Microbial Mats of the McMurdo Dry Valleys, Antarctica: Oases of Biological Activity in a Very Cold Desert

Cyanobacterial mats in the Antarctic Dry Valleys are photosynthetic microbial ecosystems living at the extreme of conditions on Earth with respect to temperature, light, water and nutrient availability. They are metabolically active for about 8 weeks during the austral summer when temperatures brief...

Full description

Bibliographic Details
Published in:Frontiers in Microbiology
Main Authors: Jill A. Sohm, Thomas D. Niederberger, Alexander E. Parker, Joƫlle Tirindelli, Troy Gunderson, Stephen Craig Cary, Douglas G. Capone, Edward J. Carpenter
Format: Article in Journal/Newspaper
Language:English
Published: Frontiers Media S.A. 2020
Subjects:
Online Access:https://doi.org/10.3389/fmicb.2020.537960
https://doaj.org/article/6f1be388f1b7421cbe50300be7fff658
Description
Summary:Cyanobacterial mats in the Antarctic Dry Valleys are photosynthetic microbial ecosystems living at the extreme of conditions on Earth with respect to temperature, light, water and nutrient availability. They are metabolically active for about 8 weeks during the austral summer when temperatures briefly rise above freezing and glacial and lake melt waters are available. There is much to learn about the biogeochemical impact of mats in these environments and the microbial communities associated with them. Our data demonstrate that these mats attain surprisingly high rates of carbon (CO2) and dinitrogen (N2) fixation when liquid water is available, in some cases comparable to rates in warmer temperate or tropical environments. C and N2 fixation in Dry Valley mats in turn substantially elevate dissolved organic C and inorganic N pools and thereby promote enhanced microbial secondary production. Moreover, the microbial community fingerprint of these mats is unique compared with the more ubiquitous dry soils that do not contain mats. Components of the heterotrophic microbiota may also contribute substantially to N inputs through N2 fixation.