carbonate precipitation over accretion. Here, we studied the diversity of archaea, bacteria and protists in microbialites of the alkaline Lake Alchichica from both field samples collected along a depth gradient (0-14 m depth) and long-term-maintained laboratory aquaria. Using small subunit (SSU) rRNA gene libraries and fingerprinting methods, we detected a wide diversity of bacteria and protists contrasting with a minor fraction of archaea. Oxygenic photosynthesizers were dominated by cyanobacteria, green algae and diatoms. Cyanobacterial diversity varied with depth, Oscillatoriales dominating shallow and intermediate microbialites and Pleurocapsales the deepest samples. The early-branching Gloeobacterales represented significant proportions in aquaria microbialites. Anoxygenic photosynthesizers were also diverse, comprising members of Alphaproteobacteria and Chloroflexi. Although photosynthetic microorganisms dominated in biomass, heterotrophic lineages were more diverse. We detected members of up to 21 bacterial phyla or candidate divisions, including lineages possibly involved in microbialite formation, such as sulfate-reducing Deltaproteobacteria but also Firmicutes and very diverse taxa likely able to degrade complex polymeric substances, such as Planctomycetales, Bacteroidetes and Verrucomicrobia. Heterotrophic eukaryotes were dominated by Fungi (including members of the basal Rozellida or Cryptomycota), Choanoflagellida, Nucleariida, Amoebozoa, Alveolata and Stramenopiles. The diversity and relative abundance of many eukaryotic lineages suggest an unforeseen role for protists in microbialite ecology. Many lineages from lake microbialites were successfully maintained in aquaria. Interestingly, the diversity detected in aquarium microbialites was higher than in field samples, possibly due to more stable and favorable laboratory conditions. The maintenance of highly diverse natural microbialites in laboratory aquaria holds promise to study the role of different metabolisms in the formation of these structures under controlled conditions.