Comparative Metagenomics of Two Microbial Mats at Cuatro Cienegas Basin II: Community Structure and Composition in Oligotrophic Environments
Comparative Metagenomics of Two Microbial Mats at Cuatro Cienegas Basin II: Community Structure and Composition in Oligotrophic Environments
复制标题
DOI：
10.1089/ast.2011.0724
复制
发表时间：
2012-07-01
期刊：
影响因子：
4.2
通讯作者：
Souza, Valeria
中科院分区：
文献类型：
--
作者：
Bonilla-Rosso, German;Peimbert, Mariana;Souza, Valeria
微生物垫是一种自我维持的、功能复杂的生态系统，是理解过去和现在微生物生态系统以及假定的外星生态系统的良好模型。生态学理论表明，这些社区的组成可能会受到营养物质的供应和干扰频率。我们的特点是两个微生物垫从两个对比的环境中贫营养的Cuatro Cienegas盆地：一个永久的绿色池和红色干燥池。我们通过16S rRNA克隆文库和宏基因组学分析了它们的分类结构和组成，并通过分析最丰富的生物体中的功能性状来推断它们的代谢作用。这两个垫子表现出高度的多样性与代谢不同的成员和强烈不同的结构和组成。绿色草席的物种丰富度和均匀度均高于红色草席，红色草席以假单胞菌属（Pseudomonas）为主。在绿色垫中有大量的自养生物，在红色垫中有大量的异养生物。当与其他垫和基质比较时，我们发现分类组成不是在种水平上共享的，而是在目水平上共享的，这表明环境过滤特定生物的随机选择的遗传保守的功能性状。最高的多样性和组成的相似性之间观察到系统稳定的环境，这表明，干扰制度可能会影响多样性更强烈的营养供应，因为寡养不会出现，以防止建立复杂多样的微生物垫社区。这些结果进行了讨论，在寻找外星生命的光。
Microbial mats are self-sustained, functionally complex ecosystems that make good models for the understanding of past and present microbial ecosystems as well as putative extraterrestrial ecosystems. Ecological theory suggests that the composition of these communities might be affected by nutrient availability and disturbance frequency. We characterized two microbial mats from two contrasting environments in the oligotrophic Cuatro Cienegas Basin: a permanent green pool and a red desiccation pond. We analyzed their taxonomic structure and composition by means of 16S rRNA clone libraries and metagenomics and inferred their metabolic role by the analysis of functional traits in the most abundant organisms. Both mats showed a high diversity with metabolically diverse members and strongly differed in structure and composition. The green mat had a higher species richness and evenness than the red mat, which was dominated by a lineage of Pseudomonas. Autotrophs were abundant in the green mat, and heterotrophs were abundant in the red mat. When comparing with other mats and stromatolites, we found that taxonomic composition was not shared at species level but at order level, which suggests environmental filtering for phylogenetically conserved functional traits with random selection of particular organisms. The highest diversity and composition similarity was observed among systems from stable environments, which suggests that disturbance regimes might affect diversity more strongly than nutrient availability, since oligotrophy does not appear to prevent the establishment of complex and diverse microbial mat communities. These results are discussed in light of the search for extraterrestrial life.