HR: 10:20h
AN: B12B-01 INVITED     [Abstracts]
TI: Carbon-Isotope Fractionations of Autotrophic Bacteria: Relevance to Primary Production and Microbial Evolution in Hot Springs and Hydrothermal Vents
AU: * Zhang, C L
EM: zhang@srel.edu
AF: Savannah River Ecology Laboratory, Savannah River Site Drawer E, Bldg 737A, Aiken, SC 29802 United States
AU: Romanek, C S
EM: romanek@srel.edu
AF: Savannah River Ecology Laboratory, Savannah River Site Drawer E, Bldg 737A, Aiken, SC 29802 United States
AU: Mills, G
EM: mills@srel.edu
AF: Savannah River Ecology Laboratory, Savannah River Site Drawer E, Bldg 737A, Aiken, SC 29802 United States
AB: Terrestrial hot springs and marine hydrothermal vents are often dominated by autotrophic microorganisms. Species of the Bacteria Domain in these environments are known to use different pathways for CO$_{2}$ fixation. These may include the Calvin cycle, the Acetyl CoA pathway, the reverse TCA cycle, and the 3-HP pathway. Each cycle or pathway may be characterized by distinct patterns of carbon isotope fractionation. This presentation will summarize isotope fractionation patterns associated with known autotrophic bacteria and to use these patterns for interpreting natural isotopic variations. Examples will include hot springs from the Yellowstone National Park and Nevada desert, USA and Kamchatka, Russia, and hydrothermal vents from the East Pacific Rise. An attempt will be made to discuss isotopic variations within a particular pathway in the context of species evolution through horizontal gene transfer.
DE: 4806 Carbon cycling
DE: 4840 Microbiology
DE: 4870 Stable isotopes
DE: 4803 Bacteria
DE: 1615 Biogeochemical processes (4805)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting