Abstract
On the basis of an extended investigation of morphological, biochemical and physiological properties and its phylogenetic affiliation it is proposed to place Methanomicrobium paynteri (Rivard et al. 1983, 24), validly published in 1984 (Rivard et al. 1984, 25) within a new genus, Methanolacinia gen. nov. as Methanolacinia paynteri comb. nov. Its cell envelope consists of a cytoplasmic membrane and a hexagonally arranged S-layer with a lattice constant of the geometrical subunits of 15.3nm, while the periodic structures on the cell envelope of Methanomicrobium mobile were not characterized. The S-layer contains a glycoprotein subunit with an apparent molecular weight of 155, 000. The polyamine pattern of Methanolacinia paynteri is comparable to that of Methanogenium species but differs significantly from that of Methanomicrobium mobile. Comparative lipid analyses of Methanomicrobium mobile, Methanogenium cariaci, Methanospirillum hungatei and Methanolacinia paynteri reveal marked differences. Furthermore, Methanolacinia paynteri grows not only on H2/CO2 as reported, but also on 2-propanol/CO2, 2-butanol/CO2 and cyclopentanol/CO2.
Together with the low SAB-value of 0.51, which Methanolacinia paynteri shares with Methanomicrobium mobile, these features corroborate the proposed reclassification.
