Dyadobacter chenhuakuii sp. nov., Dyadobacter chenwenxiniae sp. nov., and Dyadobacter fanqingshengii sp. nov., isolated from soil of the Qinghai-Tibetan Plateau

Six novel bacterial strains, designated CY22^T, CY357, LJ419^T, LJ53, CY399^T and CY107 were isolated from soil samples collected from the Qinghai-Tibetan Plateau, PR China. Cells were aerobic, rod-shaped, yellow-pigmented, catalase- and oxidase-positive, Gram-stain-negative, non-motile and non-spore-forming. All strains were psychrotolerant and could grow at 0 °C. The results of phylogenetic and phylogenomic analyses, based on 16S rRNA gene sequences and core genomic genes, indicated that the three strain pairs (CY22^T/CY357, LJ419^T/LJ53 and CY399^T/CY107) were closely related to members of the genus Dyadobacter and clustered tightly with two species with validly published names, Dyadobacter alkalitolerans 12116^T and Dyadobacter psychrophilus BZ26^T. Values of digital DNA-DNA hybridization between genome sequences of the isolates and other strains from the GenBank database in the genus Dyadobacter were far below the 70.0 % threshold. The genomic DNA G+C content of these six strains ranged from 45.2 to 45.8 %. The major cellular fatty acids of all six strains were iso-C_15 : 0 and summed feature 3 (comprising C_16 : 1 ω7c and/or C_16 : 1 ω6c). MK-7 was the only respiratory quinone, and phosphatidylethanolamine was the predominant polar lipid for strains CY22^T, LJ419^T and CY399^T. On the basis of the phenotypic, phylogenetic and genomic evidence presented, these six strains represent three novel members of the genus Dyadobacter, for which the names Dyadobacter chenhuakuii sp. nov., Dyadobacter chenwenxiniae sp. nov. and Dyadobacter fanqingshengii sp. nov. are proposed. The type strains are CY22^T (= GDMCC 1.3045^T = KCTC 92299^T), LJ419^T (= GDMCC 1.2872^T = JCM 33794^T) and CY399^T (= GDMCC 1.3052^T = KCTC 92306^T), respectively.

Hymenobacter terrestris sp. nov. and Hymenobacter lapidiphilus sp. nov., isolated from regoliths in Antarctica

A group of four psychrotrophic bacterial strains was isolated on James Ross Island (Antarctica) in 2013. All isolates, originating from different soil samples, were collected from the ice-free northern part of the island. They were rod-shaped, Gram-stain-negative, and produced moderately slimy red-pink pigmented colonies on R2A agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, whole-genome sequencing, MALDI-TOF MS, rep-PCR analyses, chemotaxonomic methods and extensive biotyping was used to clarify the taxonomic position of these isolates. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates belonged to the genus Hymenobacter. The closest relative was Hymenobacter humicola CCM 8763^T, exhibiting 98.3 and 98.9% 16S rRNA pairwise similarity with the reference isolates P5342^T and P5252^T, respectively. Average nucleotide identity, digital DNA-DNA hybridization and core gene distances calculated from the whole-genome sequencing data confirmed that P5252^T and P5342^T represent two distinct Hymenobacter species. The menaquinone systems of both strains contained MK-7 as the major respiratory quinone. The predominant polar lipids for both strains were phosphatidylethanolamine and one unidentified glycolipid. The major components in the cellular fatty acid composition were summed feature 3 (C_16:1 ω7c/C_16:1ω6c), C_16:1ω5c, summed feature 4 (anteiso-C_17:1 B/iso-C_17:1 I), anteiso-C_15:0 and iso-C_{15 : 0} for all isolates. Based on the obtained results, two novel species are proposed, for which the names Hymenobacter terrestris sp. nov. (type strain P5252^T=CCM 8765^T=LMG 31495^T) and Hymenobacter lapidiphilus sp. nov. (type strain P5342^T=CCM 8764^T=LMG 30613^T) are suggested.

