Kazuhide Yamasato

Phylogenetic diversity of the genus Cytophaga revealed by 16S rRNA sequencing and menaquinone analysis

To clarify the intra- and intergeneric relationships of the genus Cytophaga, 16S rRNA sequences and respiratory isoprenoid quinones were determined for the type strains of the 21 validly published species and one isolate in the genus Cytophaga. The sequence analysis revealed extreme heterogeneity of this genus, which diverged into nine distinct lines of descent. Each lineage of Cytophaga was characterized by possessing either menaquinone-6 (MK-6) or MK-7. The MK-6-possessing species were located in the two lineages that were remote from MK-7 species. One of the MK-6 lineages was composed only of terrestrial species and the other only of marine species. Flavobacterium aquatile, the type species of the genus Flavobacterium, was located in the MK-6 terrestrial lineage. The terrestrial Cytophaga species with MK-6 should be transferred to the genus Flavobacterium. The marine facultative anaerobes with MK-7 were located in the bacteroides branch, and possessed signature sequences with features intermediate between the bacteroides and the flavobacteria subdivisions. Cytophaga hutchinsonii, the type species of the genus Cytophaga, had a close relationship only with Cytophaga aurantiaca. The genus Cytophaga should be restricted to these two cellulose-degrading species. The genus Cytophaga is so heterogeneous that it should be divided into several genera and higher taxa in accordance with the phylogenetic relationships.

Taxonomic Study of Bacteria Isolated from Plants: Proposal of Sphingomonas rosa sp. nov., Sphingomonas pruni sp. nov., Sphingomonas asaccharolytica sp. nov., and Sphingomonas mali sp. nov.

The taxonomic positions of 10 strains of 3-ketolactose-forming bacteria which were isolated from the roots of plants (Rosa sp., Psychotria nairobiensis, Ardisia crispa, Prunus persica, and apple trees) were investigated. The DNA base compositions of these strains ranged from 64.0 to 65.7 mol%, the isoprenoid quinone of each strain was ubiquinone 10, 3-hydroxy fatty acids were lacking in the cellular fatty acids of these organisms, and all of the strains contained a sphingolipid with the long-chain base dihydrosphingosin. These are characteristics of the genus Sphingomonas. On the basis of morphological, physiological, and chemotaxonomic characteristics, together with DNA-DNA hybridization and 16S ribosomal DNA sequence comparison data, we propose the following four new species of the genus Sphingomonas: Sphingomonas rosa (type strain, IFO 15208) for the strains isolated from rose plants and formerly named [Agrobacterium rhizogenes]; Sphingomonas pruni (type strain, IFO 15498) for the strains isolated from Prunus persica; and Sphingomonas asaccharolytica (type strain, IFO 15499) and Sphingomonas mali (type strain, IFO 15500) for the strains isolated from apple trees. Two strains which were isolated from Psychotria nairobiensis and formerly named [Chromobacterium lividum] were identified as Sphingomonas yanoikuyae strains.

Alicyclobacillus herbarius sp. nov., a novel bacterium containing omega-cycloheptane fatty acids, isolated from herbal tea.

A thermo-acidophilic gram-positive bacterium, strain CP-1T, which grows aerobically at 35-65 degrees C (optimum 55-60 degrees C) and at pH 3.5-6.0 (optimum pH 4.5-5.0), was isolated from a herbal tea made from the dried flowers of hibiscus. Phylogenetic analysis of the 16S rRNA gene sequences showed that this bacterium was clearly distinguishable from previously described species of the genera Alicyclobacillus and Sulfobacillus. Strain CP-1T had unique omega-cycloheptane fatty acids as the major membrane lipid component, a characteristic which is peculiar to Alicyclobacillus cycloheptanicus. However, phenotypic and chemotaxonomic characteristics of strain CP-1T were different from those of the type strain of A. cycloheptanicus. DNA-DNA hybridization between the type strains of Alicyclobacillus species and Sulfobacillus disulfidooxidans was <20%, indicating that strain CP-1T represents a distinct species. On the basis of these results, the name Alicyclobacillus herbarius is proposed for this organism. The type strain is strain CP-1T (= DSM 13609T = IAM 14883T = NRIC 0477T).

Isoprenoid quinone composition of some marine Alteromonas, Marinomonas, Deleya, Pseudomonas and Shewanella species

The isoprenoid quinone composition of 51 Gram-negative, aerobic, marine bacteria representing the genera Alteromonas, Marinomonas, Deleya, Pseudomonas and Shewanella was examined using high-performance liquid chromatography. Alteromonas and Marinomonas strains contained ubiquinone with eight isoprene units as their most abundant component, whilst ubiquinones with nine isoprene units predominated in Deleya and marine Pseudomonas strains. Members of the genus Shewanella contained both ubiquinones and menaquinones. The presence of two types of isoprenoid quinones in Shewanella is thought to be unique amongst Gram-negative, aerobic bacteria. In addition, methylmenaquinones were also found in Shewanella putrefaciens strains. The results demonstrate that the analysis of isoprenoid quinones offers a rapid and effective method of differentiating between some marine bacteria.

