- Volume 57, Issue 5, 2007

The taxonomic status of a bacterial isolate from the sludge of a wastewater treatment plant was characterized by using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Gordonia, fatty acids C16 : 0 and C18 : 0 (found by pyrolysis gas chromatography) and a dihydrogenated menaquinone with nine isoprene units [MK-9(H2)] as the predominant menaquinone. The genus assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that the novel isolate constitutes a hitherto unknown subline within the genus Gordonia, displaying 95.9 to 97.6 % gene sequence similarity to the recognized species of the genus. The novel isolate was distinguished from the type strains of phylogenetically related species by using a set of phenotypic features. The genotypic and phenotypic data show that the new strain merits classification as a novel species of the genus Gordonia, for which the name Gordonia malaquae sp. nov. is proposed. The type strain is IMMIB WWCC-22T (=DSM 45064T=CCUG 53555T).

A novel strain, C-138T, belonging to the genus Corynebacterium was isolated from a severe thigh liposarcoma infection and its differentiation from Corynebacterium xerosis and Corynebacterium freneyi is described. Analysis of 16S rRNA gene sequences, rpoB sequences and the PCR profile of the 16S–23S spacer regions was not conclusive enough to differentiate strain C-138T from C. xerosis and C. freneyi. However, according to DNA–DNA hybridization data, strain C-138T constitutes a member of a distinct novel species. It can be differentiated from strains of C. xerosis and C. freneyi by colony morphology, the absence of α-glucosidase and some biochemical characteristics such as glucose fermentation at 42 °C and carbon assimilation substrates. The name Corynebacterium hansenii sp. nov. is proposed for this novel species; the type strain is C-138T (=CIP 108444T=CCUG 53252T).

A Gram-negative, pleomorphic, extremely halophilic archaeon, designated strain XH-70T, was isolated from the saline Lake Xilinhot, in Inner Mongolia, China. It formed small (0.9–1.5 mm), red-pigmented, elevated colonies on agar medium. The strain required at least 2.5 M NaCl and 5 mM Mg2+ for growth. The 16S rRNA gene sequence analysis indicated that strain XH-70T belongs to the family Halobacteriaceae, showing 99.5 % similarity to the type strain of Halovivax asiaticus and 94.7 and 94.6 % similarity, respectively, to the type strains of Natronococcus amylolyticus and Natronococcus occultus. Polar lipid analysis supported the placement of strain XH-70T in the genus Halovivax. DNA–DNA hybridization studies (32 % with Halovivax asiaticus CGMCC 1.4248T), as well as biochemical and physiological characterization, allowed strain XH-70T to be differentiated from Halovivax asiaticus. A novel species, Halovivax ruber sp. nov., is therefore proposed to accommodate this strain. The type strain is XH-70T (=CGMCC 1.6204T=DSM 18193T=JCM 13892T).

A Gram-negative, aerobic, neutrophilic and extremely halophilic archaeon (strain AJ201T), isolated from Ayakekum salt lake on the Qinghai–Tibet Plateau, was investigated by a polyphasic approach. The DNA G+C content of strain AJ201T was 65.7 mol%. The major polar lipid profile and phylogenetic analysis based on 16S rRNA gene sequences supported the allocation of the strain to the genus Halorubrum. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain AJ201T from closely related species. Therefore, strain AJ201T represents a novel species of the genus Halorubrum, for which the name Halorubrum arcis sp. nov. is proposed. The type strain is strain AJ201T (=CGMCC 1.5343T=JCM 13916T).

Filamentous bacteria frequently occurring in the pelagic zone of natural freshwater lakes and ponds were previously identified as being related to Haliscomenobacter hydrossis based upon their 16S rRNA gene sequences. These bacteria exhibit a specific morphology characterized by the formation of straight, stick-like filaments of variable length (5 to >100 μm) and quite stable, but narrow, width (0.25 to 0.35 μm). Bacteria with these morphological characteristics form a monophyletic but broad phylogenetic group with a maximal divergence of 16S rRNA gene sequences of 12.0 %. This monophyletic group consists of at least three monophyletic subclusters. H. hydrossis is affiliated to one of these subclusters and represents the sole recognized species affiliated to the broad monophyletic group. ‘Candidatus Haliscomenobacter calcifugiens' and ‘Candidatus Aquirestis calciphila’ are uncultured representatives of the other two subclusters and have 16S rRNA gene sequence dissimilarities of 5.4 % and 8.2 %, respectively, with the type strain of H. hydrossis. ‘Candidatus H. calcifugiens' and ‘Candidatus A. calciphila’ have a 16S rRNA gene sequence dissimilarity of 8.5 %. These large ribosomal divergences justify the classification of these environmentally important bacteria as a novel species and a new genus, respectively. Intensive attempts to cultivate these filamentous bacteria have resulted in the establishment of mixed cultures, however, attempts to establish pure cultures have failed.

