Abstract

Microbial mats are stratified systems of microorganisms that have served as models to study diverse ecological functions. Comparing the unique and shared characteristics between different microbial mats could shed new light on the biodiversity, functionality and genetic potential of these habitats. In this study, the taxonomic diversity of a microbial mat from the Araro hot springs (Trans-Mexican volcanic belt) was explored and compared with the metagenomes of microbial mats from Cuatro Ciénegas (Mexico), Guerrero Negro (Mexico), Shark Bay (Australia), Yellowstone (USA), and Diamond Fork (USA). The thermal Araro microbial mat was dominated by the phyla Chloroflexi (particularly Chloroflexus), Cyanobacteria, and Proteobacteria. Chlorobium was abundant at Diamond Fork; whereas Thermus, Synechococcus, and Bacillus were found at the remaining locations together with less abundant microbial groups. Alpha diversity indices were highest in Araro, Cuatro Ciénegas, and Shark Bay. Principal component analysis and hierarchical clustering separated Araro from the remaining microbial mats. SEED subsystems revealed carbohydrate metabolism, amino acids, and derivatives to be dominant functions in most mats, while protein and DNA metabolism were prevalent in Araro. Sequences related to biogeochemical cycles of N, Fe, C, O, and S were observed in all mats except Yellowstone (O cycle only), suggesting the presence of different trophic groups. In summary, the six metagenomes exhibit important taxonomic and functional differences, which could be related to their environmental and physicochemical adaptations.

摘要

微生物垫是微生物的分层系统，已作为研究不同生态功能的模型。比较不同微生物垫之间的独特和共享特征可以为这些栖息地的生物多样性、功能和遗传潜力提供新的线索。在这项研究中，探索了来自 Araro 温泉（跨墨西哥火山带）的微生物垫的分类多样性，并与来自 Cuatro Ciénegas（墨西哥）、Guerrero Negro（墨西哥）、鲨鱼湾（澳大利亚）的微生物垫的宏基因组进行了比较）、黄石公园（美国）和钻石叉（美国）。热 Araro 微生物垫由 Chloroflexi 门（特别是Chloroflexus）、蓝细菌和变形菌主导。Diamond Fork富含氯；然而栖热菌、集聚球菌和芽孢杆菌在其余位置发现了较少的微生物群。Araro、Cuatro Ciénegas 和 Shark Ba​​y 的 Alpha 多样性指数最高。主成分分析和层次聚类将 Araro 与剩余的微生物垫分开。SEED 子系统显示碳水化合物代谢、氨基酸和衍生物是大多数垫子的主要功能，而蛋白质和 DNA 代谢在 Araro 中普遍存在。在除黄石公园（仅 O 循环）外的所有垫子中均观察到与 N、Fe、C、O 和 S 的生物地球化学循环相关的序列，表明存在不同的营养组。总之，六个宏基因组表现出重要的分类和功能差异，这可能与它们的环境和物理化学适应有关。