- Volume 57, Issue 7, 2007

Twenty-three acetic acid bacteria, isolated from traditional heap fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. The isolates were catalase-positive, oxidase-negative, Gram-negative rods. They oxidized ethanol to acetic acid and were unable to produce 2-ketogluconic acid, 5-ketogluconic acid and 2,5-diketogluconic acid from glucose; therefore, they were tentatively identified as Acetobacter species. 16S rRNA gene sequencing and phylogenetic analysis confirmed their position in the genus Acetobacter, with Acetobacter syzygii and Acetobacter lovaniensis as their closest phylogenetic neighbours. (GTG)5-PCR fingerprinting grouped the strains in a cluster that did not contain any type strains of members of the genus Acetobacter. DNA–DNA hybridization with the type strains of all recognized Acetobacter species revealed DNA–DNA relatedness values below the species level. The DNA G+C contents of three selected strains were 56.9–57.3 mol%. The novel strains had phenotypic characteristics that enabled them to be differentiated from phylogenetically related Acetobacter species, i.e. they were motile, did not produce 2-ketogluconic acid or 5-ketogluconic acid from glucose, were catalase-positive and oxidase-negative, grew on yeast extract with 30 % glucose, grew on glycerol (although weakly) but not on maltose or methanol as carbon sources, and did not grow with ammonium as sole nitrogen source and ethanol as carbon source. Based on the genotypic and phenotypic data, the isolates represent a novel species of the genus Acetobacter for which the name Acetobacter ghanensis sp. nov. is proposed. The type strain is R-29337T (=430AT=LMG 23848T=DSM 18895T).

A Gram-negative, chemoheterotrophic, strictly aerobic, alkaliphilic, rod-shaped marine bacterium, designated HTCC2654T, was isolated from the western Sargasso Sea by using a dilution-to-extinction culturing method. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HTCC2654T belonged to the Roseobacter clade of the order Rhodobacterales. The 16S rRNA gene sequence similarity of the strain with respect to other members of the Roseobacter clade ranged from 90.4 to 95.1 %. In the phylogenetic analyses, the strain formed an independent phyletic line and could not be assigned to any other known genera of the Rhodobacterales. The DNA G+C content of strain HTCC2654T was 61.7 mol% by HPLC and 64.1 mol% from genome sequences. The predominant constituents of the cellular fatty acids were C16 : 0 2-OH (27.3 %), 11-methyl C18 : 1 ω7c (19.6 %) and C18 : 1 ω7c (17.3 %), and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine, which served to differentiate the strain from other members of the Roseobacter clade. On the basis of the taxonomic data obtained in this study, strain HTCC2654T represents a novel genus and species, for which the name Maritimibacter alkaliphilus gen. nov., sp. nov. is proposed. The type strain is HTCC2654T (=KCCM 42376T=NBRC 102057T).

A bacterial strain named IMCC1877T was obtained from surface seawater collected near the coast of Deokjeok island (Yellow Sea), using a standard dilution-plating method. The strain was Gram-negative, chemoheterotrophic and facultatively anaerobic, requiring NaCl, and cells were motile rods with a single polar flagellum. Colonies on marine agar were very small (average diameter 0.1 mm). Based on 16S rRNA gene sequences, the most closely related species to strain IMCC1877T was Marinobacterium stanieri (93.7 % sequence similarity to the type strain). Phylogenetic analyses based on 16S rRNA gene sequences showed that this marine isolate belonged to the order Oceanospirillales and formed an independent phyletic line within the clade forming the genus Marinobacterium. The DNA G+C content of the strain was 60.7 mol% and the predominant constituents of the cellular fatty acids were C18 : 1 ω7c (36.6 %), C16 : 1 ω7c and/or iso-C15 : 0 2-OH (26.7 %) and C16 : 0 (24.3 %). Based on the taxonomic data, only a distant relationship could be established between strain IMCC1877T and other Marinobacterium species; the strain therefore represents a novel species of the genus Marinobacterium, for which the name Marinobacterium litorale sp. nov. is proposed. The type strain is IMCC1877T (=KCTC 12756T=LMG 23872T).

