- Volume 56, Issue 7, 2006

A novel anaerobic, moderately thermophilic bacterium, strain Cas60314T, was isolated from hot oil-well production water obtained from an oil reservoir in the North Sea. The cells were Gram-negative, motile, straight rods. The salinity and pH growth optima were 2.0–3.0 % NaCl and 6.5–7.0, respectively. The optimum temperature was 58 °C. Strain Cas60314T had a fermentative type of metabolism and utilized proteinous substrates, some single amino acids and a limited number of organic acids, but not sugars, fatty acids or alcohols. Cystine and elemental sulfur were reduced to sulfide. The G+C content of the DNA was 46.6 mol%. On the basis of phenotypic and phylogenetic features, it is proposed that this isolate represents a novel genus and species with the name Thermovirga lienii gen. nov., sp. nov. within the family Syntrophomonadaceae. The proposed type strain is strain Cas60314T (=DSM 17291T=ATTC BAA-1197T).

Desulfovibrio vulgaris subsp. oxamicus (type strain, DSM 1925T) was found to use nitrate as a terminal electron acceptor, the latter being reduced to ammonium. Phylogenetic studies indicated that strain DSM 1925T was distantly related to the type strain of Desulfovibrio vulgaris (95.4 % similarity of the small-subunit rRNA gene) and had as its closest phylogenetic relatives two other nitrate- and sulfate-reducing bacteria, namely Desulfovibrio termitidis (99.4 % similarity) and Desulfovibrio longreachensis (98.4 % similarity). Additional experiments were conducted to characterize better strain DSM 1925T. This strain incompletely oxidized lactate and ethanol to acetate. It also oxidized butanol, pyruvate and citrate, but not glucose, fructose, acetate, propionate, butyrate, methanol, glycerol or peptone. The optimum temperature for growth was 37 °C (range 16–50 °C) and the optimum NaCl concentration for growth was 0.1 % (range 0–5 %). Because of significant genotypic and phenotypic differences from Desulfovibrio termitidis and Desulfovibrio longreachensis, reclassification of Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov., is proposed. The type strain is strain Monticello 2T (=DSM 1925T=NCIMB 9442T=ATCC 33405T).

A Gram-negative, motile, denitrifying bacterium (strain AcBE2-1T) was isolated from activated sludge of a municipal wastewater treatment plant using 17β-oestradiol (E2) as sole source of carbon and energy. Cells were curved rods, 0.4–0.8×0.8–2.0 μm in size, non-fermentative, non-spore-forming, oxidase-positive and catalase-negative. E2 was oxidized completely to carbon dioxide and water by reduction of nitrate to a mixture of dinitrogen monoxide and dinitrogen, with the intermediate accumulation of nitrite. Electron recoveries were between 90 and 100 %, taking assimilated E2 into account. With nitrate as the electron acceptor, the bacterium also grew on fatty acids (C2 to C6), isobutyrate, crotonate, dl-lactate, pyruvate, fumarate and succinate. Phylogenetic analysis of its 16S rRNA gene sequence revealed that strain AcBE2-1T represents a separate line of descent within the family Rhodocyclaceae (Betaproteobacteria). The closest relatives are the cholesterol-degrading, denitrifying bacteria Sterolibacterium denitrificans DSM 13999T and strain 72Chol (=DSM 12783), with <93.9 % sequence similarity. The G+C content of the DNA was 61.4 mol%. Detection of a quinone system with ubiquinone Q-8 as the predominant compound and a fatty acid profile that included high concentrations of C16 : 1 ω7c/iso-C15 : 0 2-OH and C16 : 0, in addition to C18 : 1 ω7c and small amounts of C8 : 0 3-OH, supported the results of the phylogenetic analysis. On the basis of 16S rRNA gene sequence data in combination with chemotaxonomic and physiological data, strain AcBE2-1T (=DSM 16959T=JCM 12830T) is placed in a new genus Denitratisoma gen. nov. as the type strain of the type species Denitratisoma oestradiolicum gen. nov., sp. nov.

