Elevational Constraints on the Composition and Genomic Attributes of Microbial Communities in Antarctic Soils

• Published in: mSystems
• Main Authors: Nicholas B. Dragone, Jessica B. Henley, Hannah Holland-Moritz, Melisa Diaz, Ian D. Hogg, W. Berry Lyons, Diana H. Wall, Byron J. Adams, Noah Fierer
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Society for Microbiology 2022
• Subjects: Antarctica; microbial ecology; soil microbiology; soils; Microbiology; QR1-502; Antarctic; The Antarctic; Shackleton; Shackleton Glacier; Antarc*
• Online Access: https://doi.org/10.1128/msystems.01330-21; https://doaj.org/article/804d90c4d5c34fb4977c9953d35d5334

ABSTRACT The inland soils found on the Antarctic continent represent one of the more challenging environments for microbial life on Earth. Nevertheless, Antarctic soils harbor unique bacterial and archaeal (prokaryotic) communities able to cope with extremely cold and dry conditions. These communities are not homogeneous, and the taxonomic composition and functional capabilities (genomic attributes) of these communities across environmental gradients remain largely undetermined. We analyzed the prokaryotic communities in soil samples collected from across the Shackleton Glacier region of Antarctica by coupling quantitative PCR, marker gene amplicon sequencing, and shotgun metagenomic sequencing. We found that elevation was the dominant factor explaining differences in the structures of the soil prokaryotic communities, with the drier and saltier soils found at higher elevations harboring less diverse communities and unique assemblages of cooccurring taxa. The higher-elevation soil communities also had lower maximum potential growth rates (as inferred from metagenome-based estimates of codon usage bias) and an overrepresentation of genes associated with trace gas metabolism. Together, these results highlight the utility of assessing community shifts across pronounced environmental gradients to improve our understanding of the microbial diversity found in Antarctic soils and the strategies used by soil microbes to persist at the limits of habitability. IMPORTANCE Antarctic soils represent an ideal system to study how environmental properties shape the taxonomic and functional diversity of microbial communities given the relatively low diversity of Antarctic soil microbial communities and the pronounced environmental gradients that occur across soils located in reasonable proximity to one another. Moreover, the challenging environmental conditions typical of most Antarctic soils present an opportunity to investigate the traits that allow soil microbes to persist in some of the most inhospitable habitats on Earth. ...