- Volume 56, Issue 12, 2006

A Gram-positive, non-motile, rod- or coccoid-shaped Isoptericola-like bacterium, strain DS-3T, was isolated from a soil sample from Dokdo, Korea, and its taxonomic position was investigated by a polyphasic approach. The organism grew optimally at 30 °C and pH 7.0–8.0. Strain DS-3T had the peptidoglycan type based on l-lys–d-Asp, and galactose, glucose, rhamnose and ribose as the whole-cell sugars. It contained MK-9(H4) as the predominant menaquinone and anteiso-C15 : 0 and iso-C15 : 0 as the major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unidentified glycolipids. The DNA G+C content was 74.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-3T was most closely related to members of the genus Isoptericola. Similarity values between the 16S rRNA gene sequences of strain DS-3T and the type strains of Isoptericola species ranged from 98.0 to 98.4 %. DNA–DNA relatedness values (11–23 %) and differential phenotypic properties demonstrated that strain DS-3T was distinguishable from recognized Isoptericola species. On the basis of phenotypic properties and phylogenetic and genetic distinctiveness, strain DS-3T represents a novel species in the genus Isoptericola, for which the name Isoptericola dokdonensis sp. nov. is proposed. The type strain is DS-3T (=KCTC 19128T=CIP 108921T).

A Gram-negative bacterium, designated strain EMB111T, was isolated from activated sludge performing enhanced biological phosphorus removal in a sequencing batch reactor. Cells were long and rod-shaped. The isolate was strictly aerobic and non-motile. The strain grew optimally at 25–30 °C and pH 7.5–8.0. The predominant fatty acids of strain EMB111T were iso-C15 : 0, C16 : 1 ω5c, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH, C16 : 0 3-OH, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH). The strain contained a large amount of phosphatidylglycerol and small amounts of two unknown phospholipids (PL1, PL2) as the polar lipids. The major isoprenoid quinone was menaquinone-7. The G+C content of the genomic DNA was 42.7 mol%. Phylogenetic analysis showed that strain EMB111T formed a phyletic cluster with members of the genus Runella within the family Flexibacteraceae and was most closely related to Runella slithyformis ATCC 29530T with a 16S rRNA gene sequence similarity of 94.8 %. On the basis of chemotaxonomic data and molecular properties, strain EMB111T represents a novel species within the genus Runella, for which the name Runella limosa sp. nov. is proposed. The type strain is EMB111T (=KCTC 12615T=DSM 17973T).

Four aerobic, heterotrophic, yellow-pigmented and flexirubin-producing bacterial strains with gliding motility were isolated from acidic Sphagnum-dominated wetlands of Northern Russia. These bacteria are capable of degrading xylan, laminarin and some other polysaccharides, but not cellulose, pectin or chitin. The four strains possess almost identical 16S rRNA gene sequences and are most closely related (98.9–99.5 % sequence similarity) to the recently reclassified species of the phylum Bacteroidetes, Chitinophaga arvensicola Kämpfer et al. 2006 , formerly known as [Cytophaga] arvensicola Oyaizu et al. 1983 . However, the novel isolates from Sphagnum peat differed from C. arvensicola DSM 3695T in their ability to degrade xylan and starch, by greater tolerance of acidic pH and by their inability to reduce nitrate. An emended description of this species is proposed.

Three Gram-negative, non-spore-forming strains were isolated from sediment from the South China Sea, China, and their taxonomic positions were investigated using a polyphasic approach. Strains HN-171T, HN-172 and HN-181 grew optimally at 30 °C, in the presence of 4.5–5.0 NaCl % (w/v) and at pH 7.2–7.4. They contained MK-6 as the predominant respiratory quinone and contained iso-C15 : 1 G, iso-C15 : 0, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c/t) and C15 : 0 as the major fatty acids. The DNA G+C content of strain HN-171T was 34.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences demonstrated that strain HN-171T, together with strains HN-172 and HN-181, formed a distinct evolutionary lineage within the family Flavobacteriaceae. The 16S rRNA gene sequences of strains HN-171T, HN-172 and HN-181 shared 99.8–100 % similarity with each other, and the sequence of strain HN-171T exhibited similarity values below 90.2 % with those of other members of the family Flavobacteriaceae. The closest relative of HN-171T was Coenonia anatina LMG 14382T (90.2 %). On the basis of their phenotypic and phylogenetic properties, the three isolates represent a novel genus and a novel species, for which the name Zhouia amylolytica gen. nov., sp. nov. is proposed. The type strain is HN-171T (=CGMCC 1.6114T=JCM 14016T).