A Gram-negative, microaerophilic helical rod, isolated from the gastric mucosa of a dog and designated strain JKM4T, was subjected to a polyphasic taxonomic study. The tightly coiled organism, measuring 10–18 μm long and up to 1 μm wide, was motile by means of multiple sheathed flagella located at both ends of the cell and by a periplasmic fibril running along the external side of the helix. Strain JKM4T grew preferably on biphasic culture plates or on very moist agar. Coccoid forms predominated in cultures older than 4 days as well as in growth obtained on dry agar plates. The strain grew at 30 and 37 °C, but not at 25 or 42 °C and exhibited urease, oxidase and catalase activities. On the basis of 16S rRNA gene sequence analysis, the novel isolate was identified as a member of the genus Helicobacter and showed > 97 % similarity to Helicobacter felis, Helicobacter bizzozeronii and Helicobacter salomonis, three species previously isolated from the canine gastric mucosa. Protein profiling of strain JKM4T using SDS-PAGE revealed a pattern different from those of other Helicobacter species of mammalian gastric origin and from Helicobacter canis. Additionally, the urease gene sequence of strain JKM4T was different from those of urease genes of H. felis, H. bizzozeronii, H. salomonis and ‘Candidatus Helicobacter heilmannii’. It is thus proposed that strain JKM4T (=LMG 23188T) represents a novel species within this genus, Helicobacter cynogastricus sp. nov.

Six strains representing three novel species were isolated from deep-sea sediment in Suruga Bay, Japan, at a depth of 2406–2409 m. On the basis of 16S rRNA gene sequence analysis, the isolated strains, c931T, c941T, d943, c952, d954 and c959T, are closely affiliated with members of the genus Shewanella. The hybridization values for DNA–DNA relatedness between these strains and Shewanella reference strains were significantly lower than that which is accepted as the phylogenetic definition of a species. On the basis of their distinct taxonomic characteristics, the isolated strains represent three novel Shewanella species, for which the names Shewanella kaireitica sp. nov. (three strains, type strain c931T=JCM 11836T=DSM 17170T), Shewanella abyssi sp. nov. (two strains, type strain c941T=JCM 13041T=DSM 17171T) and Shewanella surugensis sp. nov. (type strain c959T=JCM 11835T=DSM 17177T) are proposed.

A Gram-negative, non-spore-forming, rod-shaped, motile bacterium, strain Ko06T, was isolated from soil from a ginseng field in South Korea and was characterized in order to determine its taxonomic position. 16S rRNA gene sequence analysis revealed that strain Ko06T belongs to the Gammaproteobacteria, and the highest levels of sequence similarity were with Thermomonas brevis LMG 21746T (98.4 %), Thermomonas fusca LMG 21737T (97.7 %), Thermomonas haemolytica A50-7-3T (96.5 %) and Thermomonas hydrothermalis SGM-6T (95.8 %). Chemotaxonomic data revealed that strain Ko06T possesses ubiquinone Q-8 and that the predominant fatty acids are C15 : 0 iso, C11 : 0 iso and C11 : 0 iso 3-OH, all of which corroborated assignment of the strain to the genus Thermomonas. The results of DNA–DNA hybridization and physiological and biochemical tests clearly demonstrated that strain Ko06T represents a distinct species. On the basis of these data, strain Ko06T (=KCTC 12540T=NBRC 101155T) should be classified as the type strain of a novel Thermomonas species, for which the name Thermomonas koreensis sp. nov. is proposed.

A yellowish-brown bacterium was isolated from enrichment cultures inoculated with seawater samples from the eastern coast of India (Visakhapatnam) under photoheterotrophic conditions. Enrichment and isolation in a medium containing 2 % NaCl (w/v) yielded strain JA128T, which has ovoid to rod-shaped cells, also forms chains and is non-motile. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA128T clusters with the Alphaproteobacteria and the sequence similarity with its closest relatives, Rhodovulum iodosum and Rhodovulum sulfidophilum, was 95 %. Strain JA128T contained vesicular intracytoplasmic membranes, bacteriochlorophyll a and carotenoids of the spheroidene series. Strain JA128T was mesophilic, slightly acidophilic, slightly halophilic and grew photoheterotrophically with a number of organic compounds as carbon source and electron donor. It was unable to grow photoautotrophically, chemoautotrophically or by fermentative modes. It did not utilize sulfide, thiosulfate or hydrogen as electron donors. Thiamine was required as a growth factor. Based on the 16S rRNA gene sequence analysis, morphological and physiological characteristics, strain JA128T was significantly different from other species of the genus Rhodovulum and was recognized as a novel species for which the name Rhodovulum marinum sp. nov. is proposed. The type strain is JA128T (=ATCC BAA 1215T=CCUG 52183T=JCM 13300T).

A Gram-negative, non-motile, non-spore-forming, rod-shaped bacterium (strain Y9T) was isolated from a contaminated culture of the phototrophic bacterium Rhodopseudomonas palustris, and was investigated using a polyphasic taxonomic approach. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain Y9T belonged to the order Rhizobiales in the Alphaproteobacteria. Comparison of phylogenetic data indicated that it was most closely related to Pleomorphomonas oryzae (98.5 % similarity of 16S rRNA gene sequence), and the phylogenetic distance from any other species of the order Rhizobiales with a validly published name was greater than 7.5 % (i.e. less than 92.5 % similarity). The predominant ubiquinone was Q-10 and the major fatty acids were C18 : 1, C16 : 0, C19 : 0 cyclo ω8c and C18 : 0. The G+C content of genomic DNA of strain Y9T was 65.1 mol%. The results of DNA–DNA hybridization in combination with chemotaxonomic and physiological data demonstrated that strain Y9T represents a novel species within the genus Pleomorphomonas, for which the name Pleomorphomonas koreensis sp. nov. is proposed. The type strain is Y9T (=KCTC 12246T=NBRC 100803T)

Rickettsia sp. strain AT-1T was isolated from Amblyomma testudinarium ticks in Japan in 1993. Comparative analysis of sequences obtained from 16S rRNA, gltA, ompA, ompB and sca4 gene fragments demonstrated those from AT-1T to be markedly different from those of other members of the spotted fever group. Using mouse serotyping, it was also observed that Rickettsia sp. strain AT-1T was different from other Rickettsia species with validly published names. Such genotypic and phenotypic characteristics warrant its classification as a representative of a novel species, for which the name Rickettsia tamurae sp. nov. is proposed, with the type strain AT-1T (=CSUR R1T).

A non-pigmented, motile, Gram-negative bacterium designated MTCC 4195T was isolated from surface-sterilized seeds and plant tissue from deep-water rice (Oryza sativa) cultivated in Suraha Tal Lake in northern India. This isolate was shown to reinfect and colonize deep-water rice endophytically. The highest level of 16S rRNA sequence similarity (96.8 %) to strain MTCC 4195T was shown by Ochrobactrum gallinifaecis DSM 15295T. Strain MTCC 4195T utilized γ-hydroxybutyric acid, adonitol, d-glucosaminic acid and arabinose as carbon sources, but failed to use gentiobiose or citrate. The cell-wall fatty acids of strain MTCC 4195T were characterized by the presence of a relatively large proportion of C18 : 1 ω7c and a relative small proportion of C16 : 0 in comparison with Ochrobactrum species. DNA–DNA relatedness studies showed less than 52 % binding with the DNAs of type strains of other species of the genus Ochrobactrum. On the basis of phenotypic and genotypic characteristics and the results of 16S rRNA gene sequence analysis, the novel species Ochrobactrum oryzae sp. nov. is proposed, with MTCC 4195T (=DSM 17471T) as the type strain.

Six strains of extremely halophilic bacteria were isolated from several crystallizer ponds of the Maras solar salterns in the Peruvian Andes. On the basis of 16S rRNA gene sequence similarity, G+C contents and DNA–DNA hybridization results, the six isolates constituted a genomically homogeneous group affiliated with the Gammaproteobacteria. The closest relatives were members of the halophilic genera Halovibrio and Halospina, which showed 16S rRNA gene sequence similarities below 97 % and whole-genome hybridization levels below 33 % for the type strain, 7Sm5T. From the genomic and phenotypic properties of the six novel isolates and phylogenetic reconstruction based on 16S rRNA gene sequence analysis, they can be considered to represent a novel genus within the Gammaproteobacteria. On the basis of the taxonomic study, a novel genus, Salicola gen. nov., is proposed containing the single species Salicola marasensis sp. nov., which is the type species. The type strain of Salicola marasensis is 7Sm5T (=CECT 7107T=CIP 108835T).

Four novel bacterial strains were isolated from cryogenic tubes used to collect air samples at altitudes of 24, 28 and 41 km. The four strains, 24KT, 28KT, 41KF2aT and 41KF2bT, were identified as members of the genus Bacillus. Phylogenetic analysis based on 16S rRNA gene sequences indicated that three of the strains, 24KT, 28KT and 41KF2aT, are very similar to one another (>98 % sequence similarity) and show a similarity of 98–99 % with Bacillus licheniformis and 98 % with Bacillus sonorensis. DNA–DNA hybridization studies showed that strains 24KT, 28KT and 41KF2aT exhibit <70 % similarity with each other and with B. licheniformis and B. sonorensis. Differences in phenotypic and chemotaxonomic characteristics between the novel strains and B. licheniformis and B. sonorensis further confirmed that these three isolates are representatives of three separate novel species. Strain 41KF2bT showed 100 % 16S rRNA gene sequence similarity to Bacillus pumilus, but differed from its nearest phylogenetic neighbour in a number of phenotypic and chemotaxonomic characteristics and showed only 55 % DNA–DNA relatedness. Therefore, the four isolates represent four novel species for which the names Bacillus aerius sp. nov. (type strain, 24KT=MTCC 7303T=JCM 13348T), Bacillus aerophilus sp. nov. (type strain, 28KT=MTCC 7304T=JCM 13347T), Bacillus stratosphericus sp. nov. (type strain, 41KF2aT=MTCC 7305T=JCM 13349T) and Bacillus altitudinis sp. nov. (type strain, 41KF2bT=MTCC 7306T=JCM 13350T) are proposed.

