Microbial ecology and biogeochemistry of continental Antarctic soils

• Published in: Frontiers in Microbiology
• Main Authors: Cowan, Don A., Makhalanyane, Thulani P., Dennis, Paul G., Hopkins, David W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Research Foundation 2014
• Subjects: Antarctica; Microbial ecology; Soil; Hypoliths; Nitrogen; Carbon; Adaptation; Threats; Impacts; Antarctic; New Zealand; Antarc*; Antarctica New Zealand; British Antarctic Survey; permafrost
• Online Access: http://hdl.handle.net/2263/43517; https://doi.org/10.3389/fmicb.2014.00154

The Antarctica Dry Valleys are regarded as the coldest hyperarid desert system on Earth. While a wide variety of environmental stressors including very low minimum temperatures, frequent freeze-thaw cycles and low water availability impose severe limitations to life, suitable niches for abundant microbial colonization exist. Antarctic desert soils contain much higher levels of microbial diversity than previously thought. Edaphic niches, including cryptic and refuge habitats, microbial mats and permafrost soils all harbor microbial communities which drive key biogeochemical cycling processes. For example, lithobionts (hypoliths and endoliths) possess a genetic capacity for nitrogen and carbon cycling, polymer degradation, and other system processes. Nitrogen fixation rates of hypoliths, as assessed through acetylene reduction assays, suggest that these communities are a significant input source for nitrogen into these oligotrophic soils. Here we review aspects of microbial diversity in Antarctic soils with an emphasis on functionality and capacity. We assess current knowledge regarding adaptations to Antarctic soil environments and highlight the current threats to Antarctic desert soil communities. University of Pretoria Genomics Research Institute, The South African National Research Foundation (SANAP program), Antarctica New Zealand, the University of Waikato NZTABS program, the UK Natural Environment Research Council (Antarctic Funding Initiative) and the British Antarctic Survey. http://www.frontiersin.org/Microbiology hb2015