Atmospheric chemosynthesis is phylogenetically and geographically widespread and contributes significantly to carbon fixation throughout cold deserts

• DOI: 10.1038/s41396-022-01298-5
• Publication Date: 2022-08-06T13:02:57Z
• Authors: Angelique E Ray; Julian Zaugg; Nicole Benaud; Devan S Chelliah; Sean Bay; Hon Lun Wong; Pok Man Leung; Mukan Ji; Aleks Terauds; Kate Montgomery; Chris Greening; Don A Cowan; Weidong Kong; Timothy J Williams; Philip Hugenholtz; Belinda C Ferrari
• Keywords: Chemosynthesis; Extremophile; Cold seep

Cold desert soil microbiomes thrive despite severe moisture and nutrient limitations. In Eastern Antarctic soils, bacterial primary production is supported by trace gas oxidation the light-independent RuBisCO form IE. This study aims to determine if atmospheric chemosynthesis widespread within Antarctic, Arctic Tibetan cold deserts, identify breadth of chemosynthetic taxa further characterize genetic determinants this process. H2 was ubiquitous, far exceeding rates reported fulfill maintenance needs similarly structured edaphic microbiomes. Atmospheric occurred globally, contributing significantly (p < 0.05) carbon fixation in Antarctica high Arctic. Taxonomic functional analyses were performed upon 18 metagenomes, 230 dereplicated medium-to-high-quality derived metagenome-assembled genomes (MAGs) an additional 24,080 publicly available genomes. Hydrogenotrophic carboxydotrophic growth markers widespread. IE discovered co-occur alongside enzymes representative Chloroflexota, Firmicutes, Deinococcota Verrucomicrobiota We a novel group high-affinity [NiFe]-hydrogenases, 1m, through phylogenetics, gene structure analysis homology modeling, reveal substantial diversity (rbcL1E), 1h 1l [NiFe]-hydrogenase groups. conclude that globally-distributed phenomenon, extending throughout with significant implications for global cycle survival environmental reservoirs.