A Gram-positive, spore-forming bacillus was isolated from a sample taken from an approximately 2000-year-old shaft-tomb located in the Mexican state of Jalisco, near the city of Tequila. Tentative identification using conventional biochemical analysis consistently identified the isolate as Bacillus subtilis. DNA isolated from the tomb isolate, strain 10bT, and closely related species was used to amplify a Bacillus-specific portion of the highly conserved 16S rRNA gene and an internal region of the superoxide dismutase gene (sodA int). Trees derived from maximum-likelihood methods applied to the sodA int sequences yielded non-zero branch lengths between strain 10bT and its closest relative, whereas a comparison of a Bacillus-specific 546 bp amplicon of the 16S rRNA gene demonstrated 99 % similarity with B. subtilis. Although the 16S rRNA gene sequences of strain 10bT and B. subtilis were 99 % similar, PFGE of NotI-digested DNA of strain 10bT revealed a restriction profile that was considerably different from those of B. subtilis and other closely related species. Whereas qualitative differences in whole-cell fatty acids were not observed, significant quantitative differences were found to exist between strain 10bT and each of the other closely related Bacillus species examined. In addition, DNA–DNA hybridization studies demonstrated that strain 10bT had a relatedness value of less than 70 % with B. subtilis and other closely related species. Evidence from the sodA int sequences, whole-cell fatty acid profiles and PFGE analysis, together with results from DNA–DNA hybridization studies, justify the classification of strain 10bT as representing a distinct species, for which the name Bacillus tequilensis sp. nov. is proposed. The type strain is 10bT (=ATCC BAA-819T=NCTC 13306T).

An unidentified Gram-negative-staining, aerobic, rod-shaped, spore-forming bacterium was isolated from a sample of cerebrospinal fluid. Based on comparative analysis of 16S rRNA gene sequences and phenotypic characteristics, the novel isolate was included in the Bacillus sphaericus-like group. The isolate was closely related to Bacillus odysseyi and Bacillus silvestris, with 96.2 and 94.4 % 16S rRNA gene sequence similarity, respectively. The major fatty acid was iso-C15 : 0 (48 %). The name Bacillus massiliensis sp. nov. is proposed for the novel isolate, with strain 4400831T (=CIP 108446T=CCUG 49529T) as the type strain.

The National Antimicrobial Resistance Monitoring System Laboratory at the Centers for Disease Control and Prevention (CDC) isolated two enterococcus-like strains that were referred to the CDC Streptococcus Laboratory for further identification. The isolates were recovered from human stool samples collected on different occasions from the same individual in Portland (OR, USA) in July 2000. Conventional physiological tests distinguished these strains from all known species of enterococci. Analyses of whole-cell-protein electrophoretic profiles showed the same unique profile for the two isolates, being most similar those of Enterococcus moraviensis and Enterococcus haemoperoxidus albeit not close enough to allow conclusive inclusion in any enterococcal species. Both isolates gave positive results in tests using the AccuProbe Enterococcus genetic probe, and Lancefield extracts reacted with CDC group D antiserum. Comparative 16S rRNA gene sequencing studies also revealed that these strains were closely related to the species E. moraviensis (99.6 % identity). The results of DNA–DNA relatedness experiments confirmed that these strains represented a single novel taxon. The highest level of DNA–DNA relatedness found between the novel taxon and any of the currently recognized species of Enterococcus was 32 %, for both E. moraviensis and E. haemoperoxidus. On the basis of this evidence, it is proposed that these stool isolates constitute a novel species, for which the name Enterococcus caccae sp. nov. is proposed. The type strain is 2215-02T (=SS-1777T=ATCC BAA-1240T=CCUG 51564T).

