HR: 1340h
AN: B13A-1047    [Abstracts]
TI: Microbial Populations in Extreme Environments: Investigations and Characterizations of the Microbiology and Geochemistry of Galapagos Island Fumaroles
AU: * Mayhew, L E
EM: mayh6704@uidaho.edu
AF: University of Idaho Department of Geological Sciences, PO Box 443022, Moscow, ID 83844
AU: Childers, S E
EM: childers@uidaho.edu
AF: University of Idaho Department of Geological Sciences, PO Box 443022, Moscow, ID 83844
AU: Geist, D
EM: dgeist@uidaho.edu
AF: University of Idaho Department of Geological Sciences, PO Box 443022, Moscow, ID 83844
AB: The extreme physiochemical conditions, insularity, and wide range in ages of fumaroles of the Galapagos Islands provide an excellent opportunity to explore for novel microorganisms and to study life in extreme environments. This is the first study that measures microbial diversity of Galapagos fumaroles. Forty-seven samples were collected from six distinct fumarole fields on Sierra Negra and Alcedo volcanoes. Vulcan Chico, on Sierra Negra, was activated during the last eruption in 1979. Two of the other fumarole fields on Sierra Negra are associated with a long-lived fault system on the caldera floor and are therefore likely to be significantly older. The fault-associated fumaroles have widespread alteration haloes (up to 100 m in diameter) and thick deposits of native sulfur. The most vigorous of the fumarole fields on Alcedo activated in late 1993 to early 1994. The second fumarole field on Alcedo is associated with a recently extinct geyser and the third is located on a rhyolite vent. A diversity of colors was observed in the substrates at all of the fumarole fields and some may be the result of microbial activity. Collection sites were chosen on the basis of temperature and the variations in the substrate in order to obtain samples from a variety of environments. Temperatures at sample sites range from 25.0 to 178.5° C, and pH from 0 to 6. The material collected varies between sites and includes crystalline sulfur deposits, clay, sandy and rocky soils, and microbial mats. Substrate material is characterized by powder x-ray diffractometry and scanning electron microscopy and gases collected from five of the fumarole fields are being analyzed to test for chemical controls on the microbial populations. Genomic DNA is being extracted from all of the samples. Primers for Bacteria and Archaea are used for PCR amplification of the 16S rRNA gene. To date, 22 of 37 processed samples have amplifiable DNA. Microbial diversity of samples possessing amplifiable DNA is being assessed by denaturing gradient gel electrophoresis (DGGE). These results may reveal the presence of novel organisms and will provide insights into how vent age, insularity, temperature, pH, and geochemistry influence the microbial populations in extreme environments in the Galapagos Islands.
DE: 0410 Biodiversity
DE: 0448 Geomicrobiology
DE: 0456 Life in extreme environments
SC: Biogeosciences [B]
MN: Fall Meeting 2005