A shared core microbiome in soda lakes separated by large distances

Abstract

words)In alkaline soda lakes, high concentrations of dissolved carbonates establish an environment favouring productive phototrophic microbial mat communities. Here we show how different species of microbial phototrophs and autotrophs contribute to this exceptional productivity.Four years of amplicon and shotgun DNA sequencing data from microbial mats from four different lakes indicated the presence of over 2,000 different species of Bacteria and Eukaryotes.Metagenome-assembled-genomes were obtained for a core microbiome of <100 abundant bacteria, which was shared among lakes and accounted for half of the extracted DNA throughout the four year sampling period. Most of the associated species were related to similar microbes previously detected in sediments of Central Asian alkaline soda lakes,showing that common selection principles drive community assembly from a globally distributed reservoir of alkaliphile biodiversity. Dispersal events between the two distant lake systems were shown to be extremely rare, with dispersal rates a function of abundance in microbial mats, but not sediments. Detection of more than 7,000 expressed proteins showed how phototrophic populations allocated resources to specific processes and occupied complementary niches. Carbon fixation only proceeded by the Calvin-Benson-Bassham cycle, detected in Cyanobacteria, Alphaproteobacteria, and, suprisingly, Gemmatomonadetes. Our study not only provides new fundamental insight into soda lake ecology, but also provides a template, guiding future efforts to engineer robust and productive biotechnology for carbon dioxide conversion.

Ecology and biogeochemistry of the microbial underworld in two sister soda lakes

“…DNA (0.5-2 ng/uL) from Last Chance core #1 (Samples: LC1 -11 to -21) was sent to the Centre for Health Genomics and Informatics in the Cumming School of Medicine (University of Calgary) for the metagenomic library preparation and sequencing with a NextSeq 500 System (Illumina Inc., San Diego, CA, USA). Assembly and binning of the metagenomes followed the same procedure asDong et al, (2020) [64] andZorz et al, (2019) [16]. In brief, quality control of the raw reads was conducted using BBDuk from the BBTools package, which involved the removal of primers, adapters, and low-quality reads.…”