Buford Price
University of California at Berkeley
and
Lawrence Berkeley National Laboratory
Abstract:
Our studies in the 3050-m-deep Greenland ice core show that micrometer-size microorganisms can live for millions of years in ice, even in the absence of air. Three of our findings are of particular interest to physicists and chemists: 1. Iron-reducing bacteria attached to clay grains near the bottom of the ice sheet extract energy by reducing ferric to ferrous ions throughout each grain, by a mechanism akin to D.C. electrical conductivity in mica. 2. Methanogens (methane-generating archaea) at several depths in the ice extract energy by reducing carbon dioxide to methane, which is detected in the ice at levels far in excess of that from the atmosphere. 3. I developed a method to measure metabolic rates of microbes imprisoned in ice. Those data allow me to specify where methanogens would be found if they are responsible for the methane recently discovered in the Mars atmosphere.