- Volume 56, Issue 7, 2006

A buff-yellow-pigmented bacterium, strain K22-20T, which was isolated from a cold desert of the Indian Himalayas, was subjected to a polyphasic taxonomic study. Phenotypic and chemical properties of strain K22-20T were consistent with its classification in the genus Ornithinimicrobium. The major fatty acids of the strain were iso-C17 : 1 ω9c (cis-15-methyl 7-hexadecenoic acid), iso-C15 : 0 (13-methyl tetradecanoic acid), iso-C16 : 0 (14-methyl pentadecanoic acid) and iso-C17 : 0 (15-methyl hexadecanoic acid). The G+C content of the genomic DNA was 71 mol%. According to 16S rRNA gene sequence analysis, strain K22-20T was closely related to Ornithinimicrobium humiphilum HKI 0124T (97.7 %). However, genomic relatedness between strain K22-20T and O. humiphilum MTCC 6406T, as revealed by DNA–DNA hybridization, was 64.5 %. Based on the polyphasic data, strain K22-20T (=MTCC 6545T=DSM 17687T=JCM 12763T) represents a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium kibberense sp. nov. is proposed.

A coral-red-pigmented actinobacterium, strain K30-10T, was isolated from a soil sample from a cold desert of the Indian Himalayas. Chemical and phenotypic properties of strain K30-10T were consistent with its classification in the genus Dietzia. It showed 97.9 % 16S rRNA gene sequence similarity to Dietzia maris MTCC 7011T; similarities to the type strains of three other species of the genus, Dietzia natronolimnaea, Dietzia psychralcaliphila and Dietzia cinnamea, were 94.4–96.0 %. The DNA–DNA relatedness between K30-10T and the closely related strain D. maris MTCC 7011T was 59.2 %. The DNA G+C content of strain K30-10T was 67.0 mol%. Based on physiological and biochemical tests and genotypic differences between strain K30-10T and its closest phylogenetic relatives, it is proposed that this strain represents a novel species, Dietzia kunjamensis sp. nov.; the type strain is K30-10T (=MTCC 7007T=DSM 44907T=JCM 13325T).

An extremely halophilic archaeon (strain 7-3T) was isolated from Aibi salt lake in Xin-Jiang, China. It formed small (<1.0 mm), red, elevated colonies on salt-milk agar medium. Strain 7-3T was able to grow at pH 6.5–9.5 (optimum pH 8.0) and at 20–50 °C (optimum 45 °C). Analysis of its 16S rRNA gene sequence indicated that strain 7-3T was phylogenetically related to members of the genus Natronorubrum, with sequence similarities of 97.0 % to Natronorubrum bangense A33T and 95.2 % to Natronorubrum tibetense GA33T. The G+C content of its DNA was 61.2 mol% (T m). Levels of DNA–DNA relatedness to Nrr. bangense and Nrr. tibetense were 45 and 37 %, respectively. It is concluded that strain 7-3T (=CGMCC 1.4299T=JCM 13488T) should be classified as the type strain of a novel species of the genus Natronorubrum, for which the name Natronorubrum aibiense sp. nov. is proposed. Based on the properties of Nrr. aibiense given here and of those of Nrr. bangense and Nrr. tibetense described previously, an emended description of the genus Natronorubrum is presented.

Strain XH-48T was isolated from the sediment of Lake Xilinhot, a saline lake in Inner Mongolia (China). The organism is pleomorphic, neutrophilic and requires at least 2.5 M (15 %) NaCl, but not MgCl2, for growth; it exhibits optimal growth at 3.4 M (20 %) NaCl. The G+C content of its DNA is 61 mol%. 16S rRNA gene sequence analysis revealed that strain XH-48T is a member of the family Halobacteriaceae, but there were low levels of similarity with other members of this family. The highest sequence similarity values (94.5 and 93.3 %) were obtained with the 16S rRNA genes of Natrialba aegyptiaca and Natrialba asiatica, respectively. Polar lipid analyses revealed that strain XH-48T contains phosphatidylglycerol and phosphatidylglyceromethylphosphate, derived from both C20C20 and C20C25 glycerol diethers, and two unidentified glycolipids. On the basis of the data obtained, the novel isolate cannot be classified within any recognized genus. Strain XH-48T should be placed within a novel genus and species within the family Halobacteriaceae, order Halobacteriales, for which the name Halostagnicola larsenii gen. nov., sp. nov. is proposed. The type strain of Halostagnicola larsenii is strain XH-48T (=DSM 17691T=CGMCC 1.5338T=JCM 13463T=CECT 7116T).

Three strains of CO2-reducing methanogens were isolated from marine sediments. Strain PL-15/HP was isolated from marine sediments of the Lipari Islands, near Sicily and the other two strains, Nankai-2 and Nankai-3T, were isolated from deep marine sediments of the Nankai Trough, about 50 km from the coast of Japan. Analysis of the cellular proteins and 16S rRNA gene sequences indicated that these three strains represented a single novel species that formed a deep branch of the mesophilic methanococci. Phylogenetic analysis indicated that the three strains were most closely related to Methanothermococcus okinawensis (95 % 16S rRNA gene sequence similarity). However, strains PL-15/HP, Nankai-2 and Nankai-3T grew at temperatures that were more similar to those of recognized species within the genus Methanococcus. Strain Nankai-3T grew fastest at 46 °C. Results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strains PL-15/HP, Nankai-2 and Nankai-3T from closely related species. The name Methanococcus aeolicus sp. nov. is proposed, with strain Nankai-3T (=OCM 812T=DSM 17508T) as the type strain.

A novel extremely halophilic archaeon was isolated from Ezzemoul sabkha, Algeria. The strain, designated 5.1T, was neutrophilic, motile and Gram-negative. At least 15 % (w/v) NaCl was required for growth. The isolate grew at pH 6.5–9.0, with optimum growth at pH 7.0–7.5. Mg2+ was required for growth. Polar lipids were C20C20 derivatives of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester, and phosphatidylglycerol sulfate and sulfated diglycosyl diether. The genomic DNA G+C content of strain 5.1T was 61.9 mol% (T m). Phylogenetic analysis based on comparison of 16S rRNA gene sequences revealed that strain 5.1T clustered with Halorubrum species. The results of DNA–DNA hybridization and biochemical tests allowed genotypic and phenotypic differentiation of strain 5.1T from other Halorubrum species. The name Halorubrum ezzemoulense sp. nov. (type strain 5.1T=CECT 7099T=DSM 17463T) is proposed.

Two extremely halophilic archaea, strains 9-3T and 31-hongT, were isolated from Aibi salt lake and Aiding salt lake in Xin-Jiang, China. Their morphology, physiology, biochemical features, polar lipid compositions and 16S rRNA gene sequences were characterized in order to elucidate their taxonomic status. The results from this study indicated that strains 9-3T and 31-hongT are members of the genus Halorubrum. Their physiological properties and polar lipid compositions are clearly different from those of the currently described species of Halorubrum. DNA–DNA relatedness values for strain 9-3T with respect to its closely related neighbours Halorubrum saccharovorum JCM 8865T and Halorubrum lacusprofundi JCM 8891T were 51.6 and 25.1 %, respectively, DNA–DNA relatedness values for strain 31-hongT with respect to its closely related neighbours Hrr. saccharovorum JCM 8865T and Hrr. lacusprofundi JCM 8891T were 29.4 and 44.9 %, respectively, and DNA–DNA relatedness between strains 9-3T and 31-hongT was 54 %. Thus, two novel species of the genus Halorubrum are proposed, Halorubrum lipolyticum sp. nov. (type strain 9-3T=CGMCC 1.5332T=JCM 13559T) and Halorubrum aidingense sp. nov. (type strain 31-hongT=CGMCC 1.2670T=JCM 13560T).

Bacteria in the family Flavobacteriaceae are increasingly recognized to play important roles in the degradation of organic matter during and following algal blooms. A novel heterotrophic, rod-shaped, aerobic, yellow-pigmented and gliding bacterium was isolated from a seawater sample collected in the Bay of Blanes in the north-western Mediterranean Sea. Analysis of its 16S rRNA gene sequence, retrieved from the whole-genome sequence, showed that the bacterium was closely related to members of the genus Leeuwenhoekiella within the family Flavobacteriaceae, phylum Bacteroidetes. Phenotypic, genotypic, chemotaxonomic and phylogenetic analyses supported the creation of a novel species to accommodate this bacterium, for which the name Leeuwenhoekiella blandensis sp. nov. is proposed. The type strain is MED 217T (=CECT 7118T=CCUG 51940T).