Two yeasts strains, Y-31T and Y-20B, pertaining to a previously unknown yeast species were isolated from bark of cork oak in Spain. Physiological characterization revealed a pattern of assimilation of carbon and nitrogen compounds compatible with members of the genus Rhodotorula. From sequence analysis of the D1/D2 region of the 26S rRNA gene, Rhodotorula cycloclastica and Rhodotorula philyla were related to the unknown species. Phylogenetic reconstruction based on the D1/D2 region of the 26S rRNA gene showed that the novel species clustered in a branch together with R. cycloclastica. The name Rhodotorula subericola sp. nov. is proposed, with isolate Y-31T (=CECT 11976T=CBS 10442T) the type strain of this novel taxon in the Microbotryum lineage, subclass Microbotryomycetidae, class Urediniomycetes of basidiomycetous yeasts.

A Gram-positive, spore-forming and moderately halophilic bacterium was isolated from fermented fish (pla-ra) in Thailand. Cells of the isolate, RBU1-1T, were strictly aerobic, motile rods and contained meso-diaminopimelic acid in the cell-wall peptidoglycan. Menaquinone with seven isoprene units (MK-7) was the predominant quinone. This isolate grew at 15–48 °C, pH 5–9 and in 2–30 % NaCl (optimally 10–20 %). The major cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Polar lipid analysis revealed the presence of phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 36.7 mol%. 16S rRNA gene sequence analysis revealed that strain RBU1-1T was a member of the family Bacillaceae, and belonged to a cluster with Filobacillus and Tenuibacillus; strain RBU1-1T showed 16S rRNA gene sequence similarities of 96.0–96.9 % to members of these two genera. Strain RBU1-1T could also be differentiated from members of the genera Filobacillus and Tenuibacillus based on certain phenotypic characteristics such as cell-wall composition, mode of flagellation and growth pH range. Therefore, strain RBU1-1T is considered to represent a novel species in a new genus in the family Bacillaceae, for which the name Piscibacillus salipiscarius gen. nov., sp. nov. is proposed. The type strain of Piscibacillus salipiscarius is RBU1-1T (=JCM 13188T=PCU 270T=TISTR 1571T).

Two anaerobic thermophilic bacteria, designated strains JW/SL824 and JW/SL-NZ826T, were isolated from an acidic volcanic steam outlet on White Island, New Zealand. Cells were rod-shaped, spore-forming, motile and Gram-stain negative, but contained Gram-type positive cell wall. Strain JW/SL-NZ826T utilized various carbohydrates including xylose and glucose. The fermentation end products produced from glucose in the absence of thiosulfate were lactate, ethanol, acetate, CO2 and H2. The temperature range for growth was 34–72 °C, with an optimum at 63–67 °C. The pH60 °C range for growth was 4.0–8.0, with an optimum at 5.0–6.5. The doubling time of strain JW/SL-NZ826T under optimal growth conditions was 2.4 h. The DNA G+C content was 34–35 mol% (HPLC). The two strains reduced up to 1 M thiosulfate to elemental sulfur without sulfide formation, which is a trend typically observed among species belonging to the genus Thermoanaerobacterium. Sulfur globules containing short and long sulfur chains but no S8-ring sulfur were produced inside and outside the cells. Up to 90 mM sulfite was tolerated. This tolerance is assumed to be an adaptation to the geochemistry of the environment of White Island. The 16S rRNA gene sequence analysis, however, indicated that the two strains belonged to the genus Thermoanaerobacter, with similarities in the range 95.6–92.7 %. Therefore, strains JW/SL-NZ824 and JW/SL-NZ826T represent a novel taxon, for which the name Thermoanaerobacter sulfurigignens sp. nov. is proposed, with strain JW/SL-NZ826T (=ATCC 700320T=DSM 17917T) as the type strain. Based on this and previous studies, an emended description of the genus Thermoanaerobacter is given.

