Diversity of an uncommon elastic hypersaline microbial mat along a small-scale transect

Abstract

We evaluated the microbial diversity and metabolome profile of an uncommon hypersaline elastic microbial mat from Cuatro Ciénegas Basin (CCB) in the Chihuahuan Desert of Coahuila, México. We collected ten samples on a small scale transect (1.5-m) and described its microbial diversity through NGS-based ITS and 16S rDNA gene sequencing. A very low number of taxa comprised a considerable proportion of the mat and were shared across all sampling points, whereas the rare biosphere was more phylogenetically diverse (Faith’s Phylogenetic Diversity (FPD) index) and phylogenetically disperse (using a null model distribution of Phylogenetic Species Clustering (nmdPSC)) than the abundant (high read count) taxa for both analyzed libraries. We also found a distinctive metabolome profile for each sample and were able to tentatively annotate several classes of compounds with relevant biological properties.

Metagenomic comparisons reveal a highly diverse and unique viral community in a seasonally fluctuating hypersaline microbial mat

“…One possible evidence of virus-host interactions in AD is the relatively high abundance of reads assigned to viruses infecting Archaea, which is consistent with the high abundance and diversity of Archaea reported in previous studies [9,10]. Also, the increase in Archaea abundance to 16 % since 2019 may be associated with an increase in virus abundance (Fig.…”

“…Despite its fluctuating and extreme nature, AD seem to harbour a seasonally stable microbial core community, with some degree of functionally redundant taxa [10] and a high abundance of alkaline and salt resistance genes [14]. AD is also very diverse in microbes, including more than 6000 ASV in ten samples obtained at a scale of 1.5 m [10]. This diversity includes a high abundance of halotolerant bacteria, as well as halophilic and methanogenic archaea [9,10].…”

“…AD is a seasonal fluctuating site, with the N:P ratio, pH and salinity ranging from 10 : 1, 9.5 and low hypersaline (5.3 %) during the wet season () to 78 : 1, 5.5 and high hypersaline (saturation) during the dry season (), respectively [9, 10]. Despite its fluctuating and extreme nature, AD seem to harbour a seasonally stable microbial core community, with some degree of functionally redundant taxa [10] and a high abundance of alkaline and salt resistance genes [14]. AD is also very diverse in microbes, including more than 6000 ASV in ten samples obtained at a scale of 1.5 m [10].…”

“…AD is also very diverse in microbes, including more than 6000 ASV in ten samples obtained at a scale of 1.5 m [10]. This diversity includes a high abundance of halotolerant bacteria, as well as halophilic and methanogenic archaea [9,10]. AD is particularly rich and diverse in archaea, which are rare in the rest of CCB [9,10].…”

“…This diversity includes a high abundance of halotolerant bacteria, as well as halophilic and methanogenic archaea [9,10]. AD is particularly rich and diverse in archaea, which are rare in the rest of CCB [9,10]. Hypersaline environments are characterized by higher salt concentrations than those of seawater (3-4 %) [15] and are usually classified according to their salinity levels; from low salinity (< 10 % NaCl), to intermediate salinity (10 %-20 % NaCl) and high salinity (> 20 % NaCl) [16].…”