Eight bacterial strains isolated from the caecum of chicken, BL2T, BL66, EG3, EG6, M27, BL78T, C35T and C43, were characterized by determining their phenotypic characteristics, cellular fatty acid profiles, menaquinone profiles and phylogenetic positions based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that these isolates belonged to the genus Bacteroides. One group of five strains (BL2T, BL66, EG3, EG6 and M27) was related most closely to Bacteroides coprocola JCM 12979T, with approximately 93 % 16S rRNA gene sequence similarity, and to Bacteroides plebeius JCM 12973T, with about 92 % similarity, and shared ⩾99.6 % similarity with each other. Strain BL78T exhibited 90.5 % similarity to B. plebeius JCM 12973T and 89.8 % similarity to B. coprocola JCM 12979T and differed from the above group of five strains at ⩾10 % sequence divergence. Strains C35T and C43 were related most closely to Bacteroides eggerthii JCM 12986T, with 95.1 % sequence similarity, to Bacteroides stercoris JCM 9496T, with 94.6 % similarity, and to Bacteroides uniformis JCM 5828T, with 94.4 % similarity, and shared 100 % similarity with each other. From results of phenotypic examination, cellular fatty acid composition analysis, menaquinone composition analysis and DNA G+C contents, the group of five strains as well as strain BL78T were shown to differ from the type strains of B. coprocola and B. plebeius. Strain BL78T differed from the others based on its menaquinone composition, which included MK-11 and MK-12. Strains C35T and C43 could also be differentiated from the type strains of B. eggerthii, B. stercoris and B. uniformis. The group of five strains, strain BL78T, B. coprocola JCM 12979T and B. plebeius JCM 12973T showed low levels of DNA–DNA relatedness (<35 %) with each other. High levels of DNA–DNA relatedness were obtained within the group of five strains (>75 %). Strains C35T and C43 exhibited a high level of DNA–DNA relatedness (>88 %) with each other, but low levels with B. eggerthii JCM 12986T (<40 %), B. stercoris JCM 9496T (<37 %) and B. uniformis JCM 5828T (<16 %). On the basis of these data, three novel Bacteroides species are proposed: Bacteroides barnesiae sp. nov. (type strain BL2T=JCM 13652T=DSM 18169T), Bacteroides salanitronis sp. nov. (type strain BL78T=JCM 13657T=DSM 18170T) and Bacteroides gallinarum sp. nov. (type strain C35T=JCM 13658T=DSM 18171T).

A novel alkaliphilic and psychrophilic bacterium was isolated from the cold and alkaline ikaite tufa columns of the Ikka Fjord in south-west Greenland. According to 16S rRNA gene sequence analysis, strain GCM71T belonged to the family ‘Flexibacteraceae’ in the phylum Bacteroidetes. Strain GCM71T, together with five related isolates from ikaite columns, formed a separate cluster with 86–93 % gene sequence similarity to their closest relative, Belliella baltica. The G+C content of the DNA from strain GCM71T was 43.1 mol%, whereas that of B. baltica was reported to be 35 mol%. DNA–DNA hybridization between strain GCM71T and B. baltica was 9.5 %. The strain was red pigmented, Gram-negative, strictly aerobic with non-motile, rod-shaped cells. The optimal growth conditions for strain GCM71T were pH 9.2–10.0, 5 °C and 0.6 % NaCl. The fatty acid profile of the novel strain was dominated by branched and unsaturated fatty acids (90–97 %), with a high abundance of iso-C17 : 1 ω9c (17.5 %), iso-C17 : 0 3-OH (17.5 %) and summed feature 3, comprising iso-C15 : 0 2-OH and/or C16 : 1 ω7c (12.6 %). Phylogenetic, chemotaxonomic and physiological characteristics showed that the novel strain could not be affiliated to any known genus. A new genus, Rhodonellum gen. nov., is proposed to accommodate the novel strain. Strain GCM71T (=DSM 17998T=LMG 23454T) is proposed as the type strain of the type species, Rhodonellum psychrophilum sp. nov.

A novel psychrophilic, yellow-pigmented and obligate aerobic bacterium, strain 0499T, was isolated from the China No.1 glacier. Strain 0499T displayed the common phenotypic and chemotaxonomic features of the genus Flavobacterium, containing menaquinone-6 (MK-6) as the major quinone and C15 : 0, iso-C15 : 0, C17 : 1 ω6c and summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH) as the major fatty acids. Optimal growth occurred at 21 °C. The genomic DNA G+C content was 36.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain 0499T was related to members of the genus Flavobacterium, sharing the highest sequence similarities with Flavobacterium succinicans (97.9 %), Flavobacterium granuli (97.4 %) and Flavobacterium hydatis (97.2 %). On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, a novel species Flavobacterium glaciei is proposed with strain 0499T (=CGMCC 1.5380T=JCM 13953T) as the type strain.

