@article{mbs:/content/journal/ijsem/10.1099/ijs.0.63691-0, author = "Tsubota, Jun and Eshinimaev, Bulat Ts. and Khmelenina, Valentina N. and Trotsenko, Yuri A.", title = "Methylothermus thermalis gen. nov., sp. nov., a novel moderately thermophilic obligate methanotroph from a hot spring in Japan", journal= "International Journal of Systematic and Evolutionary Microbiology", year = "2005", volume = "55", number = "5", pages = "1877-1884", doi = "https://doi.org/10.1099/ijs.0.63691-0", url = "https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.63691-0", publisher = "Microbiology Society", issn = "1466-5034", type = "Journal Article", keywords = "PLFA, phospholipid fatty acid", keywords = "RuMP, ribulose monophosphate", keywords = "pMMO and sMMO, particulate and soluble methane monooxygenase, respectively", keywords = "ICM, intracytoplasmic membrane", abstract = "A novel moderately thermophilic methanotroph, strain MYHTT, was isolated from a hot spring in Japan. The isolate grew on methane or methanol at 37–67 °C, and optimally at 57–59 °C. It was found to be a Gram-negative aerobe, with colourless colonies of non-motile coccoid cells, possessing type I intracytoplasmic membranes and regularly arranged surface layers of linear (p2) symmetry. Strain MYHTT expressed only the particulate methane monooxygenase and employed the ribulose monophosphate pathway for formaldehyde assimilation. It is a neutrophilic and halotolerant organism capable of growth at pH 6·5–7·5 (optimum pH 6·8) and in up to 3 % NaCl (optimum 0·5–1 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequence analysis indicated that strain MYHTT is most closely related to the thermophilic undescribed methanotroph ‘Methylothermus’ HB (91 % identity) and the novel halophilic methanotroph Methylohalobius crimeensis 10KiT (90 % identity). Comparative sequence analysis of particulate methane monooxygenase (pmoA) genes also confirmed the clustering of strain MYHTT with ‘Methylothermus’ HB and Methylohalobius crimeensis 10KiT (98 and 92 % derived amino acid sequence identity, respectively). The DNA G+C content was 62·5 mol%. The major cellular fatty acids were C16 : 0 (37·2 %) and C18 : 1 ω9c (35·2 %) and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major ubiquinone was Q-8. On the basis of comparative phenotypic and genotypic characteristics, a new genus and species, Methylothermus thermalis gen. nov., sp. nov., is proposed, with MYHTT as the type strain (=VKM B-2345T=IPOD FERM P-19714T).", }