@article{mbs:/content/journal/ijsem/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.", title = "Methanocaldococcus bathoardescens sp. nov., a hyperthermophilic methanogen isolated from a volcanically active deep-sea hydrothermal vent", journal= "International Journal of Systematic and Evolutionary Microbiology", year = "2015", volume = "65", number = "Pt_4", pages = "1280-1283", doi = "https://doi.org/10.1099/ijs.0.000097", url = "https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.000097", publisher = "Microbiology Society", issn = "1466-5034", type = "Journal Article", abstract = "A hyperthermophilic methanogen, strain JH146T, was isolated from 26 °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 JH146T represents a novel species. For each analysis, strain JH146T was most similar to Methanocaldococcus sp. FS406-22, which can fix N2 and also comes from Marker 113 vent. However, strain JH146T differs from strain FS406-22 in that it cannot fix N2. The average nucleotide identity score for strain JH146T was 87 %, the genome-to-genome direct comparison score was 33–55 % and the species identification score was 93 %. For each analysis, strain JH146T was below the species delineation cut-off. Full-genome gene synteny analysis showed that strain JH146T and strain FS406-22 have 97 % genome synteny, but strain JH146T 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 JH146T is suggested to represent a novel species of the genus Methanocaldococcus for which the name Methanocaldococcus bathoardescens is proposed. The type strain is JH146T ( = DSM 27223T = KACC 18232T).", }