Nearing the cold-arid limits of microbial life in permafrost of an upper dry valley, Antarctica.
Some of the coldest and driest permafrost soils on Earth are located in the high-elevation McMurdo Dry Valleys (MDVs) of Antarctica, but little is known about the permafrost microbial communities other than that microorganisms are present in these valleys. Here, we describe the microbiology and habitable conditions of highly unique dry and ice-cemented permafrost in University Valley, one of the coldest and driest regions in the MDVs (1700 m above sea level; mean temperature -23 °C; no degree days above freezing), where the ice in permafrost originates from vapour deposition rather than liquid water. We found that culturable and total microbial biomass in University Valley was extremely low, and microbial activity under ambient conditions was undetectable. Our results contrast with reports from the lower-elevation Dry Valleys and Arctic permafrost soils where active microbial populations are found, suggesting that the combination of severe cold, aridity, oligotrophy of University Valley permafrost soils severely limit microbial activity and survival.
Department of Natural Resource Sciences, McGill University, Macdonald Campus, Ste-Anne-de-Bellevue, Quebec, Canada.
Jacqueline
J
Goordial
NASA Ames Research Center, Moffett Field, CA, USA.
Alfonso
A
Davila
Department of Geography, University of Ottawa, Ottawa, Ontario, Canada.
Denis
D
Lacelle
Department of Geography, McGill University, Montreal, Quebec, Canada.
Wayne
W
Pollard
NASA Ames Research Center, Moffett Field, CA, USA.
Margarita M
MM
Marinova
National Research Council Canada, Montreal, Quebec, Canada.
Charles W
CW
Greer
Biology Department, The Johns Hopkins University, Baltimore, MD, USA.
Jocelyn
J
DiRuggiero
NASA Ames Research Center, Moffett Field, CA, USA.
Christopher P
CP
McKay
Department of Natural Resource Sciences, McGill University, Macdonald Campus, Ste-Anne-de-Bellevue, Quebec, Canada.
Lyle G
LG
Whyte
D000864:Antarctic Regions; D001110:Arctic Regions; D003080:Cold Temperature; D003890:Desiccation; D017753:Ecosystem; D005843:Geography; D065946:Permafrost / Q000382:microbiology*; D012988:Soil Microbiology