https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_57-58/010025232.pdf

Production, oxidation, emission and consumption of methane by soils: A review

Soil microorganisms as controllers of atmospheric trace gases (H2, CO, CH4, OCS, N2O, and NO).

Most methanogenic archaea can reduce CO(2) with H(2) to methane, and it is generally assumed that the reactions and mechanisms of energy conservation that are involved are largely the same in all methanogens. However, this does not take into account the fact that methanogens with cytochromes have considerably higher growth yields and threshold concentrations for H(2) than methanogens without cytochromes. These and other differences can be explained by the proposal outlined in this Review that in methanogens with cytochromes, the first and last steps in methanogenesis from CO(2) are coupled chemiosmotically, whereas in methanogens without cytochromes, these steps are energetically coupled by a cytoplasmic enzyme complex that mediates flavin-based electron bifurcation.

Methanogenic archaea: ecologically relevant differences in energy conservation.

Real-time polymerase chain reaction (PCR) is a highly sensitive method that can be used for the detection and quantification of microbial populations without cultivating them in anaerobic processes and environmental samples. This work was conducted to design primer and probe sets for the detection of methanogens using a real-time PCR with the TaqMan system. Six group-specific methanogenic primer and probe sets were designed. These sets separately detect four orders (Methanococcales, Methanobacteriales, Methanomicrobiales, and Methanosarcinales) along with two families (Methanosarcinaceae and Methanosaetaceae) of the order Methanosarcinales. We also designed the universal primer and probe sets that specifically detect the 16S rDNA of prokaryotes and of the domain Bacteria and Archaea, and which are fully compatible with the TaqMan real-time PCR system. Target-group specificity of each primer and probe set was empirically verified by testing DNA isolated from 28 archaeal cultures and by analyzing potential false results. In general, each primer and probe set was very specific to the target group. The primer and probe sets designed in this study can be used to detect and quantify the order-level (family-level in the case of Methanosarcinales) methanogenic groups in anaerobic biological processes and various environments.

Group-Specific Primer and Probe Sets to Detect Methanogenic Communities Using Quantitative Real-Time Polymerase Chain Reaction

Max-Planck-Institut fur terrestrische Mikrobiologie, Karl-von-Frisch-Strase, D-35043 Marburg, and Laboratorium fur Mikrobiologie, Fachbereich Biologie, Philipps-Universitat, Karl-von-Frisch-Strase, D-35032 Marburg, Germany
In 1933, Stephenson & Stickland (1933a) published that they had isolated from river mud, by the single cell technique, a methanogenic organism capable of growth in an inorganic medium with formate as the sole carbon source.

Biochemistry of methanogenesis: a tribute to Marjory Stephenson:1998 Marjory Stephenson Prize Lecture

The production of methane is a ubiquitous, defining characteristic of methanogens. The production of methane or any other hydrocarbon as a major catabolic product is unique to this group of microbes, which share many other characteristics that are not common among other microbes. Phylogenetically, methanogens are Archaeobacteria (Woese et al., 1978), a group of microbes that are distinguished from true bacteria by a number of characteristics, including the possession of membrane lipids composed of isoprenoids ether-linked to glycerol or other carbohydrates (De Rosa and Gambacorta, 1988; Jones et al., 1987; Langworthy, 1985), a lack of peptidoglycan containing muramic acid (Kandier and Hippe, 1977), and distinctive ribosomal RNA sequences (Balch et al., 1979; Woese, 1987). This group also includes some extreme halophiles and some extremely thermophilic, sulfur-dependent microbes (Woese, 1987) and is phylogenetically distinct from eukaryotes and true bacteria (Figure 1.1).

Pierre Rouvière

Papers

Diversity and Taxonomy of Methanogens