HR: 0800h
AN: T31A-0481    [Abstracts]
TI: Bacterial and Archaeal Diversity From the Eastern Lau Spreading Center
AU: * Reysenbach, A
EM: reysenbacha@pdx.edu
AF: Portland State University, 1719 SW 10th Ave Biology Department, Portland, OR 97201
AU: Banta, A
EM: bantaa@pdx.edu
AF: Portland State University, 1719 SW 10th Ave Biology Department, Portland, OR 97201
AU: Kelly, S
EM: smkelly@pdx.edu
AF: Portland State University, 1719 SW 10th Ave Biology Department, Portland, OR 97201
AU: Kirshstein, J
EM: jkirshte@usgs.gov
AF: USGS, 12201 Sunrise Valley Drive, Reston, VA 20192
AU: Voytek, M
EM: mavoytek@usgs.gov
AF: USGS, 12201 Sunrise Valley Drive, Reston, VA 20192
AB: Due to the diversity of venting styles, geological settings and variations in fluid geochemistry, the Valu Fa Ridge and Eastern Lau Spreading Center (ELSC) provide a unique opportunity to explore the effects geological and geochemical variables on patterns of microbial phylogenetic and metabolic diversity. High temperature sulfides, diffuse flow fluids and microbial mats were collected from six active vent fields on the Valu Fa Ridge and Eastern Lau Spreading Center during the R/V Melville cruise TUIM05MV. All samples were subsampled for molecular and microbial culturing purposes. The archaeal and bacterial 16S rRNA genes were amplified by PCR from a selection of samples. Additionally, the presence of Aquificales and an unidentified lineage, the DHVE archaeal group, was explored using PCR primers specific for these groups. A selection of DNAs were also screened for functional genes that are diagnostic for certain pathways, viz, aclB (reductive TCA cycle), mcrA (methanogenesis), nirS and nirK (nitrite reduction), amoA (ammonia oxidation). Culturing of thermophiles, both acidophiles and neutrophiles, was initiated. Over 20 hydrogen oxidizing (hydrogen and oxygen) or nitrate reducing (hydrogen and nitrate) chemolithoautotrophs were isolated as colonies and grow at 70 degrees C. All are related to Persephonella hydrogenophila, with the exception of 2 cultures that perhaps represent new species of Hydrogenivirga and Aquifex. Preliminary analysis of patterns of Aquificales diversity using both culturing and molecular approaches suggest that the distributions of this group alone are very different from that observed at other hydrothermal sites such as along the East Pacific Rise or Central Indian Ridge. As yet, the most commonly isolated Aquificales, P. marina, has not been detected in enrichment cultures from ELSC, and the diversity of Aquificales-related sequences is much greater than detected from sites along the EPR. It is therefore also likely, that patterns of archaeal and bacterial diversity will reflect the geochemical differences within ELSC and between EPR and ELSC.
DE: 0410 Biodiversity
DE: 0463 Microbe/mineral interactions
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
DE: 4832 Hydrothermal systems (0450, 1034, 3017, 3616, 8135, 8424)
SC: Tectonophysics [T]
MN: Fall Meeting 2005