Six strains (CB7T, CB18, CB23, CB26, CB28 and CB35T) were isolated from human faeces. Based on phylogenetic analysis, phenotypic characteristics, cellular fatty acid profiles and menaquinone profiles, these strains could be included within the genus Prevotella and made up two clusters. 16S rRNA gene sequence analysis indicated that five strains were most closely related to Prevotella veroralis, sharing about 92 % sequence similarity; the remaining strain was most closely related to Prevotella shahii, sharing about 90 % sequence similarity. All six strains were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-negative rods. The cellular fatty acid compositions of the six strains differed significantly from those of other Prevotella species. Five strains (CB7T, CB18, CB23, CB26 and CB28) contained dimethyl acetals and the major menaquinones of these strains were MK-11, MK-12 and MK-13. The major menaquinones of CB35T were MK-12 and MK-13. Based on phenotypic and phylogenetic findings, two novel species, Prevotella copri sp. nov. and Prevotella stercorea sp. nov., are proposed, representing the two different strain clusters. The DNA G+C contents of strains CB7T and CB35T were 45.3 and 48.2 mol%, respectively. The type strains of P. copri and P. stercorea are CB7T (=JCM 13464T=DSM 18205T) and CB35T (=JCM 13469T=DSM 18206T), respectively.

A Gram-negative, rod-shaped, Flavobacterium-like bacterial strain, DS-20T, was isolated from soil from the island of Dokdo, Korea, and subjected to a polyphasic taxonomic study. Strain DS-20T grew optimally at pH 6.5–7.0 and 25 °C. It contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1 ω9c as the major fatty acids. The DNA G+C content was 38.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-20T belonged to the genus Flavobacterium. Levels of 16S rRNA gene sequence similarity between strain DS-20T and the type strains of recognized Flavobacterium species were below 94.9 %. Strain DS-20T differed from phylogenetically related Flavobacterium species in several phenotypic characteristics. On the basis of its phenotypic and phylogenetic distinctiveness, strain DS-20T was classified in the genus Flavobacterium as representing a novel species, for which the name Flavobacterium terrigena sp. nov. is proposed. The type strain is DS-20T (=KCTC 12761T=DSM 17934T).

A strictly aerobic, Gram-negative, gliding, dull-orange-pigmented, rod-shaped bacterium, designated strain Shu-F-UV2-2T, was isolated from sediment (Carp Island, Republic of Palau) and was the focus of a polyphasic taxonomic study. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated to the family ‘Flammeovirgaceae’ of the phylum Bacteroidetes and that it showed highest sequence similarity (85.5 %) to Flammeovirga yaeyamensis NBRC 100898T. The novel isolate could be differentiated phenotypically and physiologically from recognized members of the family ‘Flammeovirgaceae’. The G+C content of the DNA was 43.0 mol%, MK-7 was the major menaquinone and iso-C15 : 0, C16 : 1 ω7c and C16 : 1 ω5c were the major fatty acids. On the basis of this polyphasic evidence, it was concluded that strain Shu-F-UV2-2T represents a novel species in a new genus of the family ‘Flammeovirgaceae’, for which the name Perexilibacter aurantiacus gen. nov., sp. nov. is proposed. The type strain is Shu-F-UV2-2T (=MBIC06993T=IAM 15413T=KCTC 12867T).

A Gram-negative, yellow-pigmented, rod-shaped bacterial strain (Mok-17T) was isolated from marine sediment sampled in Okinawa Island, Japan. Based on analysis of the almost complete sequence of its 16S rRNA gene, strain Mok-17T was found to belong to the family Flavobacteriaceae. Strain Mok-17T showed highest 16S rRNA gene sequence similarity (91 %) to Leeuwenhoekiella marinoflava and Robiginitalea biformata. In a phylogenetic tree based on the 16S rRNA gene, strain Mok-17T formed a deep branch distinct from all other organisms in the family Flavobacteriaceae. The major quinone was MK-6 and the major fatty acids were iso-15 : 0, iso-15 : 1, iso-17 : 0 3-OH and summed feature 3 (16 : 1ω7c and/or iso-15 : 0 2-OH). The DNA G+C content was 37 mol%. The phylogenetic distance to the type strains of all recognized species in the family Flavobacteriaceae and the phenotypic properties of strain Mok-17T supported its classification as representing a novel species in a new genus, for which the name Galbibacter mesophilus gen. nov., sp. nov. is proposed. The type strain is Mok-17T (=NBRC 101624T=CIP 109219T).

A non-motile, Gram-negative, boron-tolerant and alkaliphilic bacterium was isolated from soil of the Hisarcik area in the Kutahya Province of Turkey that was naturally high in boron minerals. The novel isolate, designated T-22T, formed rod-shaped cells, was catalase- and oxidase-positive and tolerated up to 300 mM boron. The strain also survived on agar medium containing up to 3 % (w/v) NaCl. The pH range for growth of this strain was 6.5–10.0 (optimum pH 8.0–9.0) and the temperature range was 16–37 °C (optimum 28–30 °C). Phylogenetic analysis based on 16S rRNA gene sequences revealed a clear affiliation with the genus Chimaereicella, with 97.4 % sequence similarity to Chimaereicella alkaliphila AC-74T, which was the highest similarity among cultivated bacteria. The DNA–DNA relatedness with C. alkaliphila AC-74T was 28.3 %. The major respiratory quinone system was MK-7 and the predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 1 ω9c, iso-C17 : 0 3-OH and summed feature 3 (iso-C15 : 0 2-OH and/or iso-C16 : 1 ω7c). The DNA G+C content was 42.5 mol%. Based on the phylogenetic analysis and physiological, chemotaxonomic and genetic data, we concluded that strain T-22T should be classified in the genus Chimaereicella, and we propose the name Chimaereicella boritolerans sp. nov. for this novel species. The type strain is strain T-22T (=DSM 17298T=NBRC 101277T=ATCC BAA-1189T).

An obligately aerobic, Gram-negative, non-motile, pale-pink-pigmented, rod-shaped strain, designated Shu-9-SY12-35CT, was isolated from seawater in Jodogahama, Iwate, Japan, and was subjected to a polyphasic taxonomic examination. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the family ‘Flexibacteraceae’ of the phylum Bacteroidetes and that it showed highest sequence similarity (86.4 %) with Dyadobacter hamtensis HHS 11T. The novel isolate is phenotypically and physiologically different from strains described previously. The G+C content of the DNA was 56.3 mol%, MK-7 was the major menaquinone and iso-C15 : 0, C16 : 1 ω7c and iso-C17 : 0 3-OH were the major fatty acids. On the basis of polyphasic taxonomic studies, it was concluded that strain Shu-9-SY12-35CT represents a new genus and species of the family ‘Flexibacteraceae’, for which the name Persicitalea jodogahamensis gen. nov., sp. nov. is proposed. The type strain of Persicitalea jodogahamensis is Shu-9-SY12-35CT (=MBIC07417T=IAM 15412T=KCTC 12866T).

A novel, strictly aerobic, heterotrophic, gliding, Gram-negative, oxidase-, catalase-, β-galactosidase- and alkaline phosphatase-positive marine bacterium, designated strain KMM 6220T, was isolated from seawater and studied by using a polyphasic taxonomic approach. The DNA G+C content of strain KMM 6220T was 59.9 mol%. The predominant fatty acids were iso-C15 : 1, iso-C15 : 0, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH and C16 : 1 ω7/iso-C15 : 0 2-OH. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain KMM 6220T formed a cluster with the misclassified strains [Flexibacter] aggregans NBRC 15974 and [Flexibacter] tractuosus NBRC 16035 and with the type strains of Reichenbachiella agariperforans and Roseivirga ehrenbergii with levels of similarity of 95.9, 94.4, 92.0 and 91.8 %, respectively. On the basis of its phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, strain KMM 6220T is considered to represent a novel species of a new genus in the phylum Bacteroidetes, for which the name Fulvivirga kasyanovii gen. nov., sp. nov. is proposed. The type strain of the type species is KMM 6220T (=CCTCC AB 206119T=KCTC 12832T).

A marine bacterium, DOKDO 007T, was isolated from the rhizosphere of the marine alga Ecklonia kurome collected from Dokdo Island, Korea, in October 2004. The strain produced orange-coloured colonies on marine agar 2216. 16S rRNA gene sequence analysis indicated that the novel isolate belonged to the family Flavobacteriaceae and showed relatively high sequence similarities with members of the genus Muricauda (92.0–94.0 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the novel isolate shared a lineage with members of the genera Muricauda and Costertonia. Cells were aerobic, Gram-negative rods producing non-diffusible carotenoid pigments. In contrast to all other members of the family Flavobacteriaceae, cells of DOKDO 007T were motile by means of a polar flagellum. Optimal growth occurred in the presence of 3.5–4 % (w/v) sea salts (corresponding to 2.7–3.1 % NaCl), at pH 8 and at temperatures of 26–29 °C. The novel strain required Ca2+ ions in addition to NaCl for growth. The dominant fatty acids were iso-15 : 0, iso-15 : 1ω10c and 10-methyl-16 : 0. The major respiratory quinone was MK-6. The DNA G+C content was 56.3 mol%, an unusually high value for members of the family Flavobacteriaceae. On the basis of these polyphasic taxonomic data, strain DOKDO 007T should be classified as representing a new genus and novel species in the family Flavobacteriaceae, for which the name Flagellimonas eckloniae gen. nov., sp. nov. is proposed. The type strain is DOKDO 007T (=KCCM 42307T=JCM 13831T).

