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Microbiology Commons

Open Access. Powered by Scholars. Published by Universities.®

2005

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Karen Lloyd

Articles 1 - 2 of 2

Full-Text Articles in Microbiology

Methanogen Diversity Evidenced By Molecular Characterization Of Methyl Coenzyme M Reductase A (Mcra) Genes In Hydrothermal Sediments Of The Guaymas Basin, Ashita Dhillon, Mark Lever, Karen Lloyd, Daniel B. Albert, Mitchell L. Sogin, Andreas Teske Mar 2005

Methanogen Diversity Evidenced By Molecular Characterization Of Methyl Coenzyme M Reductase A (Mcra) Genes In Hydrothermal Sediments Of The Guaymas Basin, Ashita Dhillon, Mark Lever, Karen Lloyd, Daniel B. Albert, Mitchell L. Sogin, Andreas Teske

Karen Lloyd

The methanogenic community in hydrothermally active sediments of Guaymas Basin (Gulf of California, Mexico) was analyzed by PCR amplification, cloning, and sequencing of methyl coenzyme M reductase (mcrA) and 16S rRNA genes. Members of the Methanomicrobiales and Methanosarcinales dominated the mcrA and 16S rRNA clone libraries from the upper 15 cm of the sediments. Within the H2/CO2- and formate-utilizing family Methanomicrobiales, two mcrA and 16S rRNA lineages were closely affiliated with cultured species of the genera Methanoculleus and Methanocorpusculum. The most frequently recovered mcrA PCR amplicons within the Methanomicrobiales did not branch with any cultured genera. Within the nutritionally versatile …


Effects Of Dissolved Sulfide, Ph, And Temperature On Growth And Survival Of Marine Hyperthermophilic Archaea, Karen Lloyd, Virginia P. Edgcomb, Stephen J. Molyneaux, Simone Böer, Carl O. Wirsen, Michael S. Atkins, Andreas Teske Jan 2005

Effects Of Dissolved Sulfide, Ph, And Temperature On Growth And Survival Of Marine Hyperthermophilic Archaea, Karen Lloyd, Virginia P. Edgcomb, Stephen J. Molyneaux, Simone Böer, Carl O. Wirsen, Michael S. Atkins, Andreas Teske

Karen Lloyd

The ability of metabolically diverse hyperthermophilic archaea to withstand high temperatures, low pHs, high sulfide concentrations, and the absence of carbon and energy sources was investigated. Close relatives of our study organisms, Methanocaldococcus jannaschii, Archaeoglobus profundus, Thermococcus fumicolans, and Pyrococcus sp. strain GB-D, are commonly found in hydrothermal vent chimney walls and hot sediments and possibly deeper in the subsurface, where highly dynamic hydrothermal flow patterns and steep chemical and temperature gradients provide an ever-changing mosaic of microhabitats. These organisms (with the possible exception of Pyrococcus strain GB-D) tolerated greater extremes of low pH, high sulfide concentration, and high temperature …