The marine bacterial strain HY9T was isolated from sediment from the South China Sea. Strain HY9T is aerobic, heterotrophic and rose-pigmented. The cells are non-motile and curved, i.e. ring-like or horseshoe-shaped. The 16S rRNA gene sequence of strain HY9T was determined and blast searches revealed that it possessed significant sequence similarities with respect to Cyclobacterium species (92.8–93.6 %). Phylogenetic analysis confirmed that strain HY9T was tightly clustered with members of the genus Cyclobacterium. The cellular morphology and chemotaxonomic and phenotypic properties of strain HY9T showed that it should be classified as a member of the genus Cyclobacterium. Significant evolutionary distances and a range of phenotypic features distinguished strain HY9T from previously described Cyclobacterium species. Hence, strain HY9T represents a novel species in the genus Cyclobacterium, for which the name Cyclobacterium lianum sp. nov. is proposed. The type strain is HY9T (=CGMCC 1.6102T=JCM 14011T). On the basis of this study and previously described properties of Cyclobacterium species, an emended description of the genus Cyclobacterium is proposed.

Three strains of gliding bacteria, 24T, 62 and 71, isolated from a marine sponge and algae from the southern coastline of Thailand, were studied using a polyphasic approach to clarify their taxonomic positions. A phylogenetic analysis based on 16S rRNA gene sequences showed that the three isolates formed a distinct lineage within the family ‘Saprospiraceae’ of the phylum Bacteroidetes and were related to members of the genus Saprospira. The G+C contents of the isolates were in the range 38–39 mol%. The major respiratory quinone was MK-7. The predominant cellular fatty acids were 20 : 4ω6c (arachidonic acid), 16 : 0 and iso-17 : 0. On the basis of morphological, physiological and chemotaxonomic characteristics, together with DNA–DNA hybridization data and 16S rRNA gene sequences, the isolates represent a novel species of a novel genus, for which the name Aureispira marina gen. nov., sp. nov. is proposed. The type strain of Aureispira marina is 24T (=IAM 15389T=TISTR 1719T).

Three thermophilic, anaerobic, strictly chemolithoautotrophic, sulphur- and/or thiosulphate-reducing bacteria, designated SL17T, SL19T and SL22T, were isolated from deep-sea hydrothermal samples collected at 13 °N (East Pacific Rise), Guaymas Basin (Gulf of California) and 23 °N (Mid-Atlantic Ridge), respectively. These strains differed in their morphology, temperature range and optimum for growth, energy substrates and 16S rRNA gene sequences. The G+C content of the genomic DNA was 41 mol% (SL22T), 42 mol% (SL17T) and 46 mol% (SL19T). Comparative analysis of phenotypic and phylogenetic traits indicated that strains SL17T and SL22T represented two novel species of the genus Desulfurobacterium and that strain SL19T should be considered as a novel species of the genus Thermovibrio. The names Desulfurobacterium pacificum sp. nov. (type strain SL17T=DSM 15522T=JCM 12127T), Desulfurobacterium atlanticum sp. nov. (type strain SL22T=DSM 15668T=JCM 12129T) and Thermovibrio guaymasensis sp. nov. (type strain SL19T=DSM 15521T=JCM 12128T) are proposed for these organisms. Furthermore, phylogenetic data based on 16S rRNA gene sequence analyses correlated with the significant phenotypic differences between members of the lineage encompassing the genera Desulfurobacterium, Thermovibrio and Balnearium and that of the families Aquificaceae and Hydrogenothermaceae. It is therefore proposed that this lineage represents a new family, Desulfurobacteriaceae fam. nov., within the order Aquificales.

Two novel sulfate-reducing bacteria, strains ALDCT and Lake, which were able to oxidize n-alkanes, were isolated from a naval oily wastewater-storage facility (VA, USA) and from oilfield production water (OK, USA), respectively. The type strain (ALDCT) had a narrow substrate specificity and could grow only with n-alkanes (from C6 to C12), pyruvate, butyrate, hexanoic acid and 4-methyloctanoic acid. Cells of strain ALDCT stained Gram-negative and were slightly curved, short rods with oval ends (2.5–3.0×1.0–1.4 μm), often occurring in pairs. Cells tended to form aggregates or large clusters and were non-motile and did not form endospores. Optimum growth occurred between 31 and 37 °C and at pH 6.5–7.2. NaCl was not required for growth, but salt concentrations up to 55 g l−1 could be tolerated. The DNA G+C content was 53.6 mol%. Phylogenetic analysis of the 16S rRNA genes revealed that strains ALDCT and Lake were closely related, but not identical (99.9 % similarity). The two strains were not closely related to other known alkane-degrading, sulfate-reducing bacteria or to other genera of the Deltaproteobacteria. Therefore, it is proposed that strain ALDCT (=JCM 13588T=ATCC BAA-1302T) represents the type strain of a novel species and genus, with the name Desulfoglaeba alkanexedens gen. nov., sp. nov.