A polyphasic taxonomic study of the lactic acid bacteria (LAB) population in three traditional Belgian sourdoughs, sampled between 2002 and 2004, revealed a group of isolates that could not be assigned to any recognized LAB species. Initially, sourdough isolates were screened by means of (GTG)5-PCR fingerprinting. Four isolates displaying unique (GTG)5-PCR patterns were further investigated by means of phenylalanyl-tRNA synthase (pheS) gene sequence analysis and represented a bifurcated branch that could not be allocated to any LAB species present in the in-house pheS database. Their phylogenetic affiliation was determined using 16S rRNA gene sequence analysis and showed that the four sourdough isolates belong to the Lactobacillus plantarum group with Lactobacillus mindensis, Lactobacillus farciminis and Lactobacillus nantensis as closest relatives. Further genotypic and phenotypic studies, including whole-cell protein analysis (SDS-PAGE), amplified fragment length polymorphism (AFLP) fingerprinting, DNA–DNA hybridization, DNA G+C content analysis, growth characteristics and biochemical features, demonstrated that the new sourdough isolates represent a novel Lactobacillus species for which the name Lactobacillus crustorum sp. nov. is proposed. The type strain of the new species is LMG 23699T (=CCUG 53174T).

Three Gram-positive, catalase-negative, motile, rod-shaped strains, designated L486, L489T and L499, were isolated from fermenting cocoa. These organisms produced dl-lactic acid from glucose without gas formation. Ammonia was not produced from arginine. Acid was produced from amygdalin, d-cellobiose, aesculin, d-fructose, d-glucose, d-galactose, d-mannitol, d-mannose, N-acetylglucosamine, l-rhamnose, sucrose, salicin and d-trehalose. The cell walls contained peptidoglycan of the d-meso-diaminopimelic acid type. A 16S rRNA gene sequence analysis revealed that the isolates belong phylogenetically to the genus Lactobacillus and are closely related to Lactobacillus nagelii, Lactobacillus vini and Lactobacillus satsumensis. Low DNA–DNA reassociation values were obtained between the isolates and the phylogenetically closest neighbours. On the basis of the genetic and phenotypic results, the isolates are considered to represent a novel species, for which the name Lactobacillus ghanensis is proposed. The type strain is L489T (=DSM 18630T=CCUG 53453T).

A Gram-negative, rod-shaped, spore-forming and moderately thermophilic bacterium, strain KWC4T, was isolated from a composting reactor. Cells of strain KWC4T were 2.0–5.0 μm long and 0.5–0.7 μm in diameter. Strain KWC4T grew aerobically at 32–61 °C, with optimal growth occurring at 50 °C. It grew at pH 5.6–10.1, with optimal growth at around pH 9.0. The optimum NaCl concentration for growth was almost 0 % (w/v), but strain KWC4T was moderately halotolerant and was able to grow at NaCl concentrations up to 4.4 % (w/v). The DNA G+C content of strain KWC4T was 60.0 mol%. The major fatty acids were iso-16 : 0 (39.0 %) and anteiso-15 : 0 (33.3 %). Based on 16S rRNA gene sequence similarity data, strain KWC4T belonged to the genus Thermobacillus and was related to Thermobacillus xylanilyticus. However, strain KWC4T had a 38 bp insertion sequence located near the 3′ end of its 16S rRNA gene that was not present in T. xylanilyticus. The 16S rRNA gene sequence similarity value between strain KWC4T and T. xylanilyticus was 95.7 %. The DNA–DNA hybridization value between strain KWC4T and T. xylanilyticus strain XET was 66 %. On the basis of phenotypic and genotypic evidence, strain KWC4T (=DSM 18247T=JCM 13945T) is the type strain of a novel species, for which the name Thermobacillus composti sp. nov. is proposed.

An anaerobic, mesophilic, syntrophic, propionate-oxidizing bacterium, strain MGPT, was isolated as a defined co-culture with Methanospirillum hungatei from the methanogenic sludge of a mesophilic upflow anaerobic sludge blanket (UASB) reactor. The strain grew in the presence of propionate, but only in co-culture with methanogens, suggesting that it is an obligately syntrophic bacterium. The optimum temperature for growth was 37 °C, and the optimum pH was between 6.5 and 7.2. Based on comparative 16S rRNA gene sequence analysis, strain MGPT was affiliated with subcluster Ih of ‘Desulfotomaculum cluster I’, in which it was found to be moderately related to known species of the genera Pelotomaculum and Cryptanaerobacter. Similar to known species of the genus Pelotomaculum, strain MGPT could degrade propionate in syntrophy, but had no ability to reduce sulfate, sulfite and thiosulfate. Further phenotypic and genetic studies supported the affiliation of the strain as a novel species in this genus, for which the name Pelotomaculum propionicicum sp. nov. is proposed. The type strain is MGPT (=DSM 15578T=JCM 11929T). The strain has been deposited in the DSM and JCM culture collections as a defined co-culture with Methanospirillum hungatei.