The taxonomic relationship between [Flexibacter] aggregans IAM 14894T and Flexithrix dorotheae NBRC 15987T was investigated by means of DNA–DNA hybridization and phenotypic characteristics. On the basis of these results, it is proposed that Flexibacter aggregans ( Lewin 1969 ) Leadbetter 1974 be considered a later heterotypic synonym of Flexithrix dorotheae Lewin 1970 . Emended descriptions of the species Flexithrix dorotheae and the genus Flexithrix are also given.

A yellow-coloured, aerobic, Gram-negative, rod-shaped bacterial strain, designated B-IT, was isolated from the water of a shrimp (Litopenaeus vannamei) mariculture pond in Taiwan. No species with a validly published name showed 16S rRNA gene sequence similarity of more than 96.5 % to this novel isolate. The highest sequence similarities displayed by strain B-IT (93.2–96.1 %) were to members of the genus Tenacibaculum. The phenotypic properties of this organism were consistent with its classification in the genus Tenacibaculum. The novel isolate could be distinguished from all Tenacibaculum species by several phenotypic characteristics. The major fatty acids were iso-C15 : 0 (22 %), summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH; 21.3 %), iso-C17 : 0 3-OH (12.7 %) and iso-C15 : 1 (8.7 %). The G+C content of the genomic DNA was 35.2 mol%. Hence, genotypic and phenotypic data demonstrate that strain B-IT should be classified within a novel species in the genus Tenacibaculum, for which the name Tenacibaculum litopenaei sp. nov. is proposed. The type strain is B-IT (=BCRC 17590T=LMG 23706T).

An obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium, designated strain 04OKA010-24T, was isolated from seawater surrounding the hard coral Galaxea fascicularis L., collected at Majanohama, Akajima, Japan, and was subjected to a polyphasic taxonomic study. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that the new strain represented a member of the phylum ‘Verrucomicrobia’ and shared 84–95 % sequence similarity with cultivated strains of ‘Verrucomicrobia’ subdivision 4. Amino acid analysis of the cell-wall hydrolysate indicated the absence of muramic acid and diaminopimelic acid, which suggested that the strain did not contain peptidoglycan in the cell wall. The G+C content of the DNA was 53.9 mol%. MK-7 was the major menaquinone and C14 : 0, C18 : 1 ω9c and C18 : 0 were the major fatty acids. On the basis of these data, it was concluded that strain 04OKA010-24T represents a novel species in a new genus in subdivision 4 of the phylum ‘Verrucomicrobia’, for which the name Coraliomargarita akajimensis gen. nov., sp. nov. is proposed. The type strain of Coraliomargarita akajimensis is 04OKA010-24T (=MBIC06463T=IAM 15411T=KCTC 12865T).

A Gram-negative, short rod to oval-shaped bacterium (strain MW2aT) was isolated from the surface of leaves of the black mangrove Avicennia germinans and subjected to a polyphasic taxonomic study. Strain MW2aT was moderately halophilic, growing at NaCl concentrations in the range 0–25 % (w/v) with optimum growth at 5 % (w/v) NaCl. Growth occurred at 12–40 °C (optimum, 30–35 °C) and at pH 5.0–9.0 (optimum, pH 7.0–8.0). Strain MW2aT was strictly aerobic. Phylogenetic analysis based on the 16S rRNA gene showed that the strain belongs to the genus Halomonas. The closest relative was Halomonas marisflavi, with 98.6 % 16S rRNA gene sequence similarity. The DNA G+C content of strain MW2aT was 61.5 mol%, which is in the range of values for Halomonas species. DNA–DNA hybridization with H. marisflavi showed a relatedness of 42 % and lower values were obtained with respect to other related Halomonas species. The major fatty acids were C16 : 0, C19 : 0 cyclo ω8c, C18 : 1 ω7c and C12 : 0 3-OH. Overall, the phenotypic, genotypic and phylogenetic results presented in this study demonstrate that strain MW2aT represents a novel species within the genus Halomonas. The name Halomonas avicenniae sp. nov. is proposed, with strain MW2aT (=CECT 7193T=CCM 7396T) as the type strain.