Page 101 - University of Pretoria Research Review 2017

Foreword
Introductory Messages
DEVELOPMENT AND CHANGE
PEOPLE AND CONTEXTS
Microbial Ecology and Biodiversity
Antarctic terrestrial microbial ecology
Don Cowan, Centre for Microbial Ecology and Genomics
The McMurdo Dry Valleys of South Victoria Land, Antarctica, represent one of the most extreme environments on Earth. Summer temperatures might rise a few degrees above 0°C for a few months during the 24-hour daylight period, but water is always scarce.
HEALTH AND WELL-BEING
PLANET AND SUSTAINABILITY
Awards
Lead Researchers
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Through the long winter months, during three of which the sun never rises, soil temperatures can plummet to -60°C. It is perhaps surprising that anything can survive these conditions, but two decades of research by Professor Don Cowan and members of his team from the Centre for Microbial Ecology and Genomics, with his international collaborators, have demonstrated that a wide diversity of soil microorganisms thrive under these extreme conditions.
The most active and complex terrestrial soil microbial communities exist in protected ‘niche’ habitats,
either inside or underneath transparent rocks. These endolithic and hypolithic communities represent biodiversity, biomass and functional ‘hotspots’ in otherwise low-biomass environments. These are the ‘tropical rainforests’ of the Antarctic Dry Valleys.
Professor Cowan’s Antarctic terrestrial microbial ecology studies are principally funded through the National Research Foundation’s SANAP programme. This new research project represents another step forward in the ongoing investigations of extreme microbiology: this time focusing on adaptation and community structural and functional resilience. The latter is currently at
the forefront of the minds of the world’s ecologists, since climate change patterns have already resulted
in significant warming trends across much of coastal and maritime Antarctica. The way in which sensitive, specialised and unique Antarctic biological communities may respond to these climate changes is currently unknown and is a cause for concern among the Antarctic conservation community.
Under the auspices of his new Antarctic microbiology project, Professor Cowan has collected a new set
of environmental samples from the Antarctic Dry Valleys. These samples will be the basis for a series
of experiments, based on modern Next Generation sequencing of total environmental DNA (broadly termed metagenomics), and aimed at investigating functional responses, capacity and resilience in soil microbial communities.
Don Cowan