9815512 PRISCU Three to twenty meter thick permanent ice covers on lakes in the McMurdo Dry Valleys, Antarctic contain viable microbial cells in association with sediment aggregates. These aggregates are now recognized as sites where physical, chemical and biological interactions promote microbial growth under extreme conditions inherent to the ice environment. This interdisciplinary research program will define specific processes which allow (1) the creation of liquid water (the essential element for life) in the permanent ice, (2) the survival and structuring of microbial populations subjected to freezing and thawing, (3) the production of substances which alter the physical attributes of the ice crystal habitat and (4) nutrient supply to the microbial populations which is essential for not only survival, but net microbial growth and biomass accumulation. The work will be on ice aggregates embedded within the permanent ice covers on the lakes in the Taylor Valley, which have been tentatively characterized in previous studies. Research on microbes in permanent ice provides information on the ecology of microbes in ice ecosystems and promises to have biotechnological implications. Furthermore, these studies will provide insights into the conditions, which support or have supported life beyond our own planet in association with water ice which is currently present within and beyond our own solar system.