Pontibacter fetidus sp. nov. and Pontibacter burrus sp. nov., isolated from the soil

Two novel strains, BT213^T and BT327^T, were isolated from the soil collected in Uijeongbu city, Korea. Cells of strains were Gram negative, aerobic, and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains BT213^T and BT327^T formed two distinct lineages within the family Hymenobacteraceae (order Cytophagales, class Cytophagia). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BT213^T and BT327^T belonged to the genus Pontibacter. Strain BT213^T showed the highest similarities of 97.8% with Pontibacter deserti JC215^T. Strain BT327^T showed the highest sequence similarity of 96.5% with Pontibacter mucosus PB3^T. Optimal growth occurred at 25 °C, pH 7, and in the absence of NaCl. The major cellular fatty acid of strains BT213^T and BT327^T were iso-C_15:0 and summed feature 4 (iso-C_17:1 I/anteiso-C_17:1 B). Strains BT213^T and BT327^T had MK-7 as major respiratory quinone and phosphatidylethanolamine as major polar lipids. The genome size of strains BT213^T and BT327^T were 4,072,018 bp and 4,314,171 bp, respectively. The genomic G + C mol% of strains BT213^T and BT327^T are 45.6% and 46.1%, respectively. Based on biochemical, chemotaxonomic, and phylogenetic analysis, two novel species Pontibacter fetidus BT213^T (KCTC 72345^T = NBRC 114379^T) and Pontibacter burrus BT327^T (KCTC 72412^T = NBRC 114376^T) are proposed as type strains.

Aquirufa rosea sp. nov., isolated from a freshwater lake

A bacterial strain designated CAR-16^T was isolated from a freshwater lake in Taiwan and characterized using the polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, motile by gliding, rod-shaped and formed rose-colored colonies. Optimal growth occurred at 30 °C, pH 7 and with 0 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that CAR-16^T represented a member of the family Cytophagaceae and formed a phylogenetic lineage in the genus Aquirufa. CAR-16^T was most closely related to Aquirufa nivalisilvae 59G-WUEMPEL^T with a 99.7 % 16S rRNA gene sequence similarity. CAR-16^T showed 71.2-79.5 % average nucleotide identity and 17.8-21.7 % digital DNA-DNA hybridization identity with the strains of other species of the genus Aquirufa. The major fatty acids of strain CAR-16^T were iso-C_15 : 0, iso-C_15 : 0 3-OH, C_16 : 1ω5c and summed feature 3 (C_16 : 1ω7c/C_16 : 1ω6c and/or iso-C_15 : 0 2-OH). The polar lipid profile consisted of a mixture of phosphatidylethanolamine and several uncharacterized aminophospholipids, phospholipids and lipids. The major isoprenoid quinone was MK-7. The genomic DNA G+C content of CAR-16^T was 38.8 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, CAR-16^T should be classified as representing a novel species of the genus Aquirufa, for which the name Aquirufa rosea sp. nov. is proposed. The type strain is CAR-16^T (=BCRC 81153^T=LMG 30923^T=KCTC 62869^T).

Hymenobacter sediminis sp. nov., isolated from lake sediment

A Gram-stain-negative, facultatively aerobic, rod-shaped, motile by gliding and pink-pigmented bacterial strain, designated ELS1360^T, was isolated from a lake sediment sample collected in Inner Mongolia, PR China. Strain ELS1360^T grew optimally at 33 °C, at pH 6.5-7.0 and without NaCl. Strain ELS1360^T exhibited 97.3, 97.1 and 96.9 % 16S rRNA gene sequence similarities to Hymenobacter aquatilis HMF3095^T, Hymenobacter luteus JCM 30328^T and Hymenobacter latericoloratus JCM 30327^T, respectively, and 90.4-96.9 % to other members of the genus Hymenobacter. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain ELS1360^T belonged to the genus Hymenobacter and clustered with H. luteus JCM 30328^T and H. latericoloratus JCM 30327^T. The predominant cellular fatty acids were iso-C_15:0, summed feature 3 and C_16:1ω5c. Strain ELS1360^T contained MK-7 as the sole menaquinone. The major polar lipids contained phosphatidylethanolamine and two unidentified lipids. The genomic DNA G+C content of strain ELS1360^T was 57.1 mol%. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain ELS1360^T represents a novel species within the genus Hymenobacter, for which the name Hymenobacter sediminis sp. nov. is proposed. The type strain is ELS1360^T (=KCTC 62449^T=MCCC 1H00319^T).

