Weng Chieh-Yin, Chen Sheng-Chung, Lai Mei-Chin, Wu Sue-Yao, Lin Saulwood, Yang Tsanyao F, Chen Po-Chun
Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.
Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan.
Int J Syst Evol Microbiol. 2015 Mar;65(Pt 3):1044-1049. doi: 10.1099/ijs.0.000062. Epub 2015 Jan 9.
A mesophilic, hydrogenotrophic methanogen, strain CYW4(T), 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 CYW4(T) were formate and H2/CO2, but not acetate, secondary alcohols, methylamines, methanol and ethanol. Cells of strain CYW4(T) were non-motile, irregular cocci and 0.6-1.5 µm in diameter. The S-layer protein had an Mr 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 CYW4(T) was 61 mol%. Phylogenetic analysis revealed that strain CYW4(T) was most closely related to Methanoculleus marisnigri JR1(T) (96.82 % 16S rRNA gene sequence similarity). Based on the morphological, phenotypic and phylogenetic characteristics presented here, it is evident that strain CYW4(T) represents a novel species of the genus Methanoculleus, and the name Methanoculleus taiwanensis sp. nov. is proposed. The type strain is CYW4(T) ( = BCRC AR10043(T) = NBRC 110782(T)). The optical density of cultures of strain CYW4(T) 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 CYW4(T) 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.
2011年，从“海洋研究员一号”科考船ORI - 961采集的深海沉积物中分离出一株嗜温、以氢为营养源的产甲烷菌CYW4(T)。该沉积物来自台湾西南部近海的变形前沿区域。在此，地震反射表明甲烷水合物含量丰富。CYW4(T)菌株利用的产甲烷底物是甲酸盐和H₂/CO₂，而非乙酸盐、仲醇、甲胺、甲醇和乙醇。CYW4(T)菌株的细胞无运动性，呈不规则球菌状，直径为0.6 - 1.5 µm。S层蛋白的分子量为112 000。最佳生长条件为37℃、pH 8.1和0.08 M NaCl。乙酸盐可刺激该菌株生长。CYW4(T)菌株染色体DNA的G + C含量为61 mol%。系统发育分析表明，CYW4(T)菌株与黑海产甲烷菌JR1(T)关系最为密切（16S rRNA基因序列相似性为96.82%）。基于此处呈现的形态、表型和系统发育特征，显然CYW4(T)菌株代表了产甲烷菌属的一个新物种，因此提出新物种名称台湾产甲烷菌（Methanoculleus taiwanensis sp. nov.）。模式菌株为CYW4(T)（= BCRC AR10043(T) = NBRC 110782(T)）。CYW4(T)菌株培养物进入稳定生长期后光密度急剧下降。在此期间，在细胞表面及周围观察到许多直径约50 nm的颗粒。这表明CYW4(T)菌株含有一种在稳定期被诱导的裂解性病毒，这很有趣，因为在产甲烷菌中仅报道过少数裂解性病毒。