Zymobacter palmae gen. nov., sp. nov., a new ethanol-fermenting peritrichous bacterium isolated from palm sap

Zymobacter palmae gen. nov., sp. nov. was proposed for a new ethanol-fermenting bacterium that was isolated from palm sap in Okinawa Prefecture, Japan. The bacterium is gram-negative, facultatively anaerobic, catalase-positive, oxidase-negative, nonspore-forming and peritrichously flagellated. It requires nicotinic acid for growth. It ferments hexoses, α-linked di- and tri-saccarides, and sugar alcohols (fructose, galactose, glucose, mannose, maltose, melibiose, saccharose, raffinose, mannitol and sorbitol). Fifteen percent of maltose in broth medium is effectively fermented, whereas glucose with a concentration higher than 10% delayed growth initiation and decreased growth rates. Maltose is fermented to produce ethanol and CO2 with a trace amount of acids. Approximately 2 mol of ethanol are produced from 1 mol moiety of hexose of maltose. The organism possesses ubiquinone-9. The G+C content of the DNA is 55.8+-0.4 mol%. Major cellular fatty acids were palmitic and oleic acids and cyclopropanic acid of C19:0. Characteristic hydroxylated acid was 3-hydroxy dodecanoic acid. The bacterium is distinct from other ethanol-fermenting bacteria belonging to the genera Zymomonas Kluyver and van Niel 1936 and Saccharobacter Yaping et al. 1990 with respect to chemotaxonomic and other phenotypic characters to warrant to compose a new genus and a new species. The type strain is strain T109 (= IAM 14233).

Alteromonas atlantica sp. nov. and Alteromonas carrageenovora sp. nov., bacteria that decompose algal polysaccharides

We studied seven strains of aerobic, marine, polarly flagellated bacteria which decompose alginate, agar, and carrageenan. The major respiratory quinone of these strains was ubiquinone-8. The G+C content of their DNA was 39.5 to 41.7 mol%. “Pseudomonas atlantica” IAM 12927 and the conspecific five isolates were concluded to constitute a single species distinguished from the other nonpigmented Alteromonas species by DNA-DNA hybridization (homology values of more than 82%) and phenotypic similarity (similarity coefficients, based on assimilation of 145 carbon compounds, were 79 to 96%). “Pseudomonas carrageenovora” IAM 12662, the sole extant strain, was distinct from “P. atlantica” and other Alteromonas species in DNA-DNA hybridization and phenotypic features. Taxonomic affinity to Alteromonas espejiana was indicated by DNA-DNA hybridization with “P. atlantica” IAM 12927 and the five conspecific isolates (39 to 55%) and with “P. carrageenovora” IAM 12662 (43 to 45%). Phenotypically, higher similarity values (79 to 89%) for assimilation of 145 carbon compounds were shared between A. espejiana IAM 12927T and the six conspecific strains, including “P. atlantica” IAM 12927. Alteromonas atlantica sp. nov. (type strain, IAM 12927, =ATCC 19262, =NCIMB 301) and Alteromonas carrageenovora (type strain, IAM 12662, =IFO 12985, =ATCC 43555, =NCIMB 302) are proposed for “P. atlantica” IAM 12927 and the conspecific five isolates and “P. carrageenovora” IAM 12662, respectively. A set of phenotypic features which differentiate the two Alteromonas species is described.

Propionibacterium cyclohexanicum sp. nov., a New Acid-Tolerant ω-Cyclohexyl Fatty Acid-Containing Propionibacterium Isolated from Spoiled Orange Juice

A non-spore-forming, coryneform bacterium, strain TA-12T, was isolated from spoiled off-flavor orange juice. Growth of this organism occurs at pH 3.2 to 7.5, and optimum growth occurs at pH values between 5.5 and 6.5. This organism produces lactic acid, propionic acid, and acetic acid from glucose. It is catalase negative. The cells are heat resistant and can withstand a temperature of 90 degrees C for 10 min. The DNA G + C content is 66.8 mol%. This strain has as MK-9(H4) respiratory quinone system and contains meso-diaminopimelic acid in its cell wall, and omega-cyclohexyl undecanoic acid is the major cellular fatty acid. The results of a phylogenetic analysis of the 168 rRNA gene of this organism indicated that its highest level of homology is its level of homology with the representative of the classical propionibacteria, Propionibacterium freudenreichii (97.1%). Strain TA-12T is phenotypically similar to P. freudenreichii, but it produces a large amount of lactic acid and has a distinct fatty acid composition, acid tolerance, and heat resistance, which differentiate it from P. freudenreichii and other propionic acid-producing bacteria. On the basis of these findings we propose the name Propionibacterium cyclohexanicum sp. nov. for this organism. The type strain is TA-12 (= IAM 14535 = NRIC 0247).

