Stromatolites are organo-sedimentary structures found principally in seas and saline lakes that contain sheets of sediments and minerals formed by layers of microbial communities, which trap sediments and induce the precipitation of minerals.

A living stromatolite from the alkaline Laguna Interna in the Salar de Atacama was collected and one of the fragments was deposited in an experimental aquarium for 18 months. We used Illumina sequencing of PCR-amplified V4 regions of 16S rRNA genes from total extracted DNA to identify the microbial populations. The chemical structure was studied using X-Ray Diffraction (XRD) and bench chemical methods. We found that members belonging to the Proteobacteria, Planctomycetes, Chloroflexi and Bacteroidetes phyla dominated the bacterial communities of the living and aquarium cultured samples. The potential metabolic functionality of the prokaryotic community reveals that sulfur, nitrogen, methane and carbon fixation metabolism functions are present in the samples. This study is the first to provide new insights into the prokaryotic community composition from this unusual aquatic desert site. Further studies will be helpful to obtain a better understanding of the biotic and abiotic mechanisms residing in stromatolites from Laguna Interna, as well as to have better knowledge about the formation of these biosignatures.

基质岩是一种有机沉积结构，主要存在于海洋和盐湖中，其中包含由微生物群落层形成的沉积物和矿物质薄片，这些沉积物和矿物质会诱捕沉积物并促使矿物沉淀。

收集了来自阿塔卡马萨拉尔（Salar de Atacama）碱性Laguna Interna的活层岩，并将其中一个碎片沉积在实验水族馆中18个月。我们使用Illumina测序从总提取DNA中扩增16S rRNA基因的PCR扩增V4区，以鉴定微生物种群。使用X射线衍射（XRD）和台式化学方法研究了化学结构。我们发现成员属于变形杆菌，扁平菌，Chloroflex i和拟杆菌属在生活和水族箱养殖样品的细菌群落中，门菌占主导地位。原核生物群落的潜在代谢功能表明样品中存在硫，氮，甲烷和碳固定代谢功能。这项研究是第一个为这个不寻常的水生沙漠遗址的原核生物群落组成提供新见解的研究。进一步的研究将有助于更好地了解拉古纳国际天体的叠层石中存在的生物和非生物机制，并有助于更好地了解这些生物特征的形成。