Five coagulase-negative, novobiocin-susceptible staphylococcal strains were isolated from human blood cultures in different German and Belgian medical facilities. A novel species, ‘Staphylococcus pettenkoferi’ was proposed recently to accommodate two of these strains (B3117T and A6664), although the name was not validly published. All five strains belonged to the genus Staphylococcus because they were non-motile, Gram-positive, catalase-positive cocci with peptidoglycan type (A3α type l-lys–gly2–4–l-Ser–Gly), menaquinone pattern (MK-7, MK-6 and MK-8) and major cellular fatty acids (ai-C15 : 0, ai-C17 : 0 and i-C15 : 0) that corresponded to those of staphylococci. Phenotypically, the isolates most closely resembled Staphylococcus capitis subsp. capitis and Staphylococcus auricularis, but they could be distinguished from these species by physiological tests and chemotaxonomic investigations. The results of DNA–DNA hybridization, chemotaxonomic investigations and 16S rRNA gene and RNA polymerase B gene (rpoB) sequence analysis enabled strains B3117T, K6999, 229 and 230 to be differentiated genotypically and phenotypically from known Staphylococcus species, indicating that these isolates are representatives of a novel species. The name Staphylococcus pettenkoferi sp. nov. is proposed for this novel species, with strain B3117T (=CIP 107711T=CCUG 51270T) as the type strain. Due to differences in the results of physiological and chemotaxonomic investigations and DNA–DNA hybridization data, strain A6664 was not included in the description of the novel species.

A Gram-positive, moderately halotolerant bacterium, designated CL-GR16T, was isolated from coastal water off the east coast of Korea. The strain was strictly aerobic, rod-shaped, motile by means of peritrichous flagella and produced ellipsoidal spores. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate represented an independent lineage within Bacillus rRNA group 1, showing 93.6–94.6 % similarity with respect to the genus Ornithinibacillus, 94.0 % with respect to Paucisalibacillus, 91.0–93.5 % with respect to Virgibacillus, 93.2–93.3 % with respect to Salinibacillus and 92.8–93.2 % with respect to Oceanobacillus. The optimum temperature and pH for growth were 30 °C and pH 7.5. Strain CL-GR16T was able to grow at NaCl concentrations from 0 to 14 %, with optimum growth occurring at 0–2 % NaCl. The strain lacked oxidase. The major fatty acids were anteiso-C15 : 0 (65.6 %), anteiso-C17 : 0 (11.0 %) and iso-C15 : 0 (9.1 %). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The predominant menaquinone was MK-7. The G+C content of the DNA was 43 mol%. On the basis of the results of the polyphasic analysis, strain CL-GR16T represents a novel genus and species, for which the name Pelagibacillus goriensis gen. nov., sp. nov. is proposed. The type strain is strain CL-GR16T (=KCCM 42329T=DSM 18252T).

A low-G+C, Gram-positive bacterium, designated CVS-14T, was recovered from a sea salt evaporation pond on the island of Sal in the Cape Verde Archipelago. This organism was catalase- and oxidase-positive. Cells were motile, spore-forming aerobic rods, with an optimum growth temperature of about 35–40 °C and optimum pH between 7.0 and 8.5. Optimal growth occurred in media containing 4–6 % (w/v) NaCl, although the organism was able to grow in medium without added NaCl and in medium containing 16 % NaCl. The cell-wall peptidoglycan was of A1γ type and the major respiratory quinone was menaquinone 7 (MK-7). Major fatty acids were iso-15 : 0, anteiso-15 : 0, iso-17 : 0 and anteiso-17 : 0. The DNA G+C content was 37.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-14T formed a distinct new branch within the radiation of the moderately halophilic bacilli group, forming a separate lineage from species of the genera Salinibacillus, Paucisalibacillus, Oceanobacillus, Lentibacillus and Virgibacillus. Strain CVS-14T showed 16S rRNA gene pairwise similarity values of ~95 % with species of the genus Salinibacillus. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain CVS-14T is considered to represent a novel species in a new genus, for which the name Salirhabdus euzebyi gen. nov., sp. nov. is proposed. The type strain is CVS-14T (=LMG 22839T=CIP 108577T).

