The potential for microbial life in the highest elevation (>6000 m.a.s.l.) mineral soils of the Atacama region"

R.C. LYNCH; A.J. KING, ; P. SOWELL3, ; MARIÁ E. FARIAS; S.K. SCHMIDT

JGR-Biogeosciences

America Geophysical Union (AGU)

Año: 2012 vol. 01 p. 111111111 - 111111111

0148�0227

Here we present the first microbiological and biogeochemical study of the mineral soils from above 6000 meters above sea level (m.a.s.l.) on some the highest volcanoes in the Atacama region of Argentina and Chile. These soils experience some of the harshest environmental conditions on Earth including daily temperature fluctuations across the freezing point (with an amplitude of up to 70°C) and intense solar radiation. Soil carbon and water levels are among the lowest yet measured for a terrestrial ecosystem and enzyme activity was near or below detection limits for all microbial enzymes measured. The soil microbial communities were among the simplest yet studied in a terrestrial environment and contained novel Bacteria and Fungi and only one Archaeal phylotype. No photosynthetic organisms were detected and several of the dominant bacterial phylotypes are related to organisms involved in carbon monoxide oxidation on other volcanoes. Focused studies of the gene responsible for carbon monoxide oxidation, carbon monoxide dehydrogenase (CODH), revealed a diversity of novel CODH genes. Overall our results indicate that a unique microbial community, sustained by diffuse atmospheric and volcanic gases, is barely functioning on these volcanoes, which represent the highest terrestrial ecosystems yet studied.