Genomic resolution of a cold subsurface aquifer community provides metabolic insights for novel microbes adapted to high CO2 concentrations
Genomic resolution of a cold subsurface aquifer community provides metabolic insights for novel microbes adapted to high CO2 concentrations
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DOI：
10.1111/1462-2920.13362
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发表时间：
2017-02-01
影响因子：
5.1
通讯作者：
Banfield, Jillian F.
中科院分区：
文献类型：
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作者：
Probst, Alexander J.;Castelle, Cindy J.;Banfield, Jillian F.
与许多深层地下环境一样，地下高CO2生态系统中的微生物群落仍然相对未被探索。最近的调查基于单基因测定揭示了一个显着的各种各样的生物体从很少研究门在水晶间歇泉（犹他州，美国），一个网站，深源CO2饱和的流体在表面喷发。为了提供这些生物体代谢的基因组分辨率，我们使用了一种新的宏基因组学方法，从隶属于46个不同门级谱系的150种微生物中恢复了227个高质量的基因组。来自两个新的门级谱系的细菌具有固定CO2的能力。在所有研究的生物体的碳固定途径的分析表明，伍德-永达尔途径和卡尔文-本森-Bassham循环发生的频率最高，而反向TCA循环很少使用。我们推断，这一点，并选择II型RuBisCO，是适应高CO2浓度。然而，许多自养生物也可以混合营养生长，这是一种赋予代谢多样性的策略。将156种氢化酶分配给90种不同的生物表明，即使在气态CO2饱和的情况下，H-2也是一种重要的物种间能量货币。总的来说，在生物体水平的代谢分析提供了深入了解的生化循环，支持地下生活在极端条件下的二氧化碳饱和。
As in many deep underground environments, the microbial communities in subsurface high-CO2 ecosystems remain relatively unexplored. Recent investigations based on single-gene assays revealed a remarkable variety of organisms from little studied phyla in Crystal Geyser (Utah, USA), a site where deeply sourced CO2-saturated fluids are erupted at the surface. To provide genomic resolution of the metabolisms of these organisms, we used a novel metagenomic approach to recover 227 high-quality genomes from 150 microbial species affiliated with 46 different phylum-level lineages. Bacteria from two novel phylum-level lineages have the capacity for CO2 fixation. Analyses of carbon fixation pathways in all studied organisms revealed that the Wood-Ljungdahl pathway and the Calvin-Benson-Bassham Cycle occurred with the highest frequency, whereas the reverse TCA cycle was little used. We infer that this, and selection for form II RuBisCOs, are adaptions to high CO2-concentrations. However, many autotrophs can also grow mixotrophically, a strategy that confers metabolic versatility. The assignment of 156 hydrogenases to 90 different organisms suggests that H-2 is an important inter-species energy currency even under gaseous CO2-saturation. Overall, metabolic analyses at the organism level provided insight into the biochemical cycles that support subsurface life under the extreme condition of CO2 saturation.