DNA sequence analysis of the human gut revealed the presence a seventh order of methanogens referred to as Methanomassiliicoccales. Methanomassiliicoccus luminyensis is the only member of this order that grows in pure culture. Here, we show that the organism has a doubling time of 1.8 d with methanol + H₂ and a growth yield of 2.4 g dry weight/mol CH₄. M. luminyensis also uses methylamines + H₂ (monomethylamine, dimethylamine, and trimethylamine) with doubling times of 2.1–2.3 d. Similar cell yields were obtained with equimolar concentrations of methanol and methylamines with respect to their methyl group contents. The transcript levels of genes encoding proteins involved in substrate utilization indicated increased amounts of mRNA from the mtaBC2 gene cluster in methanol-grown cells. When methylamines were used as substrates, mRNA of the mtb/mtt operon and of the mtmBC1 cluster were found in high abundance. The transcript level of mtaC2 was almost identical in methanol- and methylamine-grown cells, indicating that genes for methanol utilization were constitutively expressed in high amounts. The same observation was made with resting cells where methanol always yielded the highest CH₄ production rate independently from the growth substrate. Hence, M. luminyensis is adapted to habitats that provide methanol + H₂ as substrates.

中文翻译：

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发光甲烷球菌的生长特性及甲基转移酶编码基因的表达。


对人类肠道的 DNA 序列分析揭示了第七目产甲烷菌的存在，称为 Methanomassiliicoccales。 Methanomasiliicoccus luminyensis是该目中唯一在纯培养物中生长的成员。在这里，我们表明该生物体在甲醇 + H ₂下的倍增时间为 1.8 d，生长产量为 2.4 g 干重/mol CH ₄ 。 M. luminyensis还使用甲胺 + H ₂ （一甲胺、二甲胺和三甲胺），倍增时间为 2.1–2.3 d。使用等摩尔浓度的甲醇和甲胺（就其甲基含量而言）获得相似的细胞产量。编码参与底物利用的蛋白质的基因的转录水平表明，在甲醇生长的细胞中，来自mtaBC2基因簇的 mRNA 量增加。当使用甲胺作为底物时， mtb/mtt操纵子和mtmBC1簇的 mRNA 被发现具有高丰度。 mtaC2的转录水平在甲醇和甲胺生长的细胞中几乎相同，表明甲醇利用基因以高量组成型表达。对静息细胞进行了相同的观察，其中甲醇总是产生最高的CH ₄生产率，与生长底物无关。因此， M.luminyensis适应提供甲醇+H ₂作为底物的生境。