New taxonomy of methanogens based on the analysis of lipid component parts

由于已知的产甲烷菌80%是在1979年Balch等人发表基于rRNA寡核苷酸编目的产甲烷菌分类学之后分离的，因此，我们在新近发展的脂质组分分析的基础上，从属的层次上重新审视了产甲烷菌的分类学。产甲烷菌组之间的脂质组分的分布被发现是特定的类群在一个科或属的水平。甲烷微菌科和甲烷产甲烷菌科的产甲烷菌之间的脂质组分的差异很大，足以将这两个科重新分类为两个独立的目的。也就是说，应该提出一个新的命令Methanobenzinales。同样，应该提出，Methanocaldococcaceae是一个新的家庭的超嗜热甲烷球菌，Mco。Jannaschii和Mco。火。嗜热物种的属Methanosaeta被发现是不同的，从属的嗜温物种的脂质成分部分，这表明这两个物种应该属于不同的属。该方法已用于日本产甲烷菌的鉴定。

Because almost 80% of the methanogen species known to data were isolated after 1979 when Balch et al published methanogen taxonomy based on rRNA oligonucleotide cataloging method, the taxonomy of methanogens were reexaminned at order to genus levels on the basis of the lipid component parts analysis newly developed by us. The distribution of lipid component parts among methanogen groups was found to be specific to taxa at a family or genus level. The differences in the lipid components between methanogens of the families Methanosacinaceae and Methanomicrobiaceae were great enough to reclassify these two families into two separate orders. That is, a news order Methanosarcinales should be proposed. Similarly it should be proposed that Methanocaldococcaceae is a new family for the hyperthermophilic methanococci, Mco. Jannaschii and Mco. igneus. Thermophilic species of the genus Methanosaeta was found to be different in their lipid component parts from the mesophilic species of the genus, suggesting that both species should fall into separate genera. This method was applied to identification of methanogens isolated in Japan recently.