Is intracytoplasmic membrane structure a generic criterion? It does not coincide with phylogenetic interrelationships among phototrophic purple nonsulfur bacteria

The 16S rRNA or rRNA gene sequences of the type strains of 5 species of Rhodobacter, Rhodopseudomonas blastica and Paracoccus denitrificans were determined. The sequence analysis revealed that Rhodobacter species, whose intracytoplasmic membrane systems were characteristically vesicular, composed a sole cluster. Rhodopseudomonas blastica, whose intracytoplasmic membrane system was lamellar, was included in the cluster of Rhodobacter. The phylogenetic co-clustering of these bacteria conformed to their possessing of the identical types of carotenoids. Paracoccus denitrificans, which is nonphototrophic, is a right member of the Rhodobacter cluster. Rhodobacter species, Rhodopseudomonas blastica and Paracoccus denitrificans are apart from the other phototrophic bacteria and have the common deletions of 21 bases at the positions 1258 to 1278 (Escherichia coli numbering system). It was demonstrated that the morphological character “intracyto-plasmic membrane structure”, that has been regarded as a generic criterion does not reflect the phylogeny in the phototrophic bacteria. The transfer of Rhodopseudomonas blastica to the genus Rhodobacter is proposed.

Emendation of the Genus Cytophaga and Transfer of Cytophaga agarovorans and Cytophaga salmonicolor to Marinilabilia gen. nov.: Phylogenetic Analysis of the Flavobacterium - Cytophaga Complex

A 16S rRNA sequence analysis revealed that the genera Cytophaga, Flavobacterium, and Flexibacter are all polyphyletic and should be redefined and reorganized. Cytophaga hutchinsonii, the type species of the genus Cytophaga, belongs to a lineage that also contains Cytophaga aurantiaca. The genus Cytophaga is emended so that it contains only these two species, which decompose distinctly crystalline cellulose. Cytophaga salmonicolor and Cytophaga agarovorans form a lineage which is intermediate between other aerobic species and anaerobic bacteroides. Phenotypically, these organisms are characterized by being facultative anaerobes, inhabiting marine environments, and containing menaquinone-7 and spermidine. We propose that C. salmonicolor and C. agarovorans should be transferred to the genus Marinilabilia gen. nov. as Marinilabilia salmonicolor comb. nov. and Marinilabilia agarovorans comb. nov., respectively.

Endozoicomonas numazuensis sp. nov., a gammaproteobacterium isolated from marine sponges, and emended description of the genus Endozoicomonas Kurahashi and Yokota 2007.

Two non-motile, rod-shaped gammaproteobacteria were isolated from marine sponges collected from the coast of Japan at Numazu. The isolates were oxidase- and catalase-positive facultative anaerobes that fermented carbohydrates. They required sodium ions for growth and were slightly halophilic, growing in the presence of 1.0-5.0 % (w/v) NaCl (optimum of 2.0 % NaCl). Under aerobic conditions, the major isoprenoid quinones were ubiquinone-9 and menaquinone-9 and the minor quinones were ubiquinone-8 and menaquinone-8. The major cellular fatty acids were C(18 : 1)ω7c, C(16 : 1)ω7c and C(16 : 0) and the hydroxy acids were C(10 : 0) 3-OH and C(12 : 0) 3-OH. The DNA G+C content was 48.3-48.7 mol%. Phylogenetic analysis of 16S rRNA gene sequences placed the isolates within the radiation of the genus Endozoicomonas in a broad clade of uncultured clones recovered from various marine invertebrates. The isolates exhibited 96.5-96.9 % 16S rRNA gene sequence similarity with Endozoicomonas elysicola MKT110(T) and Endozoicomonas montiporae CL-33(T), with which the isolates formed a monophyletic cluster with 100 % bootstrap support. The phenotypic features (carbohydrate fermentation, quinone system and some major cellular fatty acids) differed from those of members of the genus Endozoicomonas, which are aerobic, produce little or no menaquinone under aerobic conditions and possess different amounts of C(14 : 0) and C(18 : 1)ω7c. Although some phenotypic differences were identified, the isolates should be assigned to the genus Endozoicomonas on the basis of congruity of phylogeny and should be classified as representatives of a novel species, for which the name Endozoicomonas numazuensis sp. nov. is proposed. The type strain is HC50(T) ( = NBRC 108893(T)  = DSM 25634(T)). An emended description of the genus Endozoicomonas is presented.