Publications

4794

Abstract Me.tha.no.bre.vi.bac'ter. M.L. neut. n. methanum methane; L. masc. adj. brevis short; M.L. masc. n. bacter equivalent of Gr. neut. n. bakterion rod, staff; M.L. masc. n. Methanobrevibacter short methane (‐producing) rod. Oval rods or cocci to short rods , usually occurring in pairs or chains; about 0.5–0.7 µm in width and 0.8–1.4 µm in length. Rarely, filaments are formed. Nonsporing, Gram‐positive. Cell walls are composed of pseudomurein . Nonmotile. Strict anaerobes. Optimum temperature, 37–40°C; maximum, ~45°C; minimum, ~30°C. The mol % G + C of the DNA is : 27.5–31.6. Type species : Methanobrevibacter ruminantium (Smith and Hungate 1958) Balch and Wolfe 1981, 216 (Effective publication: Balch and Wolfe in Balch, Fox, Magrum, Woese and Wolfe, 1979, 284) ( Methanobacterium ruminantium Smith and Hungate 1958, 717). Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Methanobrevibacter is: correct name (last update, February 2025) * . LPSN classification: Archaea / Methanobacteriati / Methanobacteriota / Methanobacteria / Methanobacteriales / Methanobacteriaceae / Methanobrevibacter The genus Methanobrevibacter can also be recovered in the Genome Taxonomy Database (GTDB) as g__Methanobrevibacter (version v220) ** . GTDB classification: d__Archaea / p__Methanobacteriota / c__Methanobacteria / o__Methanobacteriales / f__Methanobacteriaceae / g__Methanobrevibacter * Meier‐Kolthoff et al. ( 2022 ). Nucleic Acids Res , 50 , D801 – D807 ; DOI: 10.1093/nar/gkab902 ** Parks et al. ( 2022 ). Nucleic Acids Res , 50 , D785 – D794 ; DOI: 10.1093/nar/gkab776

Phy.to.plas'ma. Gr. masc. n.phytosa plant; Gr. neut. n.plasmasomething formed or molded, a form.Tenericutes / Mollicutes / Acholeplasmatales / incertae Sedis ‐ Family II / “Candidatus Phytoplasma”Phytoplasmas (Sears and Kirkpatrick, 1994) are wall‐less, nutritionally fastidious, phytopathogenic prokaryotes 0.2–0.8 µm in diameter that morphologically resemble members of theMollicutes. Sequencing of nearly full‐length PCR‐amplified 16S rRNA genes (Gundersen et al., 1994; Namba et al., 1993; Seemüller et al., 1994), combined with earlier studies (Kuske and Kirkpatrick, 1992b; Lim and Sears, 1989), provided the first comprehensive phylogeny of the organisms and showed that they constitute a unique, monophyletic clade within theMollicutes. These organisms are most closely related to members of the genusAcholeplasmawithin theAnaeroplasmaclade as defined by Weisburg et al. (1989). Sustained culture in cell‐free media has not yet been demonstrated for any phytoplasma. Their genome sizes have been estimated to range from 530 to 1350 kb, and the G+C content of phytoplasma DNA is about 23–30 mol%. The presence of a characteristic oligonucleotide sequence in the 16S rRNA gene, CAA GAY BAT KAT GTK TAG CYG GDC T, and standard codon usage indicate that phytoplasmas represent a distinct taxon for which the name “CandidatusPhytoplasma” has been adopted by specialists in the molecular biology and pathogenicity of these and similar phytopathogenic organisms (IRPCM Phytoplasma/Spiroplasma Working Team – Phytoplasma Taxonomy Group, 2004). At present, the designation “Candidatus” must still be used for new types.