@article {1728, title = {Complete genome sequence of the hyperthermophilic methanogen Methanocaldococcus bathoardescens JH146(T) isolated from the basalt subseafloor.}, journal = {Mar Genomics}, volume = {24 Pt 3}, year = {2015}, month = {2015 Dec}, pages = {229-30}, abstract = {

Methanocaldococcus bathoardescens JH146(T) is a hyperthermophilic and obligate hydrogenotrophic methanogen isolated from low-temperature (26 {\textdegree}C) hydrothermal vent fluid at Axial Seamount in the northeastern Pacific Ocean. It is most closely related to the N2-fixing methanogen Methanocaldococcus sp. FS406-22; however, they differ in that JH146 cannot fix N2 or reductively assimilate nitrate. In this study, we present the complete genome sequence of strain JH146(T) (1,607,556 bp) with its 1635 protein coding genes, and 41 RNA genes. Our analysis focuses on its methane production via the acetyl-CoA pathway and its deleted gene clusters related to nitrogen assimilation. This study extends our understanding of methanogenesis at high temperatures and the impact of these organisms on the biogeochemistry of subseafloor hydrothermal environments and the deep sea.

}, issn = {1876-7478}, doi = {10.1016/j.margen.2015.06.002}, author = {Kim, You-Tae and Jung, Jong-Hyun and Stewart, Lucy C and Kwon, Soon-Wo and Holden, James F and Park, Cheon-Seok} } @article {1743, title = {Methanocaldococcus bathoardescens sp. nov., a hyperthermophilic methanogen isolated from a volcanically active deep-sea hydrothermal vent.}, journal = {Int J Syst Evol Microbiol}, volume = {65}, year = {2015}, month = {2015 Apr}, pages = {1280-3}, abstract = {

A hyperthermophilic methanogen, strain JH146(T), was isolated from 26 {\textdegree}C hydrothermal vent fluid emanating from a crack in basaltic rock at Marker 113 vent, Axial Seamount in the northeastern Pacific Ocean. It was identified as an obligate anaerobe that uses only H2 and CO2 for growth. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain is more than 97\% similar to other species of the genus Methanocaldococcus . Therefore, overall genome relatedness index analyses were performed to establish that strain JH146(T) represents a novel species. For each analysis, strain JH146(T) was most similar to Methanocaldococcus sp. FS406-22, which can fix N2 and also comes from Marker 113 vent. However, strain JH146(T) differs from strain FS406-22 in that it cannot fix N2. The average nucleotide identity score for strain JH146(T) was 87\%, the genome-to-genome direct comparison score was 33-55\% and the species identification score was 93\%. For each analysis, strain JH146(T) was below the species delineation cut-off. Full-genome gene synteny analysis showed that strain JH146(T) and strain FS406-22 have 97\% genome synteny, but strain JH146(T) was missing the operons necessary for N2 fixation and assimilatory nitrate reduction that are present in strain FS406-22. Based on its whole genome sequence, strain JH146(T) is suggested to represent a novel species of the genus Methanocaldococcus for which the name Methanocaldococcus bathoardescens is proposed. The type strain is JH146(T) ( = DSM 27223(T) = KACC 18232(T)).

}, keywords = {DNA, Bacterial, Hydrothermal Vents, Methanocaldococcus, Molecular Sequence Data, Pacific Ocean, Phylogeny, RNA, Ribosomal, 16S, Seawater, Sequence Analysis, DNA}, issn = {1466-5034}, doi = {10.1099/ijs.0.000097}, author = {Stewart, Lucy C and Jung, Jong-Hyun and Kim, You-Tae and Kwon, Soon-Wo and Park, Cheon-Seok and Holden, James F} } @article {1200, title = {Complete genome sequence of hyperthermophilic archaeon Thermococcus sp. ES1.}, journal = {J Biotechnol}, volume = {174C}, year = {2014}, month = {2014 Jan 25}, pages = {14-15}, abstract = {

Thermococcus sp. strain ES1 is an anaerobic, hyperthermophilic archaeon from a hydrothermal vent that catabolizes sugars and peptides and produces H2S from S{\textdegree}, H2, acetate and CO2 as its primary metabolites. We present the complete genome sequence of this strain (1,957,742bp) with a focus on its substrate utilization and metabolite production capabilities. The sequence will contribute to the development of heterotrophic archaea for bioenergy production and biogeochemical modeling in hydrothermal environments.

}, issn = {1873-4863}, doi = {10.1016/j.jbiotec.2014.01.022}, author = {Jung, Jong-Hyun and Kim, You-Tae and Jeon, Eun-Jung and Seo, Dong-Ho and Hensley, Sarah A and Holden, James F and Lee, Ju-Hoon and Park, Cheon-Seok} }