- Volume 55, Issue 2, 2005

A yellow-pigmented, Gram-negative and aerobic bacterial strain, designated AT1026T, was isolated from a terrestrial sample from the Antarctic. Results of 16S rRNA gene sequence analysis indicated that the Antarctic isolate belonged to the genus Flavobacterium, with the highest sequence similarity to Flavobacterium tegetincola (96·4 %). Cells were non-motile, non-gliding and psychrotolerant, with optimum and maximum temperatures of about 20 and 25 °C. Flexirubins were absent. The major isoprenoid quinone (MK-6), predominant cellular fatty acids (iso-C15 : 1 G, iso-C15 : 0 and a mixture of C16 : 1 ω7c and/or iso-C15 : 0 2-OH) and DNA G+C content (38 mol%) of the Antarctic isolate were consistent with those of the genus Flavobacterium. In contrast, several phenotypic characters can be used to differentiate this isolate from other flavobacteria. The polyphasic data presented in this study indicated that this isolate should be classified as a novel species in the genus Flavobacterium. The name Flavobacterium antarcticum sp. nov. is therefore proposed for the Antarctic isolate; the type strain is AT1026T (=IMSNU 14042T=KCTC 12222T=JCM 12383T).

TXW-1, a Borrelia strain isolated in March 1998 from an adult male Dermacentor variabilis tick feeding on a coyote from Webb county, Texas, USA, was characterized by using randomly amplified polymorphic DNA (RAPD) analysis, RFLP and sequence analysis of flaB and rrs (16S rRNA gene), DNA–DNA hybridization analysis, SDS-PAGE and Western blotting with mAbs. It shows different banding patterns in RFLP analysis of flaB and forms distinct branches in phylogenetic analysis derived from flaB and rrs genes. It differs from other borreliae based on the banding patterns obtained by RAPD analysis. This strain contains a small, 38-kDa endoflagellar protein. DNA–DNA hybridization experiments revealed that the levels of DNA reassociation between TXW-1 and previously described relapsing fever borreliae were 38·64 % (Borrelia turicatae), 38·40 % (Borrelia parkeri), 7·39 % (Borrelia hermsii) and 18·30 % (Borrelia coriaceae). However, the level of DNA relatedness between B. parkeri and B. turicatae was 78·78 %. Sequence analyses of flaB and rrs genes indicate that the similarities of nucleotide sequences among TXW-1 and B. turicatae or B. parkeri are less than that between B. turicatae and B. parkeri, and that the genetic distances among TXW-1 and B. turicatae or B. parkeri are greater than that between B. turicatae and B. parkeri. TXW-1 lacks an ospC gene. Electron microscope observations showed that this spirochaete had different morphological structures compared to previously described relapsing fever borreliae. All the results obtained from the above-mentioned analyses indicate that TXW-1 is different from other described Borrelia species and that it represents a novel species of Borrelia. We have been unable to revive frozen cultures and so can not meet the requirements of the Bacteriological Code to deposit viable type material at two different culture collections. Therefore we use the Candidatus designation; based on these results, the species ‘Candidatus Borrelia texasensis' is proposed.

A Gram-negative, rod-shaped, non-spore-forming bacterium (designated strain Kw05T) was isolated from granules used in the wastewater treatment plant of a beer-brewing factory in Kwang-Ju, Republic of Korea. On the basis of 16S rRNA gene sequence similarity, strain Kw05T was shown to belong to the family Flavobacteriaceae, and was most closely related to Flavobacterium limicola (96·6 %), Flavobacterium hibernum (96·3 %), Flavobacterium hydatis (96·1 %) and Flavobacterium xinjiangense (96·1 %). The G+C content of the genomic DNA of strain Kw05T was 36·2 mol%, within the range of 32–37 mol% for the genus Flavobacterium. Chemotaxonomic data (major menaquinone MK-6; major fatty acids iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and iso-C17 : 1 ω9c) supported the classification of strain Kw05T within the genus Flavobacterium. Kw05T therefore represents a novel species, for which the name Flavobacterium granuli sp. nov. is proposed. The type strain is Kw05T (=KCTC 12201T=IAM 15099T).

