Publications

4983

Apart from sharing the basic cellular features of otherBacteria, the cyanobacteria possess unique and diagnostic characteristics that will be briefly described here, but less extensively than in the 1989 edition ofBergey's Manual of Systematic Bacteriology. The cell wall in cyanobacteria is of a Gram‐negative type. Cell division in most unicellular and colonial cyanobacteria and some filamentous forms is by binary fission. Regarding cell exterior and motility, fimbriae (or pili) occur abundantly with diverse patterns in many cyanobacteria. Although not all thylakoids in cyanobacteria appear to be invaginations of the cytoplasmic membrane, there are orderly “attachment points” or “thylakoid centers” associated with the periphery of the cytoplasm or the cytoplasmic membrane. In the cytoplasm of cyanobacteria there are many other components and “inclusions”, most of which can be visualized readily using various preparative techniques for transmission electron microscopy. They include glycogen granules, cyanophycin granules, carboxysomes (polyhedral bodies), polyphosphate (volutin) granules, and gas vacuoles. Heterocysts, akinetes, and hormogonia are some of the specialized cells and differentiation in Cyanobacteria. The chief physiological/biochemical characteristic of cyanobacteria, distinguishing them from all other procaryotes, is the dual photosystem that allows the use of H2O as photoreductant with the consequent liberation of O2. Two courses for the delimitation of genera have been followed by cyanobacterial specialists: (a) to retain “small” genera or (b) to gather many species into fewer genera.Cyanobacteria / General Characteristics of the Cyanobacteria

Abstract A.my.co.la.top'sis. N.L. fem. n. Amycolata genus belonging to the order Actinomycetales ; Gr. fem. n. opsis aspect, appearance; N.L. fem. n. Amycolatopsis that which appears similar to Amycolata . Aerobic to facultatively anaerobic , Gram‐stain‐positive , non‐acid‐fast , nonmotile , catalase‐positive actinomycetes that form branching substrate hyphae which fragment into squarish and rod‐shaped elements . When formed , aerial hyphae may be sterile or differentiate into chains of smooth‐walled , squarish to ellipsoidal spore‐like structures . Chemo‐organotrophic to facultatively autotrophic. Grows on a broad range of organic and synthetic media. Mesophilic or thermophilic. Whole‐organism hydrolysates are rich in meso ‐2 , 6‐diaminopimelic acid , arabinose , and galactose . The peptidoglycan is of the A1γ type. Muramic acid moieties are N ‐acetylated. The diagnostic phospholipid is phosphatidylethanolamine ( with or without phosphatidylmethylethanolamine ) or phosphatidylmethylethanolamine with variable occurrence of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositol mannosides; contains complex mixtures of saturated and branched chain fatty acids . Does not contain mycolic acids. The phylogenetic position of Amycolatopsis , as determined by 16S rRNA gene sequence analysis, is in the family Pseudonocardiaceae . Common in arid soils but has also been isolated from activated sludge, equine placentas, and from clinical and plant material. DNA G + C content ( mol %): 66–75 ( T m ; HPLC). Type species : Amycolatopsis orientalis (Pittenger and Brigham 1956) Lechevalier, Prauser, Labeda and Ruan 1986, 35 VP . Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Amycolatopsis is: correct name (last update, February 2025) * . LPSN classification: Bacteria / Bacillati / Actinomycetota / Actinomycetes / Pseudonocardiales / Pseudonocardiaceae / Amycolatopsis The genus Amycolatopsis can also be recovered in the Genome Taxonomy Database (GTDB) as g__Amycolatopsis (version v220) ** . GTDB classification: d__Bacteria / p__Actinomycetota / c__Actinomycetes / o__Mycobacteriales / f__Pseudonocardiaceae / g__Amycolatopsis * 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

