Microbialites are usually carbonate‐rich sedimentary rocks formed by the interplay of phylogenetically and metabolically complex microbial communities with their physicochemical environment. Yet, the biotic and abiotic determinants of microbialite formation remain poorly constrained. Here, we analysed the structure of prokaryotic and eukaryotic communities associated with microbialites occurring in several crater lakes of the Trans‐Mexican volcanic belt along an alkalinity gradient. Microbialite size and community structure correlated with lake physicochemical parameters, notably alkalinity. Although microbial community composition varied across lake microbialites, major taxa‐associated functions appeared quite stable with both, oxygenic and anoxygenic photosynthesis and, to less extent, sulphate reduction, as major putative carbonatogenic processes. Despite interlake microbialite community differences, we identified a microbial core of 247 operational taxonomic units conserved across lake microbialites, suggesting a prominent ecological role in microbialite formation. This core mostly encompassed Cyanobacteria and their typical associated taxa (Bacteroidetes, Planctomycetes) and diverse anoxygenic photosynthetic bacteria, notably Chloroflexi, Alphaproteobacteria (Rhodobacteriales, Rhodospirilalles), Gammaproteobacteria (Chromatiaceae) and minor proportions of Chlorobi. The conserved core represented up to 40% (relative abundance) of the total community in lakes Alchichica and Atexcac, displaying the highest alkalinities and the most conspicuous microbialites. Core microbialite communities associated with carbonatogenesis might be relevant for inorganic carbon sequestration purposes.

中文翻译：

---

沿碱度梯度采样的湖相微恶岩的核心微生物群落

微生物微岩通常是富含碳酸盐的沉积岩，是由系统发育和代谢复杂的微生物群落与其理化环境相互作用而形成的。然而，微生物形成的生物和非生物决定因素仍然受到限制。在这里，我们分析了沿碱度梯度发生在跨墨西哥火山带几个火山口湖中的与微辉石相关的原核和真核生物群落结构。微生物的大小和群落结构与湖泊的理化参数有关，特别是碱度。尽管各湖微生物的微生物群落组成各不相同，但主要的与生物分类相关的功能在氧气和缺氧的光合作用以及较少的硫酸盐还原作用下都相当稳定。作为主要的假定成岩过程。尽管湖间微生物的群落差异，我们确定了整个湖微生物中保守的247个操作生物分类单元的微生物核心，表明微生物形成中的重要生态作用。这个核心主要包括蓝藻细菌及其典型的相关类群（拟杆菌属，扁平菌属）和各种产氧的光合细菌，特别是绿弯曲菌，α-变形细菌（Rhodobacteriales，Rhodospirilalles），γ-变形细菌（Chromatiaceae）和较小比例的Chlorobi。在Alchichica和Atexcac湖中，保守的核心占总群落的40％（相对丰度），显示出最高的碱度和最显着的微生物。