Taxonomic studies were performed on seven strains isolated from microbial mats in Antarctic lakes of the McMurdo Dry Valleys. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains are related to the genus Flavobacterium; sequence similarity values with their nearest phylogenetic neighbours ranged from 97·0 to 98·7 %. Results of DNA–DNA hybridization and comparison of repetitive extragenic palindromic DNA-PCR fingerprinting patterns revealed that these strains are members of two distinct species. Genotypic results, together with phenotypic characteristics, allowed these species to be differentiated from related recognized Flavobacterium species. The isolates are psychrophilic, Gram-negative, chemoheterotrophic, rod-shaped cells. Their whole-cell fatty acid profiles are similar and include C15 : 0, C15 : 0 anteiso, C15 : 0 iso, C15 : 1 ω6c, C16 : 0 iso, C16 : 0 iso 3-OH, C16 : 1 iso and summed feature 3 (which comprises C15 : 0 iso 2-OH and/or C16 : 1 ω7c) as the major fatty acid components. On the basis of these results, two novel species are proposed: Flavobacterium fryxellicola sp. nov., consisting of three strains with LMG 22022T (=CIP 108325T) as the type strain; and Flavobacterium psychrolimnae sp. nov., consisting of four strains with LMG 22018T (=CIP 108326T) as the type strain. DNA G+C contents of F. fryxellicola and F. psychrolimnae are 35·2–35·9 and 33·8–34·5 mol%, respectively.

Four Gram-negative, rod-shaped bacterial strains, TF-26T, TF-28, TF-42 and TF-53, were isolated from a tidal flat in the Yellow Sea, Korea, and their taxonomic positions were determined by a polyphasic characterization. The strains grew optimally in the presence of 2–3 % (w/v) NaCl and at 30–37 °C. The predominant menaquinone detected in the four strains was MK-6. These strains contained large amounts of fatty acids C16 : 1 ω7c and/or iso-C15 : 0 2-OH, iso-C15 : 0, iso-C16 : 0 3-OH, C15 : 0 and iso-C17 : 0 3-OH. The DNA G+C contents of the four strains were 32·3–32·8 mol%. Strains TF-26T, TF-28, TF-42 and TF-53 showed 16S rRNA gene sequence similarity levels of 99·8–100 % and DNA–DNA relatedness levels of 82–87 %. The four strains exhibited 16S rRNA gene sequence similarity levels of 95·0–98·0 % to the type strains of the five current Tenacibaculum species, and DNA–DNA relatedness levels between the four strains and two phylogenetic relatives, Tenacibaculum mesophilum DSM 13764T and Tenacibaculum skagerrakense DSM 14836T, were less than 21 %. On the basis of phenotypic, phylogenetic and genetic data, strains TF-26T, TF-28, TF-42 and TF-53 were classified in the genus Tenacibaculum as members of a novel species, for which the name Tenacibaculum lutimaris sp. nov. (type strain, TF-26T=KCTC 12302T=DSM 16505T) is proposed.

Four bacterial strains isolated from the human oral cavity, PPPA19, PPPA21T, PPPA28 and PPPA30, were characterized by determining phenotypic and biochemical features, cellular fatty acid profiles and the phylogenetic position based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that each of the isolates was a member of the genus Prevotella. These strains were related to Prevotella denticola with about 95 % similarity. The strains were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-negative rods. However, the cells of these strains were often cocci (coccobacilli), depending on the cultivation time. Colonies of different sizes were detected on Eggerth Gagnon agar plates for these strains. The cells forming large colonies were cocci, whereas those forming small colonies were cocci and rods. However, 16S rRNA gene sequence comparison of colonies of different sizes revealed that only a single organism was present. Although these strains had phenotypic characteristics that were similar to those of P. denticola JCM 8528, they could be differentiated from P. denticola JCM 8528 by aesculin hydrolysis and d-cellobiose fermentation in API 20A tests. DNA–DNA hybridization experiments revealed the genomic distinction of these four strains with respect to P. denticola JCM 8528. On the basis of these data, a novel Prevotella species, Prevotella multiformis sp. nov., is proposed, with PPPA21T (=JCM 12541T=DSM 16608T) as the type strain.

