bioRxiv | 2021
Ecological relevance of abundant and rare taxa in a highly-diverse elastic hypersaline microbial mat, using a small-scale sampling
Abstract
We evaluated the microbial diversity and metabolomic signatures of a hypersaline elastic microbial mat from Cuatro Ciénegas Basin (CCB) in the Chihuahuan Desert of Coahuila, México. We collected ten samples within a small scale (1.5-meters transect) and found a high microbial diversity through NGS-based ITS and 16S rRNA gene sequencing. A very low number of taxa were abundant and shared between all sites, whereas the rare biosphere was more phylogenetically diverse (FPD index) and phylogenetically disperse (PSC index) than the abundant taxa for both analyzed libraries. In regard to potential biotic interactions (Pearson analysis), there were more positive correlations than negative. We also found a distinctive metabolomic signature for each sample and were able to tentatively annotate several classes of compounds with relevant biological properties. Together, these results reveal cohesive, diverse and fluctuating microbial communities, where abundant and rare taxa appear to have different ecological roles.