%0 Journal Article %A Weng, Chieh-Yin %A Chen, Sheng-Chung %A Lai, Mei-Chin %A Wu, Sue-Yao %A Lin, Saulwood %A Yang, Tsanyao F. %A Chen, Po-Chun %T Methanoculleus taiwanensis sp. nov., a methanogen isolated from deep marine sediment at the deformation front area near Taiwan %D 2015 %J International Journal of Systematic and Evolutionary Microbiology, %V 65 %N Pt_3 %P 1044-1049 %@ 1466-5034 %R https://doi.org/10.1099/ijs.0.000062 %I Microbiology Society, %X A mesophilic, hydrogenotrophic methanogen, strain CYW4T, was isolated from deep-sea sediment obtained by the Ocean Researcher I cruiser, ORI-961, in 2011. The sediment was from the deformation front area offshore of south-western Taiwan. Here, seismic reflections indicated that methane hydrates were abundant. The methanogenic substrates utilized by strain CYW4T were formate and H2/CO2, but not acetate, secondary alcohols, methylamines, methanol and ethanol. Cells of strain CYW4T were non-motile, irregular cocci and 0.6–1.5 µm in diameter. The S-layer protein had an M r of 112 000. The optimum growth conditions were at 37 °C, pH 8.1 and 0.08 M NaCl. Growth of the strain was stimulated by acetate. The G+C content of the chromosomal DNA of strain CYW4T was 61 mol%. Phylogenetic analysis revealed that strain CYW4T was most closely related to Methanoculleus marisnigri JR1T (96.82 % 16S rRNA gene sequence similarity). Based on the morphological, phenotypic and phylogenetic characteristics presented here, it is evident that strain CYW4T represents a novel species of the genus Methanoculleus , and the name Methanoculleus taiwanensis sp. nov. is proposed. The type strain is CYW4T ( = BCRC AR10043T = NBRC 110782T). The optical density of cultures of strain CYW4T dropped abruptly upon entering the stationary growth phase. During this time numerous particles of approximately 50 nm in diameter were observed on and around the cells. This suggests that strain CYW4T harbours a lytic virus that is induced in the stationary phase, which is of interest because only a few lytic viruses have been reported in methanogens. %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.000062