A Gram-negative bacterium was isolated from a freshwater biofilm developed on a stainless steel surface under a fluid velocity of 0·26 m s−1. The strain, MBRG1.5T, was cultivated on R2A agar and formed pink colonies. Light microscopy and negative staining in a transmission electron microscope showed that the cells were rod-shaped, approximately 2·8–4·1 μm long by 0·9–1·7 μm wide in size and produced large quantities of extracellular fibrillar material. Additionally, following growth in batch culture, transmission electron microscopy showed that many cells plasmolysed. Stationary-phase cells were more variable in size and shape. The DNA G+C content was 40·0 mol%. The most abundant fatty acids were 15 : 0 iso (22·5 %), followed by 16 : 1ω5c (16·9 %) and 15 : 0 iso 2-OH (16·5 %). Phylogenetic analysis of the 16S rRNA gene showed that the strain was a member of the family ‘Flexibacteraceae’ of the Cytophaga–Flavobacterium–Bacteroides group. Phenotypic and genotypic analyses indicated that the strain could not be assigned to any recognized genus; therefore a novel genus and species, Adhaeribacter aquaticus gen. nov., sp. nov., is proposed, with MBRG1.5T (=DSM 16391T=NCIMB 14008T) as the type strain.

A Gram-negative, non-flagellated, non-spore-forming and rod-shaped bacterial strain, SW-152T, was isolated from sea water of the Yellow Sea in Korea, and subjected to a polyphasic taxonomic study. Strain SW-152T grew optimally at 30 °C and in the presence of 2–3 % (w/v) NaCl. It contained MK-7 as the predominant menaquinone and iso-C15 : 0 and iso-C15 : 1 as the major fatty acids. Polar lipids detected in strain SW-152T were phosphatidylethanolamine, diphosphatidylglycerol and unidentified lipids. The DNA G+C content was 40·3 mol%. Phylogenetic trees based on 16S rRNA gene sequences exhibited that strain SW-152T forms a distinct evolutionary lineage within the Cytophaga–Flavobacterium–Bacteroides (CFB) group. Strain SW-152T exhibited low 16S rRNA similarity levels of less than 89·4 % to members belonging to the CFB group. Phenotypic properties of strain SW-152T differentiate it from phylogenetically related taxa. On the basis of phenotypic and phylogenetic data, strain SW-152T (=KCTC 12312T=JCM 12600T) was classified in a novel genus and species, Marinicola seohaensis gen. nov., sp. nov.

Two Gram-negative, rod-shaped bacterial strains, MSS-160T and MSS-161, were isolated from a marine solar saltern in the Yellow Sea, Korea, and subjected to a polyphasic taxonomic study. The two strains grew optimally in the presence of 2 % (w/v) NaCl and at 25–30 °C. Strains MSS-160T and MSS-161 contained MK-7 as the predominant menaquinone and large amounts of fatty acids C16 : 1 ω7c and/or iso-C15 : 0 2-OH and iso-C15 : 0. The DNA G+C content of the two strains was 41 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the two strains were phylogenetically affiliated to the genus Algoriphagus. Strains MSS-160T and MSS-161 exhibited no difference in their 16S rRNA gene sequences and possessed a mean DNA–DNA relatedness level of 91 %; they exhibited 16S rRNA similarity levels of 96·6–99·3 % to the type strains of Algoriphagus species with validly published names. DNA–DNA relatedness levels between the two strains and the type strains of five Algoriphagus species were lower than 46 %. On the basis of phenotypic, phylogenetic and genetic data, strains MSS-160T and MSS-161 were classified in the genus Algoriphagus as members of a novel species, for which the name Algoriphagus yeomjeoni sp. nov. (type strain, MSS-160T=KCTC 12309T=JCM 12598T) is proposed.

Highly diverse Bradyrhizobium strains nodulate genistoid legumes (brooms) in the Canary Islands, Morocco, Spain and the Americas. Phylogenetic analyses of ITS, atpD, glnII and recA sequences revealed that these isolates represent at least four distinct evolutionary lineages within the genus, namely Bradyrhizobium japonicum and three unnamed genospecies. DNA–DNA hybridization experiments confirmed that one of the latter represents a new taxonomic species for which the name Bradyrhizobium canariense is proposed. B. canariense populations experience homologous recombination at housekeeping loci, but are sexually isolated from sympatric B. japonicum bv. genistearum strains in soils of the Canary Islands. B. canariense strains are highly acid-tolerant, nodulate diverse legumes in the tribes Genisteae and Loteae, but not Glycine species, whereas acid-sensitive B. japonicum soybean isolates such as USDA 6T and USDA 110 do not nodulate genistoid legumes. Based on host-range experiments and phylogenetic analyses of symbiotic nifH and nodC sequences, the biovarieties genistearum and glycinearum for the genistoid legume and soybean isolates, respectively, were proposed. B. canariense bv. genistearum strains display an overlapped host range with B. japonicum bv. genistearum isolates, both sharing monophyletic nifH and nodC alleles, possibly due to the lateral transfer of a conjugative chromosomal symbiotic island across species. B. canariense is the sister species of B. japonicum, as inferred from a maximum-likelihood Bradyrhizobium species phylogeny estimated from congruent glnII+recA sequence partitions, which resolves eight species clades. In addition to the currently described species, this phylogeny uncovered the novel Bradyrhizobium genospecies alpha and beta and the photosynthetic strains as independent evolutionary lineages. The type strain for B. canariense is BTA-1T (=ATCC BAA-1002T=LMG 22265T=CFNE 1008T).