Two novel spore-forming, Gram-positive, mesophilic, heterotrophic bacteria representing two novel species were isolated from the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) at Pasadena, CA, USA. The incidence of similar strains was examined by screening the growing collection of isolates (~400 strains) obtained from the JPL-SAF using species-specific PCR primer sets designed from the 16S rRNA gene sequences of strains SAFN-016T and SAFN-007T. Phylogenetic analysis of 16S rRNA gene sequences placed these novel isolates within the genus Paenibacillus. Two strains, SAFN-016T and SAFN-125, shared 98 % 16S rRNA gene sequence similarity with Paenibacillus timonensis and 97 % similarity with Paenibacillus macerans. Strain SAFN-007T showed 95.2 % 16S rRNA gene sequence similarity with Paenibacillus kobensis, its nearest phylogenetic neighbour. The results of DNA–DNA hybridization, physiological tests and biochemical analysis allowed genotypic and phenotypic differentiation of the isolates from currently recognized Paenibacillus species. Strain SAFN-007T and strains SAFN-016T and SAFN-125 are representatives of two separate novel species, for which the names Paenibacillus pasadenensis sp. nov. (type strain SAFN-007T=ATCC BAA-1211T=NBRC 101214T) and Paenibacillus barengoltzii sp. nov. (type strain SAFN-016T=ATCC BAA-1209T=NBRC 101215T) are proposed.

A novel thermophilic bacterium, strain KW1T, was isolated from a coastal hydrothermal field on the Satsuma Peninsula, Kagoshima Prefecture, Japan. The variably Gram-stained cells were motile rods with flagella, did not form spores and proliferated at 52–78 °C (optimum, 70 °C), pH 5–8 (optimum, pH 7) and 0–4.5 % NaCl (optimum, 1.0 %). The novel isolate was a strictly aerobic heterotroph that utilized complex proteinaceous substrates as well as a variety of carboxylic acids and amino acids. The G+C content of the genomic DNA was 70.8 mol%. Analysis of 16S rRNA gene sequences indicated that strain KW1T is closely related to Thermaerobacter subterraneus C21T (98.4 % sequence similarity). However, the DNA–DNA hybridization value for strain KW1T and T. subterraneus ATCC BAA-137T was below 46 %. On the basis of the molecular and physiological traits of strain KW1T, it represents a novel species of the genus Thermaerobacter, for which the name Thermaerobacter litoralis sp. nov. is proposed. The type strain is KW1T (=JCM 13210T=DSM 17372T).

A polyphasic study revealed taxonomic heterogeneity among reference strains of the species Lactobacillus brevis. Representative strains of L. brevis and related taxa were investigated by partial sequence analysis of the housekeeping gene encoding the alpha-subunit of phenylalanyl-tRNA synthase (pheS). Species-specific clusters were delineated for all taxa studied except for two L. brevis strains, LMG 11494 and LMG 11984, respectively isolated from cheese and wheat, which occupied a distinct position. Their phylogenetic affiliation was determined using 16S rRNA gene sequence analysis and it was found that both strains (with 99.9 % gene sequence similarity between them) belonged to the Lactobacillus buchneri group, with nearest neighbours Lactobacillus hammesii and L. brevis (gene sequence similarities of 99.2 and 98.1 %, respectively). Further genotypic and phenotypic studies, including fluorescent amplified fragment length polymorphism, DNA–DNA hybridization and DNA G+C content, clearly demonstrated that the two strains represent a single novel taxon for which the name Lactobacillus parabrevis sp. nov. is proposed (type strain LMG 11984T=ATCC 53295T).

Potato purple top wilt (PPT) is a devastating disease that occurs in various regions of North America and Mexico. At least three distinct phytoplasma strains belonging to three different phytoplasma groups (16SrI, 16SrII and 16SrVI) have been associated with this disease. A new disease with symptoms similar to PPT was recently observed in Texas and Nebraska, USA. Two distinct phytoplasma strain clusters were identified. One belongs to the 16SrI phytoplasma group, subgroup A, and the other is a novel phytoplasma that is most closely related to, and shares 96.6 % 16S rRNA gene sequence similarity with, a member of group 16SrXII. Phylogenetic analysis of 16S rRNA gene sequences of the novel PPT-associated phytoplasma strains, previously described ‘Candidatus Phytoplasma’ organisms and other distinct unnamed phytoplasmas indicated that the novel phytoplasma, termed American potato purple top wilt (APPTW) phytoplasma, represents a distinct lineage and shares a common ancestor with stolbur phytoplasma, ‘Candidatus Phytoplasma australiense’, ‘Candidatus Phytoplasma japonicum’, ‘Candidatus Phytoplasma fragariae’, bindweed yellows phytoplasma (IBS), ‘Candidatus Phytoplasma caricae’ and ‘Candidatus Phytoplasma graminis’. On the basis of unique 16S rRNA gene sequences and biological properties, it is proposed that the APPTW phytoplasma represents ‘Candidatus Phytoplasma americanum’, with APPTW12-NE as the reference strain.