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Project Progress

Cold Regions: Microbial Ecology and Biomarkers (dm)

This project investigates microbial ecology and the production of life in cold regions. Progress includes the documentation and description of microbial life in perennially ice covered lakes in McMurdo Dry Valleys of Antarctica. These lakes were found to have active and diverse microbial ecosystems The lakes are highly stratified in regard to supersaturation of gases (O2, NO2, H2S), contain strong salinity gradients, and a 20 degree range of temperatures from top to bottom. The ice cover reduces the flux of light by more than 98%. In spite of these harsh conditions, bacteria, lysogenic bacteria, and viruses are present in all of the samples and are similar in abundance to that found in open ocean water of more temperate conditions.

In a related study, water emerging from springs in glaciers in the Canadian Arctic have been identified as containing both biofilms and bacterial cells. Deposits of yellow and white minerals are formed on the surface as the water evaporates. These deposits include gypsum and sulfur. The water is no more than 1-2 degrees C and the microbes may be growing in the plumbing system of the glacier interior. Such occurrences in terrestrial glaciers may be mirrored on Mars during periods when the polar ice caps are melting or retreating.

In yet another facet of this project, we are studying psychrophilic microorganisms collected from the Fox permafrost tunnel in Alaska, piedmont glaciers and tidewater glaciers in Alaska, and the Vostok core in Antarctica. Samples include a variety of fungi, bacteria, and cyanobacteria, some of which have been cultured.