A streptococcal-like organism was associated with diseased Channel Catfish Ictalurus punctatus broodstock on four commercial aquaculture operations in the Mississippi Delta. Conventional biochemical testing, 16S rRNA gene sequence analysis and DNA–DNA hybridization distinguished the isolates from these fish from previously published Streptococcus species. Comparative 16S rRNA gene sequencing studies revealed that the isolates were phylogenetically most similar to Streptococcus iniae, Streptococcus uberis and Streptococcus parauberis with divergence ranging from 2.0 to 2.3 %. Streptococcus pyogenes, Streptococcus urinalis, Streptococcus dysgalactiae subsp. dysgalactiae and Streptococcus canis were included in the analysis and showed even greater differences (2.5–3.2 % divergence). DNA relatedness was 22 % or less to the most phylogenetically related species at the optimal temperature. These data suggest that the isolates represent a novel species of Streptococcus for which the name Streptococcus ictaluri sp. nov. is proposed. The type strain is 707-05T (=SO2-1108T=ATCC BAA-1300T=CCUG 52536T).

Two Gram-positive, round-spore-forming, rod-shaped, halophilic bacterial strains, 5B73CT and 5B133E, were isolated from field soil in Kakegawa, Shizuoka, Japan, and were characterized taxonomically using a polyphasic approach. These two strains were found to comprise strictly aerobic, motile rods that formed subterminal endospores. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains 5B73CT and 5B133E are phylogenetically affiliated to the genus Virgibacillus, exhibiting sequence similarities of 94.1–96.4 % with respect to the type strains of Virgibacillus species. The DNA G+C contents of strains 5B73CT and 5B133E were 42.6 and 42.3 mol%, respectively. The cell-wall peptidoglycan type (meso-diaminopimelic acid), the major cellular fatty acids (anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0) and the quinone type (MK-7) of the isolates support their affiliation to the genus Virgibacillus. On the basis of their genotypic and phenotypic characteristics, the isolates represent a novel species of the genus Virgibacillus, for which the name Virgibacillus halophilus sp. nov. is proposed. The type strain is 5B73CT (=IAM 15308T=KCTC 13935T).

The Bacillus subtilis group encompasses the taxa Bacillus subtilis subsp. subtilis, B. licheniformis, B. amyloliquefaciens, B. atrophaeus, B. mojavensis, B. vallismortis, B. subtilis subsp. spizizenii, B. sonorensis, B. velezensis, B. axarquiensis and B. malacitensis. In this study, the taxonomic relatedness between the species B. axarquiensis, B. malacitensis and B. mojavensis was investigated. Sequence analysis of the 16S rRNA gene and the gene for DNA gyrase subunit B (gyrB) confirmed the very high similarities between these three type strains and a reference strain of B. mojavensis (>99 and >97 %, respectively). DNA–DNA hybridization experiments revealed high relatedness values between the type strains of B. axarquiensis, B. malacitensis and B. mojavensis and between these strains and a reference strain of B. mojavensis (83–98 %). Based on these molecular taxonomic data and the lack of phenotypic distinctive characteristics, Bacillus axarquiensis and Bacillus malacitensis should be reclassified as later heterotypic synonyms of Bacillus mojavensis.

Megamonas hypermegale is the sole species of the genus Megamonas included in the List of Prokaryotic Names with Standing in Nomenclature and in the databases of DDBJ, EBI/EMBL and NCBI/GenBank it is placed in the lineage of Bacteroidetes; Bacteroidetes (class); ‘Bacteroidales’; Bacteroidaceae; Megamonas. Phylogenetic analysis based on comparative 16S rRNA gene sequencing showed that this species clustered with species of the family ‘Acidaminococcaceae’ but not with those of the Bacteroidaceae. The genus Megamonas should be placed in the lineage of Firmicutes; Clostridia; Clostridiales; ‘Acidaminococcaceae’; Megamonas.