Methanothermus fervidus, sp. nov., a novel extremely thermophilic methanogen isolated from an Icelandic hot spring

Abstract

A rod-shaped extremely thermophilic methanogen is described, growing between 65 and 97 °C with an optimal temperature around 83 °C and a doubling time of 170 min. The GC-content of its DNA is 33 mol %. The isolated cell wall sacculus contains pseudomurein. The complex cell envelope exhibits two layers, each about 12 nm thick; the inner represents the pseudomurein sacculus and the outer a protein envelope. An enriched fraction of RNA polymerase does not react with antiserum against RNA polymerase from Methanobacterium thermoautotrophicum, indicating that the isolate belongs to a new family, the Methanothermaceae, within the order Methanobarteriales. The new organism is named Methanothermus fervidus.

Lipid sugar carriers at the extremes: The phosphodolichols Archaea use in N-glycosylation

“…Moreover, the enzyme thought to add the initial sugar to the lipid carrier in M. maripaludis was shown to be more active when presented with C 55,60 DolP rather than with longer C 85–105 DolP, as found in eukaryotes [54]. In contrast, older studies conducted on Methanothermus fervidus (optimal growth at 83°C in a 80% H 2 /20% CO 2 atmosphere [55]), where the S-layer glycoprotein is modified by an N-linked hexasaccharide, detected sugar-modified C 55 DolPP [56]. …”

Influence of Amino Acids on Growth and Cell Wall Composition of Methanobacteriales

“…Methanobacterium uliginosum (DSM 2956) is our own isolate. Methanobrecibacter arboriphilus (37 "C), Methanobacterium uliginosum (37 "C ; Konig 1984), Methanobacterium therrnoautotrophicum (64 "C) and Methanothermus.fercidus (84 "C; Stetter et al, 1981) were grown in serum bottles with H,/CO, (80 : 20; 300 kPa) at 100 r.p.m. or in a 10-litre fermenter (New Brunswick) sparged with H,/CO, (80:20) in medium 1 of Balch et af.…”

Isolation and characterization of Methanobacterium uliginosum sp. nov. from a marshy soil

“…These bacteria have in common a cell wall composed of pseudomurein (Konig, Kralik et al 1982). Only one extremely thermophilic species of the Methanothermaceae, Methanothermus fewidus, has been isolated so far (Stetter et al 1981 (Balch et al 1979 …”