A taxonomic study was performed on strain R2A10-2T, isolated from greenhouse soil cultivated with lettuce (Lactuca sativa L.), collected in Wanju Province, Korea. The bacterial cells were Gram-negative, aerobic, short rods. The growth temperature and pH were 5–35 °C and 5.0–9.0, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this isolate had 93.3–97.7 % similarity to Chryseobacterium species: the highest sequence similarities were to the type strains of Chryseobacterium daecheongense (97.7 %), Chryseobacterium formosense (97.1 %) and Chryseobacterium defluvii (96.9 %). Low levels of DNA–DNA relatedness were found between strain R2A10-2T and the type strains of these three species (<28 %). Differences in phenotypic properties were found with respect to Chryseobacterium species with validly published names. The predominant cellular fatty acids were iso-15 : 0 (40.0 %), iso-17 : 0 3-OH (21.9 %), iso-17 : 1ω9c (11.7 %) and summed feature 4 (iso-15 : 0 2-OH and/or 16 : 1ω7c/t, 11.0 %). Menaquinone MK-6 was detected as the sole respiratory quinone. The G+C content of the genomic DNA was 37.8 mol%. On the basis of the genomic and phenotypic evidence, this isolate represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium wanjuense sp. nov. is proposed. The type strain is R2A10-2T (=KACC 11468T=DSM 17724T).

A novel Tenacibaculum-like bacterial strain, SMK-4T, was isolated from a tidal flat sediment in Korea. Strain SMK-4T was Gram-negative, pale yellow-pigmented and rod-shaped. It grew optimally at 30–37 °C and in the presence of 2–3 % (w/v) NaCl. It contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C16 : 0 3-OH and C16 : 1 ω7c and/or iso-C15 : 0 2-OH as the major fatty acids (>10 % of total fatty acids). The DNA G+C content was 33.6 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain SMK-4T fell within the evolutionary radiation encompassed by the genus Tenacibaculum. Strain SMK-4T exhibited 16S rRNA gene sequence similarity levels of 95.2–98.6 % with respect to the type strains of recognized Tenacibaculum species. DNA–DNA relatedness levels and differential phenotypic properties made it possible to categorize strain SMK-4T as a species that is separate from previously described Tenacibaculum species. On the basis of phenotypic properties and phylogenetic and genetic distinctiveness, strain SMK-4T (=KCTC 12569T=JCM 13491T) should be classified as a novel Tenacibaculum species, for which the name Tenacibaculum aestuarii sp. nov. is proposed.

Strain VP48T was isolated from drinking water during a screening programme to monitor the bacterial population present in the water distribution system of Sevilla (Spain). A polyphasic taxonomic study of the isolate resulted in its identification as a member of the genus Chryseobacterium, members of which are widely distributed in soil, water and clinical sources. However, the 16S rRNA gene sequence similarity values of strain VP48T to the type strains of Chryseobacterium species were 96 % or lower. Furthermore, phenotypic characteristics clearly indicated that the isolate represents a novel Chryseobacterium species, for which the name Chryseobacterium hispanicum sp. nov. is proposed; strain VP48T (=CECT 7129T=CCM 7359T=JCM 13554T) is the type strain. The DNA G+C content of this strain is 34.3 mol%.

The characteristics of three Bacteroides species, Bacteroides distasonis, Bacteroides goldsteinii and Bacteroides merdae, were examined. 16S rRNA gene sequence analysis showed that B. distasonis, B. goldsteinii and B. merdae should not be classified as species within the genus Bacteroides. Although B. distasonis, B. goldsteinii and B. merdae were phylogenetically related to Tannerella forsythensis, the ratios of anteiso-C15 : 0 to iso-C15 : 0 in whole-cell methanolysates of the three species were different from that of T. forsythensis. In addition, whereas the major menaquinones of T. forsythensis were MK-10 and MK-11, the major menaquinones of B. distasonis, B. goldsteinii and B. merdae were MK-9 and MK-10. The three species were phenotypically similar to Bacteroides sensu stricto, but phylogenetically distinct. Furthermore, B. distasonis, B. goldsteinii and B. merdae could be differentiated from Bacteroides sensu stricto (predominant menaquinones: MK-10 and MK-11) by the menaquinone composition. This is an important chemotaxonomic characteristic of the three species. On the basis of these data, a novel genus, Parabacteroides gen. nov., is proposed for B. distasonis, B. goldsteinii and B. merdae, with three species, Parabacteroides distasonis gen. nov., comb. nov. (the type species), Parabacteroides goldsteinii comb. nov. and Parabacteroides merdae comb. nov. The type strains of P. distasonis, P. goldsteinii and P. merdae are JCM 5825T (=CCUG 4941T=DSM 20701T=ATCC 8503T), JCM 13446T (=CCUG 48944T) and JCM 9497T (=CCUG 38734T=ATCC 43184T), respectively.