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

Abstract Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Candidatus Paracaedibacter is: preferred name (not correct name) (last update, February 2025) * . LPSN classification: Bacteria / Pseudomonadati / Pseudomonadota / Alphaproteobacteria / Holosporales / Candidatus Paracaedibacteraceae / Candidatus Paracaedibacter Candidatus Paracaedibacter could not be recovered in GTDB ** . * 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

Abstract Cla.vi.chla.my'di.a. L. n. clava a knotty branch, rough stick, cudgel, club; N.L. fem. n. Chlamydia taxonomic name of a bacterial genus; N.L. fem. n. Clavichlamydia a club Chlamydia (the morphology of the bacteria includes the characteristic head‐and‐tail cells that have been described earlier from salmonid fish suffering from epitheliocystis). Pleomorphic or elongated , nonmotile , obligate intracellular bacteria , up to 2 μ m in length . Cells show a developmental cycle with morphologically distinct stages and thrive inside a host vacuole . Organisms were found within gill lesions of fish and are differentiated from all other chlamydiae by the morphology of the proposed elementary bodies , which show a characteristic head‐and‐tail form (Figure 1). Members have not yet been obtained in cell culture. Type species : “ Candidatus Clavichlamydia salmonicola ” corrig. Karlsen, Nylund, Watanabe, Helvik, Nylund and Plarre 2008. Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Candidatus Clavichlamydia is: preferred name (not correct name) (last update, February 2025) * . LPSN classification: Bacteria / Pseudomonadati / Chlamydiota / Chlamydiia / Chlamydiales / Chlamydiaceae / Candidatus Clavichlamydia The genus Candidatus Clavichlamydia can also be recovered in the Genome Taxonomy Database (GTDB) as g__Clavichlamydia (version v220) ** . GTDB classification: d__Bacteria / p__Chlamydiota / c__Chlamydiia / o__Chlamydiales / f__Chlamydiaceae / g__Clavichlamydia * 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.

Abstract Xi.phi.ne.ma.to.bac'ter. Gr. neut. n. Xiphinema, ‐atos the genus name of the host organism; N.L. masc. n. bacter the equivalent of Gr. neut. n. baktron a rod; N.L. masc. n. Xiphinematobacter the rod‐shaped microbe associated with Xiphinema . Full‐grown cells are rod‐shaped with rounded ends, 0.7–1.0 × 2.1–3.2 μm ; however, cells in the J 1 (first juvenile) stage of nematode development have a wrinkled, pleomorphic shape. The longer entities usually consist of a mother cell from which a daughter cell is budding, giving rise to serial pairs typical of this bacterial genus. In thin sections cells have two or three membranes consisting of, from inside to outside, a cytoplasmic membrane, an electron‐dense outer membrane, and, in many individuals, a vacuolar membrane which is probably derived from the host cell membrane and which often shows discontinuities. No peptidoglycan layer is evident ; however, a periplasmic hexagonally arrayed monolayer of 10 nm protein units is sometimes present. Gram‐stain‐negative, nonmotile, and nonsporulating. DNA is often condensed at cell poles . Bacteria live as obligate cytoplasmic symbionts with maternal transmission in nematodes of the Xiphinema americanum group ( Nematoda, Longidoridae ), in which they are presumed to induce thelytokous ( mother‐to‐daughter ) parthenogenesis . DNA G + C content ( mol %): not determined. Type species : “ Candidatus Xiphinematobacter brevicolli ” Vandekerckhove, Willems, Gillis and Coomans 2000, 2203. Taxonomic and Nomenclature Notes According to the List of Prokaryotic names with Standing in Nomenclature (LPSN), the taxonomic status of the genus Candidatus Xiphinematobacter is: preferred name (not correct name) (last update, February 2025) * . LPSN classification: Bacteria / Pseudomonadati / Verrucomicrobiota / Terrimicrobiia / Terrimicrobiales / Chthoniobacteraceae / Candidatus Xiphinematobacter Candidatus Xiphinematobacter could not be recovered in GTDB ** . * 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