Two novel Psychrobacter-like bacterial strains, JG-219T and JG-220, were isolated from jeotgal, a traditional Korean fermented seafood. Cells of strains JG-219T and JG-220 were Gram-negative, non-motile coccobacilli. Growth of the two strains was observed at 4–32 °C. They grew optimally in the presence of 2–5 % (w/v) NaCl. Strains JG-219T and JG-220 contained C18 : 1 ω9c and C17 : 1 ω8c as the major fatty acids and Q-8 as the predominant ubiquinone. The DNA G+C contents of strains JG-219T and JG-220 were 43·5 and 43·0 mol%, respectively. The two strains showed no difference in their 16S rRNA gene sequences but exhibited minor differences in their phenotypic properties. Strains JG-219T and JG-220 exhibited levels of 16S rRNA gene sequence similarity of 95·2–98·7 % to the type strains of recognized Psychrobacter species. The mean level of DNA–DNA relatedness between strains JG-219T and JG-220 was 84·4 %. The two strains exhibited levels of DNA–DNA relatedness of 1·5–32·9 % to the type strains of eight phylogenetically related Psychrobacter species. On the basis of phenotypic data and phylogenetic and genetic distinctiveness, the two strains were classified as representing a novel species within the genus Psychrobacter, Psychrobacter cibarius sp. nov. The type strain is JG-219T (=KCTC 12256T=DSM 16327T).

A polychlorophenol-degrading strain, designated MT1T, and three MT1-like strains, MT101, MT103 and MT104, were isolated from a cold (4–8 °C) fluidized-bed process treating chlorophenol-contaminated groundwater in southern Finland. The organisms were Gram-negative, rod-shaped, catalase-positive, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains belonged to the α-4 subclass of the Proteobacteria and were members of the genus Novosphingobium. The highest 16S rRNA gene sequence similarity observed for these strains was 96·5 % with the type strains of Novosphingobium hassiacum, Novosphingobium aromaticivorans and Novosphingobium subterraneum. Chemotaxonomic data (major ubiquinone: Q-10; major polyamine: spermidine; major polar lipids: phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and sphingoglycolipid; major fatty acids: 18 : 1ω7c, 16 : 1ω7c and 2-OH 14 : 0) as well as the ability to reduce nitrate supported the affiliation of the strains to the genus Novosphingobium. Based on the phylogenetic analysis, whole-cell fatty acid composition as well as biochemical and physiological characteristics, the MT1-like strains were highly similar and could be separated from all recognized Novosphingobium species. The novel species Novosphingobium lentum sp. nov. is proposed to accommodate strains MT1T (=DSM 13663T=CCUG 45847T), MT101 (=CCUG 45849), MT103 (=CCUG 45850) and MT104 (=CCUG 45851).

A novel mesophilic, hydrogen-oxidizing, sulfur-reducing bacterium, designated strain BKB25Ts-YT, was isolated from hydrothermal sediments at Iheya North in the Mid-Okinawa Trough, Japan. Cells were Gram-negative, motile rods (1·8–2·1 μm long and 0·5–0·7 μm wide). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Elemental sulfur and nitrate served as electron acceptors, respectively yielding hydrogen sulfide and ammonium. Growth was observed at 20–42 °C (optimum 32 °C; 3 h doubling time), pH 5·0–6·5 (optimum 6·0) and in the presence of 2·0–4·0 % NaCl (optimum 2·5 %) via respiratory S0 reduction with H2. The G+C content of the genomic DNA was 37·2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate represented the first strain for which taxonomic properties have been characterized within the previously uncultivated ε-Proteobacteria Group G. On the basis of the physiological and molecular properties of the novel isolate, the genus name Thioreductor gen. nov. is proposed, with Thioreductor micantisoli sp. nov. as the type species. The type strain is BKB25Ts-YT (=JCM 12457T=DSM 16661T).