A marine bacterium, designated strain KMM 6038T, was subjected to taxonomic analysis via a polyphasic approach. Cells of the strain were heterotrophic, orange-pigmented, Gram-negative and motile by means of gliding. 16S rRNA gene sequence analysis indicated that strain KMM 6038T was closely related to the type species of the genera Algibacter and Yeosuana, members of the family Flavobacteriaceae, with sequence similarities of 93.8 and 93.6 % to the respective type strains. However, several chemotaxonomic and phenotypic characteristics, such as the cellular fatty acid profile (iso-C15 : 0, anteiso-C15 : 0, iso-C15 : 1, C15 : 0, C15 : 1 ω6c, iso-C15 : 0 3-OH and iso-C17 : 0 3-OH) and the low G+C content of the DNA (35.7 mol%), indicated that the strain should be separated from these two genera. From the results of phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, the bacterium should be classified as representing a novel genus and species, for which the name Mariniflexile gromovii gen. nov., sp. nov. is proposed. The type strain of Mariniflexile gromovii is KMM 6038T (=KCTC 12570T=LMG 22578T).

Two Gram-negative, anaerobic, non-spore-forming rod-shaped organisms were isolated from human faeces. These isolates were tentatively identified as Bacteroides based on morphological and biochemical criteria and appeared closely related to Bacteroides vulgatus ATCC 8482T. The 16S rRNA gene sequence analysis showed that the isolates were highly related to each other (99.5 %) and confirmed their placement in the genus Bacteroides. 16S rRNA gene sequence similarity values with close phylogenetic neighbours Bacteroides vulgatus ATCC 8482T (96 %) and Bacteroides massiliensis CCUG 48901T (93 %) preliminarily demonstrated that the organisms represented a novel species. The results of phenotypic, chemotaxonomic and 16S rRNA gene sequence analyses, and DNA–DNA homology values provided evidence that these two unknown isolates represent a single species and should be assigned to a novel species of the genus Bacteroides, as Bacteroides dorei sp. nov. The type strain is JCM 13471T (=DSM 17855T).

Two yellow-pigmented, Gram-negative, rod-shaped bacterial strains, GH1-10T and GH29-5T, were isolated from greenhouse soils in Korea. 16S rRNA gene sequence analysis indicated that these strains were related to members of the genus Flavobacterium. Strain GH1-10T was most closely related to Flavobacterium psychrolimnae and Flavobacterium denitrificans, with sequence similarities of 95.9 and 95.2 %, respectively. Strain GH29-5T was most closely related to ‘Flavobacterium saliodium’, F. denitrificans and Flavobacterium frigoris, with sequence similarities of 94.3, 92.5 and 92.5 %, respectively. The major cellular fatty acids of GH1-10T were iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c) and iso-C17 : 0 3-OH, and those of GH29-5T were iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0 3-OH. Both strains contained menaquinone with six isoprene units (MK-6) as the sole quinone. The DNA G+C contents of GH1-10T and GH29-5T were 35 and 39 mol%, respectively. Based on the phylogenetic and phenotypic data presented, it is concluded that the two bacteria represent two separate novel species of the genus Flavobacterium. The names proposed to accommodate these organisms are Flavobacterium daejeonense sp. nov., with type strain GH1-10T (=KACC 11422T=DSM 17708T), and Flavobacterium suncheonense sp. nov., with type strain GH29-5T (=KACC 11423T=DSM 17707T).

Bacteria-like endosymbionts of females of the plant-parasitic nematodes Globodera rostochiensis and Heterodera goettingiana and juveniles of Heterodera glycines were first observed during transmission electron microscopy (TEM) studies conducted in the 1970s. These organisms were characterized as being rod-shaped, ranging in size from 0.3 to 0.5 μm in diameter and 1.8 to 3 μm in length and containing structures labelled as striated inclusion bodies or tubular structures. A population of H. glycines was obtained from the soybean field where infected nematodes were first discovered in order to conduct TEM studies of females and males and to determine the phylogenetic position of the H. glycines endosymbiont among bacteria by studying the 16S rRNA and gyrB gene sequences. The bacterium was observed in the pseudocoelom and intestine of juveniles, females and males, in hypodermal chords of juveniles and males, in ovary walls and in oocytes and spermatozoa. The bacterium was polymorphic, measuring 0.4–0.8×2.5–4.5 μm, and many specimens contained an array of microfilament-like structures similar to those observed in ‘Candidatus Cardinium hertigii’, the endosymbiont of Encarsia spp. wasps. Phylogenetic analysis of the 16S rRNA and gyrB genes of the H. glycines-infecting bacterium revealed 93 % and 81 % sequence identity, respectively, to the homologous genes in ‘Candidatus C. hertigii’. Thus, the name ‘Candidatus Paenicardinium endonii’ is proposed for the bacterial endosymbiont of the plant-parasitic nematode H. glycines.