Department of Land Resources and Environmental Sciences, Montana State University , Bozeman, MT , USA ; Thermal Biology Institute, Montana State University , Bozeman, MT , USA.
Front Microbiol. 2013 Jun 3;4:106. doi: 10.3389/fmicb.2013.00106. eCollection 2013.
Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average ∼53 Mbp/site) were subjected to multiple taxonomic, phylogenetic, and functional analyses. All methods, including G + C content distribution, MEGAN analyses, and oligonucleotide frequency-based clustering, provided strong support for the dominant community members present in each site. Cyanobacteria were only observed in non-sulfidic sites; de novo assemblies were obtained for Synechococcus-like populations at Chocolate Pots (CP_7) and Fischerella-like populations at White Creek (WC_6). Chloroflexi-like sequences (esp. Roseiflexus and/or Chloroflexus spp.) were observed in all six samples and contained genes involved in bacteriochlorophyll biosynthesis and the 3-hydroxypropionate carbon fixation pathway. Other major sequence assemblies were obtained for a Chlorobiales population from CP_7 (proposed family Thermochlorobacteriaceae), and an anoxygenic, sulfur-oxidizing Thermochromatium-like (Gamma-proteobacteria) population from Bath Lake Vista Annex (BLVA_20). Additional sequence coverage is necessary to establish more complete assemblies of other novel bacteria in these sites (e.g., Bacteroidetes and Firmicutes); however, current assemblies suggested that several of these organisms play important roles in heterotrophic and fermentative metabolisms. Definitive linkages were established between several of the dominant phylotypes present in these habitats and important functional processes such as photosynthesis, carbon fixation, sulfur oxidation, and fermentation.
从不同的温泉（YNP）采集了六个光养微生物席群落进行了宏基因组测序和地球化学分析。这项工作的主要目的是确定分布在黄石地热生态系统中的高温光养微生物席群落组成的差异，并确定这些群落中主要生物的代谢特征，这些特征可能与在生态位分化中起重要作用的环境特征相关。来自六个光养社区的随机 shotgun 宏基因组序列（平均每个位点约 53 Mbp）进行了多种分类学、系统发育和功能分析。所有方法，包括 G+C 含量分布、MEGAN 分析和基于寡核苷酸频率的聚类，都为每个位点的主要群落成员提供了强有力的支持。只有在非硫化物位点才观察到蓝细菌；在巧克力锅（CP_7）获得了类似于 Synechococcus 的聚生体，在白河（WC_6）获得了类似于 Fischerella 的聚生体的从头组装。在所有六个样本中都观察到 Chloroflexi 样序列（特别是 Roseiflexus 和/或 Chloroflexus 属），并包含参与细菌叶绿素生物合成和 3-羟基丙酸碳固定途径的基因。在 CP_7 的 Chlorobiales 种群（拟议的 Thermochlorobacteriaceae 科）和 Bath Lake Vista Annex 的贫氧、硫氧化的 Thermochromatium 样（Gamma-proteobacteria）种群（BLVA_20）获得了其他主要的序列组装。需要更多的序列覆盖来建立这些地点（例如，Bacteroidetes 和 Firmicutes）中其他新型细菌的更完整组装；然而，目前的组装表明，这些生物体中的几个在异养和发酵代谢中发挥重要作用。在这些生境中存在的几个优势类群与光合作用、碳固定、硫氧化和发酵等重要功能过程之间建立了明确的联系。