Siphonobacter curvatus sp. nov., isolated from a freshwater river

A novel orange-pigmented, Gram-stain-negative and strictly aerobic bacterium, designated strain HR-U^T, was isolated from a water sample of the Han River located in the Republic of Korea. Cells were catalase-positive and oxidase-positive, and non-motile curved rods without flagella. The strain grew at 5-35 °C (optimum 25 °C), pH 6-10 (optimum of 7-8) and 0-3 % (w/v) NaCl (optimum 0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-U^T formed a tight phylogenic lineage with Siphonobacter aquaeclarae DSM 21668^T and 'Siphonobacter intestinalis' 63MJ-2. The 16S rRNA gene sequence comparison of strain HR-U^T and other reported type strains showed that it shared the highest sequence similarity to S. aquaeclarae DSM 21668^T (96.9 %) and 'S. intestinalis' 63MJ-2 (96.6 %), and had lower similarities than 87.0 % to other bacteria with validly published names. Average nucleotide identity and in silico DNA-DNA hybridization values between strain HR-U^T and the most closely related strain S. aquaeclarae were 71.7 and 18.4 %, respectively. The major respiratory quinone was menaquinone-7, and the dominant fatty acids (>5 %) consisted of C16 : 1ω5c, summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 0 2-OH) and iso-C15 : 0. The polar lipids comprised phosphatidylethanolamine, four unidentified aminolipids and three unidentified lipids. The DNA G+C content was 47.9 mol%. Based on the genotypic, chemotaxonomic and phenotypic analyses, strain HR-U^T represents a novel species of the genus Siphonobacter, for which the name Siphonobacter curvatus sp. nov. is proposed. The type strain is HR-U^T (=KACC 19409^T=JCM 32267^T).

Ravibacter arvi gen. nov., sp. nov., isolated from farmland soil during development of new culture techniques

Two novel strains, J77-1^T and J76-1, were isolated from farmland soil and were taxonomically characterized by a polyphasic approach. Both strains were yellow, Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacteria. These strains were non-sporulating, catalase-positive and oxidase-negative. J77-1^T and J76-1 were able to grow at 15-40 °C, pH 5.0-10.0, and 0-1.0 % (w/v) NaCl concentration. Phylogenetic analyses revealed that both strains formed a distinct separate lineage within the family Cytophagaceae of the phylum Bacteroidetes. J77-1^T and J76-1 showed low 16S rRNA gene sequence similarity to the most closely related type strain Dyadobacter koreensis WPCB159^T (85.09 %) and exhibited less than 85.0 % sequence similarity with other members of the family Cytophagaceae. The pairwise sequence similarity between strains J77-1^T and J76-1 was observed to be 99.86 %. In both strains, the only respiratory quinone was menaquinone-7 (MK-7); the major polar lipid was phosphatidylethanolamine; and the major fatty acids were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, iso-C15 : 0, iso-C17 : 0 3-OH C16 : 1ω5c, and C16 : 0 3-OH. The genomic DNA G+C content values of J77-1^T and J76-1 were 50.1 and 50.9 mol%, respectively. On the basis of the results of phenotypic, genotypic and phylogenetic analysis, J77-1^T represents a novel species of a novel genus, for which the name Ravibacter arvi gen. nov., sp. nov. is proposed, within the family Cytophagaceae. The type strain of Ravibacter arvi is J77-1^T (=KEMB 9005-548^T=KACC 19172^T=JCM 31920^T), and J76-1 is an additional strain.

