HR: 0800h
AN: P51D-0969    [Abstracts]
TI: Ambient Pressure Microbes Taken to Extreme: an Update on Their Survival and Growth
AU: * Sharma, A
EM: anurag_sharma @ rpi.edu
AF: Rensselaer Polytechnic Institute, Dept of Earth and Env. Sciences 110, 8th Street, Troy, NY 12180 United States
AB: What is the base of the biosphere? What are the various niches life as we know can persist? These are few of the questions that need to be addressed to constrain the extent of biological activity within the deep subsurface. Not unlike any other scientific inquiry, along with extensive field and theoretical studies, these geomicrobiological questions need an experiment-based evaluation that can help constrain the geochemical parameters relevant to life's survival. Recently, Sharma et al. (2002, Science) have taken a direct approach in constraining the microbial activity at extreme conditions by making observations within diamond anvil cells. Specific chemical component (formate) was used to constrain the metabolic activity of ambient pressure microbes at high pressures. This study opened up the possibility of life in radically extreme environments, often deficient of liquid water and showed that microbial life can find niches within the organic rich veins and inclusions, such as in (dense phase) ice. High resolution imaging within the diamond cell has provided a better insight into the state of the ambient pressure microbes. The author will present new results on microbial survival at high pressures that show high hydrostatic pressure affects some microbes differently such that they do perish, while others remain largely viable. By monitoring microbial growth upon decompression, these experiments show the viability of the microbes at high pressures and hence the feasibility of a deep biosphere.
UR: http://hyperbug.geo.rpi.edu/asharma/index.html
DE: 0463 Microbe/mineral interactions
DE: 3613 Subduction zone processes (1031, 3060, 8170, 8413)
DE: 3616 Hydrothermal systems (0450, 1034, 3017, 4832, 8135, 8424)
DE: 3694 Instruments and techniques
SC: Planetary Sciences [P]
MN: Fall Meeting 2005