The relatedness of Roseomonas fauriae and Azospirillum brasilense was investigated using phenotypic methods and DNA–DNA hybridization. Conventional biochemical tests did not differentiate between the two taxa. DNA–DNA hybridization experiments revealed high values for relatedness between the type strains of these species and suggest that these two taxa constitute a single species. Strains previously identified as R. fauriae should be reclassified as A. brasilense, with the name Roseomonas fauriae as a later heterotypic synonym of Azospirillum brasilense.

A moderately thermophilic bacterial strain designated wcf1T, isolated from a hot spring located in the Tainan area, southern Taiwan, was characterized using a polyphasic approach. The cells were Gram-negative, non-pigmented, rod-shaped, non-spore-forming and motile. Phylogenetic analysis using 16S rRNA gene sequences showed that the strain formed a monophyletic branch towards the periphery of the evolutionary radiation occupied by the genus Schlegelella; its only close neighbour was the type strain of Schlegelella thermodepolymerans, K14T (97.8 %). The isolate was clearly distinguishable from other strains using phylogenetic analysis, DNA–DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics. It was evident from the genotypic and phenotypic data that strain wcf1T represents a novel species in the genus Schlegelella, for which the name Schlegelella aquatica sp. nov. is proposed, with the type strain wcf1T (=BCRC 17557T=LMG 23380T).

A lemon-shaped marine bacterium, strain CL-SP20T, isolated from hypersaline water from a solar saltern in Korea, was characterized in terms of its physiological and biochemical features, its fatty acid profile and its phylogenetic position based on 16S rRNA gene sequences. Analysis of the 16S rRNA gene sequence revealed a clear affiliation with the Roseobacter lineage (91.0–96.3 % similarity) of the family Rhodobacteraceae. However, strain CL-SP20T did not form a robust clade with any species of the Roseobacter clade, forming a distinct subline. Strain CL-SP20T is non-motile and forms beige colonies on marine agar. The strain is able to grow with sea salts at concentrations in the range 1–10 %, with optimal growth between 5 and 6 %. It grows at temperatures in the range 15–40 °C and at pH 6–10. The strain cannot oxidize thiosulfate. The fatty acids are dominated by 18 : 1ω7c (54.3 %) and 19 : 0 cyclo ω8c (20.4 %). The DNA G+C content is 67.3 mol%. According to the physiological data, fatty acid composition and phylogenetic analysis of the 16S rRNA gene sequence, strain CL-SP20T represents a novel species in a novel genus of the family Rhodobacteraceae, for which the name Citreimonas salinaria gen. nov., sp. nov. is proposed. The type strain of Citreimonas salinaria is CL-SP20T (=KCCM 42116T=JCM 13036T).

We investigated the diversity of a collection of 76 Xenorhabdus strains, isolated from at least 27 species of Steinernema nematodes and collected in 32 countries, using three complementary approaches: 16S rRNA gene sequencing, molecular typing and phenotypic characterization. The 16S rRNA gene sequences of the Xenorhabdus strains were highly conserved (similarity coefficient >95 %), suggesting that the common ancestor of the genus probably emerged between 250 and 500 million years ago. Based on comparisons of the 16S rRNA gene sequences, we identified 13 groups and seven unique sequences. This classification was confirmed by analysis of molecular typing profiles of the strains, leading to the classification of new isolates into the Xenorhabdus species described previously and the description of ten novel Xenorhabdus species: Xenorhabdus cabanillasii sp. nov. (type strain USTX62T=CIP 109066T=DSM 17905T), Xenorhabdus doucetiae sp. nov. (type strain FRM16T=CIP 109074T=DSM 17909T), Xenorhabdus griffiniae sp. nov. (type strain ID10T=CIP 109073T=DSM 17911T), Xenorhabdus hominickii sp. nov. (type strain KE01T=CIP 109072T=DSM 17903T), Xenorhabdus koppenhoeferi sp. nov. (type strain USNJ01T=CIP 109199T=DSM 18168T), Xenorhabdus kozodoii sp. nov. (type strain SaVT=CIP 109068T=DSM 17907T), Xenorhabdus mauleonii sp. nov. (type strain VC01T=CIP 109075T=DSM 17908T), Xenorhabdus miraniensis sp. nov. (type strain Q1T=CIP 109069T=DSM 17902T), Xenorhabdus romanii sp. nov. (type strain PR06-AT=CIP 109070T=DSM 17910T) and Xenorhabdus stockiae sp. nov. (type strain TH01T=CIP 109067T=DSM 17904T). The Xenorhabdus strains studied here had very similar phenotypic patterns, but phenotypic features nonetheless differentiated the following species: X. bovienii, X. cabanillasii, X. hominickii, X. kozodoii, X. nematophila, X. poinarii and X. szentirmaii. Based on phenotypic analysis, we identified two major groups of strains. Phenotypic group GA comprised strains able to grow at temperatures of 35–42 °C, whereas phenotypic group GB comprised strains that grew at temperatures below 35 °C, suggesting that some Xenorhabdus species may be adapted to tropical or temperate regions and/or influenced by the growth and development temperature of their nematode host.