A Gram-negative, motile, rod-shaped bacterium, designated strain P1T, was isolated from activated sludge of a municipal wastewater treatment plant. Phylogenetic analysis of its 16S rRNA gene sequence placed the novel isolate among representatives of the family Comamonadaceae. The closest relatives in reconstructed phylogenetic trees were Pseudomonas spinosa, Macromonas bipunctata and Hydrogenophaga species. Strain P1T was not able to grow anaerobically or autotrophically, reduced nitrate to nitrite and required vitamins for growth. Ubiquinone 8 (Q8) and 3-hydroxy-substituted fatty acids were present, but 2-hydroxy fatty acids were absent. The G+C content of the DNA was 67 mol%. Phenotypic characteristics allowed a clear differentiation of strain P1T from representatives of the genera Hydrogenophaga and Macromonas, whereas DNA–DNA hybridization experiments revealed that strain P1T did not belong to the species P. spinosa. As a peculiarity, cells of strain P1T and P. spinosa ATCC 14606T were able to accumulate large amounts of polyhydroxyalkanoates and polyphosphate in the form of large intracellular granules. Apparently in both strains nitrogen limitation stimulates the production of polyhydroxyalkanoates, whereas carbon starvation induces the formation of polyphosphates. Based upon phylogenetic and phenotypic evidence, it is proposed to establish the novel taxon Malikia granosa gen. nov., sp. nov., represented by the type strain P1T (=DSM 15619T=JCM 12706T=CIP 108194T). The most closely related species of strain P1T was P. spinosa. This species has been misclassified, and it is proposed to transfer it to the new genus Malikia as Malikia spinosa gen. nov., comb. nov. The type strain is ATCC 14606T (=DSM 15801T).

A Gram-negative, slightly halophilic, non-pigmented, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water off the Spanish coast near Valencia. This strain was poorly reactive, being unable to grow in most carbon sources analysed in minimal medium. However, good growth was observed when more complex media and longer incubation times were used. Phylogenetic analysis based on an almost complete 16S rRNA gene sequence placed strain 2SM4T within the Roseobacter group, in the vicinity of uncultured bacteria described as gall symbionts of several species of the red alga Prionitis. Sequence similarity values between strain 2SM4T and the closest neighbouring species were below 95·0 %. The cellular fatty acid composition of the Mediterranean strain confirmed its position within the ‘Alphaproteobacteria’, sharing 18 : 1ω7c as the major cellular fatty acid. The phylogenetic distance from any taxon with a validly published name and also a number of distinguishing features support the designation of strain 2SM4T as representing a novel genus and species, for which the name Nereida ignava gen. nov., sp. nov. is proposed. The type strain is 2SM4T (=CECT 5292T=DSM 16309T=CIP 108404T=CCUG 49433T).

Five strains of an unusual Gram-negative, catalase-positive, oxidase-positive, coccobacillus-shaped bacterium isolated from the lungs and heart of pigs with pneumonia and pericarditis were characterized by phenotypic and molecular genetic methods. On the basis of cellular morphology and biochemical criteria, the isolates were tentatively assigned to the family Neisseriaceae, although they did not appear to correspond to any recognized genus or species. Comparative 16S rRNA gene sequencing showed that the five unidentified strains were phylogenetically highly related to each other and represent a hitherto unknown subline within the family Neisseriaceae. On the basis of both phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from pigs be classified as a novel genus and species within the family Neisseriaceae, for which the name Uruburuella suis gen. nov., sp. nov. is proposed. The type strain of U. suis is 1258/02T (=CCUG 47806T=CECT 5685T).

A Gram-negative, slightly halophilic, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water near Valencia (Spain). Comparison of the almost complete 16S rRNA gene sequence showed that strain 4SM3T belonged to the Roseobacter group, with Jannaschia helgolandensis as its closest relative, with a similarity of 98·7 %. DNA–DNA hybridization analysis showed that the Mediterranean isolate had a level of relatedness of less than 42 % with J. helgolandensis and therefore that it represented a novel species of the genus Jannaschia. Phenotypic characteristics gave further evidence that the two organisms are not related at the species level. Isolate 4SM3T grows on solid media as irregular pink–red colonies that penetrate into the agar. Cells are rods, motile by a tuft of polar flagella. The DNA base composition is 64·6 mol% G+C. Morphological, physiological and genotypic differences from related species support the description of a novel species, Jannaschia rubra sp. nov., with strain 4SM3T (=CECT 5088T=DSM 16279T) as the type strain.