Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan, ROC.
Institute of Oceanography, National Taiwan University, Taipei, Taiwan, ROC.
Int J Syst Evol Microbiol. 2023 Nov;73(11). doi: 10.1099/ijsem.0.006164.
A novel mesophilic, hydrogenotrophic methanogen, strain CYW5, was isolated from a sediment sample of a piston core collected from submarine mud volcano MV5 located in the offshore area of southwestern Taiwan. Cells of strain CYW5 were irregular coccids, 0.5-1.0 µm in diameter and lysed easily by 0.01 % sodium dodecyl sulphate (SDS) treatment. Strain CYW5utilized formate or hydrogen plus carbon dioxide as catabolic substrates for methanogenesis. The optimal growth conditions were 37 °C, 0.043-0.085 M NaCl and pH 6.02-7.32. The genomic DNA G+C content calculated from the genome sequence of strain CYW5 was 56.2 mol%. The results of phylogenetic analysis of 16S rRNA gene sequences indicated that strain CYW5 represented a member of the family in the order , and was closely related to the members of the genus . The most closely related species was JR1 (94.9 % of 16S rRNA gene sequence identity). The average nucleotide identity and average amino acid identity values between strain CYW5 and members of the family were 74.7-78.5 % and 49.1-64.9%, respectively. Although many of the morphological and physiological characteristics of strain CYW5 and the species of the genus were similar, they were distinguishable by the differences in genomic G+C content and temperature, NaCl and pH ranges for growth. Based on these phenotypic, phylogenetic and genomic results, we propose that strain CYW5 represents a novel species, of a novel genus, named gen. nov., sp. nov. The type strain is CYW5 (=BCRC AR10048=DSM 100756=NBRC 111404).
一株新型中温、氢营养型产甲烷古菌，CYW5 菌株，从位于台湾西南近海海底泥火山 MV5 的岩芯沉积物样本中分离得到。CYW5 菌株的细胞呈不规则球菌，直径 0.5-1.0μm，易被 0.01%十二烷基硫酸钠（SDS）处理裂解。CYW5 菌株利用甲酸盐或氢气加二氧化碳作为产甲烷的分解代谢底物。其最佳生长条件为 37°C、0.043-0.085 M NaCl 和 pH6.02-7.32。根据 CYW5 菌株基因组序列计算的基因组 DNA G+C 含量为 56.2 mol%。16S rRNA 基因序列的系统发育分析结果表明，CYW5 菌株代表了目 科 中的一个成员，与属 的成员密切相关。最密切相关的物种是 JR1（16S rRNA 基因序列相似度为 94.9%）。与科内其他成员相比，CYW5 菌株与科内其他成员的平均核苷酸同一性和平均氨基酸同一性分别为 74.7-78.5%和 49.1-64.9%。尽管 CYW5 菌株和属 物种的许多形态和生理特征相似，但它们在基因组 G+C 含量以及生长的温度、NaCl 和 pH 范围方面存在差异，因此可以区分开来。基于这些表型、系统发育和基因组结果，我们建议 CYW5 菌株代表一个新属、新种，命名为 属，种名未知。其模式菌株为 CYW5（=BCRC AR10048=DSM 100756=NBRC 111404）。