A novel obligate methylamine utilizer (strain JLW8T), isolated from Lake Washington sediment, was characterized taxonomically. The isolate was an aerobic, Gram-negative bacterium. Cells were rod-shaped and motile by means of a single flagellum. Reproduction was by binary fission and no resting bodies were formed. Growth was observed within a pH range of 5–8.5, with optimum growth at pH 7.5. It utilized methylamine as a single source of energy, carbon and nitrogen. Methylamine was oxidized via methylamine dehydrogenase and formaldehyde was assimilated via the ribulose monophosphate cycle. The cellular fatty acid profile was dominated by C16 : 0 ω7c and C16 : 0 and the major phospholipid was phosphatidylethanolamine. The DNA G+C content was 54 mol%. 16S rRNA gene sequence analysis indicated that the new isolate was closely related (97–98 % similarity) to a broad group of sequences from uncultured or uncharacterized Betaproteobacteria, but only distantly related (93–96 % similarity) to known methylotrophs of the family Methylophilaceae. Strain JLW8T (=ATCC BAA-1282T=DSM 17540T) is proposed as the type strain of a novel species in a new genus within the family Methylophilaceae, Methylotenera mobilis gen. nov., sp. nov.

A novel bacterial strain, designated 170T, was collected from high latitude Arctic locations (77° 30′ N to approximately 81° 12′ N), including the Canadian Basin and Greenland Sea. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain 170T was related to members of the genus Glaciecola and had the highest 16S rRNA gene sequence similarity to Glaciecola mesophila. Cells were Gram-negative, psychrophilic, motile rods. The temperature range for growth was 4–15 °C, with optimum growth at 12 °C and at approximately pH 6.0–9.0. Strain 170T contained C16 : 1 ω7c, C16 : 0, C12 : 1 3-OH and C18 : 1 ω7c as major fatty acids. The genomic DNA G+C content was 42.9 mol%. On the basis of phenotypic characterization, phylogenetic analysis and DNA–DNA relatedness data, strain 170T is considered to represent a novel species of the genus Glaciecola, for which the name Glaciecola psychrophila is proposed. The type strain is 170T (=CGMCC 1.6130T=JCM 13954T).

Strain UST040317-058T, comprising non-pigmented, rod-shaped, facultatively anaerobic, Gram-negative cells that are motile by means of single polar flagella, was isolated from the surface of a marine sponge (Ircinia dendroides) collected from the Mediterranean Sea. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a separate cluster with the recognized bacterium Shewanella algae IAM 14159T, with which it showed a sequence similarity of 95.0 %. The sequence similarity between strain UST040317-058T and its other (six) closest relatives ranged from 91.6 to 93.8 %. Strain UST040317-058T showed oxidase, catalase and gelatinase activities. The typical respiratory quinones for shewanellas, menaquinone MK-7 and ubiquinones Q-7 and Q-8, were also detected. The predominant fatty acids in strain UST040317-058T were i15 : 0, 16 : 0, 17 : 1ω8c and summed feature 3 (comprising i15 : 0 2-OH and/or 16 : 1ω7c), altogether representing 56.9 % of the total. The DNA G+C content was 39.9 mol%. The strain could be differentiated from other Shewanella species by its inability to reduce nitrate or produce H2S and by 10–22 additional phenotypic characteristics. On the basis of the phylogenetic and phenotypic data presented in this study, strain UST040317-058T represents a novel species in the genus Shewanella, for which the name Shewanella irciniae sp. nov. is proposed. The type strain is UST040317-058T (=JCM 13528T=NRRL B-41466T).