Hymenobacter aquaticus sp. nov., a radiation-resistant bacterium isolated from a river

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterial strain, designated 16F3PT, was isolated from the Han River, South Korea, and characterized taxonomically using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed 16F3PT to be within the genus Hymenobacter, and most closely related to Hymenobacterchitinivorans Txc1T (98.62 %) and Hymenobacterelongatus VUG-A112T (98.46 %). The phylogenetic distance from other species of the genus Hymenobacter with validly published names was greater than 4 % (i.e. sequence similarity was less than 96.0 %). Chemotaxonomic data also supported the classification of strain 16F3PT within the genus Hymenobacter. C16 : 0 (19.8 %), summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 15.4 %) and iso-C15 : 0 (13.0 %) were the major fatty acids, MK-7 was the predominant respiratory quinone, and phosphatidylethanolamine was the major polar lipid. The G+C content of the genomic DNA of strain 16F3PT was 61.9 mol%. DNA-DNA hybridization experiments showed that the values for DNA-DNA relatedness between strain 16F3PT and the phylogenetically closest neighbours were below 19 %. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain 16F3PT represents a novel species of the genus Hymenobacter, for which the name Hymenobacter aquaticus sp. nov. is proposed. The type strain is 16F3PT (=KCTC 52194T=JCM 31653T).

Spirosoma swuense sp. nov., isolated from wet soil

Strain JBM2-3T, a pale-yellow-coloured, aerobic, catalase-negative, oxidase-positive and Gram-stain-negative bacterium, was isolated from wet soil. The isolate grew aerobically at 25-30 °C (optimum 25 °C), pH 6.0-8.0 (optimum pH 7.0) and in the presence of 0-0.5 % (w/v) NaCl (optimum 0 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain JBM2-3T belonged to the genus Spirosoma, with a sequence similarity of 96.2 % with Spirosoma panaciterrae Gsoil 1519T. The strain showed the typical chemotaxonomic characteristics of the genus Spirosoma, with the presence of menaquinone 7 as the respiratory quinone; the major fatty acids were summed feature 3 (composed of C16: 1ω6c/ω7c), C16: 1ω5c and iso-C15: 0. The DNA G+C content of strain JBM2-3T was 47.4 mol%. The polar lipid profile contained major amounts of phosphatidylethanolamine and aminophospholipids. On the basis of its phenotypic and genotypic properties, and phylogenetic distinctiveness, strain JBM2-3T should be classified as a representative of a novel species in the genus Spirosoma, for which the name Spirosoma swuense sp. nov. is proposed. The type strain is JBM2-3T (=KCTC 52176T=JCM 31298T).

Rufibacter ruber sp. nov., isolated from fragmentary rock

A red-pigmented, Gram-stain-negative, rod-shaped, aerobic bacterium, designated strain CCM 8646T, was isolated from stone fragments in James Ross Island, Antarctica. Strain CCM 8646T was able to grow from 10 to 40 °C, in the presence of up to 1 % (w/v) NaCl and at pH 7.0-11.0. Analysis of the 16S rRNA gene sequence placed strain CCM 8646T in the genus Rufibacter with the closest relative being Rufibacter roseus H359T (97.07 % 16S rRNA gene sequence similarity). The digital DNA-DNA hybridization values between strain CCM 8646T and R. roseus H359T were low (21.30±2.34 %). The major quinone was menaquinone MK-7. The polar lipids comprised phosphatidylethanolamine, an unknown aminoglycolipid and six unknown polar lipids. The G+C content of strain CCM 8646T was 51.54 mol%. On the basis of phenotypic, chemotaxonomic and genotyping results, strain CCM 8646T is considered to represent a novel species within the genus Rufibacter, for which the name Rufibacter ruber sp. nov. is proposed. The type strain is CCM 8646T (=LMG 29438T).

Emticicia paludis sp. nov., isolated from wetland freshwater

A novel bacterium, designated HMF3850T, was isolated from freshwater collected from the Gyeong-an wetland, Republic of Korea. Cells were Gram-stain-negative, aerobic, straight rods, non-motile, and oxidase- and catalase-positive. Growth was observed at pH 6.0-8.0 and at 10-30 °C on R2A agar. Comparative analysis of 16S rRNA gene sequences revealed that strain HMF3850T is a member of the genus Emticicia, sharing highest sequence similarities with Emticicia aquatica HMF2925T (96.7 % 16S rRNA gene sequence similarity), Emticicia sediminis JBR12T (95.0 %), Emticicia ginsengisoliGsoil 085T (94.9 %) and Emticicia oligotrophica DSM 17448T (94.7 %). The major fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The predominant respiratory quinone was MK-7. The major polar lipids were phosphatidylethanolamine, phosphatidylinositol, one unidentified aminophospholipid, two unidentified aminolipids and eight unidentified polar lipids. The DNA G+C content was 38.5 mol %. On the basis of the evidence presented in this study, strain HMF3850T represents a novel species of the genus Emticicia, for which the name Emticicia paludis sp. nov. is proposed. The type strain is HMF3850T (=KCTC 42851T=CECT 9087T).

Hymenobacter humi sp. nov., a bacterium isolated from soil

A red-pink coloured, Gram-negative, rod-shaped bacterium designated as strain DG31A(T) was isolated from soil collected in Seoul, South Korea. The isolate was found to grow optimally at 25 °C on R2A agar. The highest degrees of 16S rRNA gene sequence similarities of the strain were found with Hymenobacter arizonensis JCM 13504(T) (98.0 %), Hymenobacter glaciei VUG-A130(T) (96.1 %), Hymenobacter soli PB17(T) (95.2 %), Hymenobacter antarcticus VUG-A42aa(T) (94.7 %) and Hymenobacter chitinivorans Txc1(T) (92.8 %). The DNA G+C content of the novel strain, DG31A(T), was determined to be 60.8 mol%. Chemotaxonomic data revealed that the major fatty acids were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c; 26.7 %), C16:1 ω5c (18.9 %) and anteiso-C15:0 (12.9 %); the major polar lipid was identified as phosphatidylethanolamine; the polyamine pattern was found to contain sym-homospermidine; and the major quinone was identified as MK-7. The DNA-DNA relatedness of strain DG31A(T) with respect to H. arizonensis JCM 13504(T) was 19.5 ± 2.9 % (reciprocal, 19.3 ± 0.6 %). Based on these data, strain DG31A(T) should be classified within the genus Hymenobacter as a novel species for which the name Hymenobacter humi sp. nov. is proposed, with the type strain DG31A(T) (=KCTC 32523(T) = JCM 19635(T)).

Pontibacter diazotrophicus sp. nov., a novel nitrogen-fixing bacterium of the family Cytophagaceae

Few diazotrophs have been found to belong to the family Cytophagaceae so far. In the present study, a Gram-negative, rod-shaped bacterium that forms red colonies, was isolated from sands of the Takalamakan desert. It was designated H4X^T. Phylogenetic and biochemical analysis indicated that the isolate is a new species of the genus Pontibacter. The 16S rRNA gene of H4X^T displays 94.2–96.8% sequence similarities to those of other strains in Pontibacter. The major respiratory quinone is menaquinone-7 (MK-7). The DNA G+C content is 46.6 mol%. The major cellular fatty acids are iso-C_15∶0, C_16∶1ω5c, summed feature 3 (containing C_16∶1ω6c and/or C_16∶1ω7c) and summed feature 4 (comprising anteiso-C_17∶1B and/or iso-C_17∶1I). The major polar lipids are phosphatidylethanolamine (PE), one aminophospholipid (APL) and some unknown phospholipids (PLs). It is interesting to see that this bacterium can grow very well in a nitrogen-free medium. PCR amplification suggested that the bacterium possesses at least one type of nitrogenase gene. Acetylene reduction assay showed that H4X^T actually possesses nitrogen-fixing activity. Therefore, it can be concluded that H4X^T is a new diazotroph. We thus referred it to as Pontibacter diazotrophicus sp. nov. The type strain is H4X^T ( = CCTCC AB 2013049^T = NRRL B-59974^T).

Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov., novel members of the family Cytophagaceae, isolated from seawater

Two strains, designated GCR0103(T) and GYR3121(T), were isolated from seawater of the Saemangeum Embankment in Jeollabuk-do, Korea. The cells of the two strains were Gram-reaction-negative and non-motile, and formed multicellular filaments. The colonies of the two strains were pink-pigmented and able to grow at 15-37 °C (optimum 25 °C) on R2A and NA medium. Strains GCR0103(T) and GYR3121(T) grew at pH 6.5-10 (optimum pH 7.5) and pH 5.5-9.5 (optimum pH 7.5), and within NaCl ranges of 0-0.4% and 0-1%, respectively. The polar lipid profiles of the two strains contained phosphatidylethanolamine, five unknown aminolipids, an unknown phospholipid and four or five unknown lipids. The DNA G+C contents of strains GCR0103(T) and GYR3121(T) were 56.0 and 54.5 mol%, respectively. The respiratory quinone detected in both strains was MK-7. The 16S rRNA gene sequence similarity between GCR0103(T) and GYR3121(T) was 95.5 %. The 16S rRNA gene sequence similarities of the two strains to closely related reference strains were less than 89 %. Phylogenetic analysis based on 16S rRNA genes showed that GCR0103(T) and GYR3121(T) formed a distinct phyletic line in the family Cytophagaceae. On the basis of the phenotypic, chemotaxonomic and phylogenetic properties, strains GCR0103(T) and GYR3121(T) represent two novel species in a new genus within the family Cytophagaceae, for which the names Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov. are proposed. The type strain of Nibrella saemangeumensis is GCR0103(T) ( = KACC 16453(T) = JCM 17927(T)) and the type strain of Nibrella viscosa is GYR3121(T) ( = KACC 16447(T) = JCM 17925(T)).

Description of Hymenobacter arizonensis sp. nov. from the southwestern arid lands of the United States of America

Strain OR362-8(T) was isolated from a biological soil crust sample collected from the southwestern arid lands of the United States of America, using BG11-PGY medium. Cells of OR362-8(T) were found to be rod shaped; occur singly, as pairs and in groups; non-motile; positive for catalase, oxidase, phosphatase and gelatinase; hydrolyze starch; contain iso-C(15:0), anteiso-C(15:0), iso-C(15:1)G, C(16:1ω5c) and summed feature 3 (C(16:1(ω7c))/iso-C(15:0) 2OH as defined by the MIDI system) as the major fatty acids; and MK-7 as the sole respiratory quinone. A BLAST sequence similarity search using 16S rRNA gene sequence of OR362-8(T) identified Hymenobacter as the nearest genus with a similarity of 90.4-96.9 %. The phylogenetic analyses based on the phenetic methods UPGMA, NJ, ME and DNA parsimony resulted in the clustering of OR362-8(T) with Clade 1 Hymenobacter species represented by Hymenobacter glaciei, Hymenobacter antarcticus, Hymenobacter flocculans, Hymenobacter metalli and Hymenobacter soli with the closest being the Hymenobacter glaciei (96.9 % 16S rRNA gene sequence similarity). Besides the strong phylogentic affiliation, OR362-8(T) also exhibited significant phenotypic and chemotaxonomic differences with the members of Clade 1 Hymenobacter spp. More importantly, the DNA G+C content (mol%) of OR362-8(T) is very high (70 %) compared to the nearest species identified by phylogenetic analysis. Based on the phylogenetic, phenotypic and chemotaxonomic characteristics, OR362-8(T) was assigned to a novel species for which we propose here the name Hymenobacter arizonensis sp. nov., with OR362-8(T) (=ATCC BAA 1266(T) = DSM 17860(T) = JCM 13504(T)) as the type strain.

Fontibacter ferrireducens sp. nov., an Fe(III)-reducing bacterium isolated from a microbial fuel cell

A novel, dissimilatory Fe(III)-reducing bacterium, designated strain SgZ-2(T), which could couple glucose oxidation to iron reduction for energy conservation, was isolated from a microbial fuel cell. The isolate was Gram-staining-negative, catalase-positive, oxidase-negative and facultatively anaerobic. The strain was able to grow on tryptic soy agar at 15-37 °C and in the presence of 0-5 % (w/v) NaCl. The predominant cellular fatty acids (>5 %) were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1ω9c; the major respiratory quinone was MK-7; the major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and three other unidentified lipids; and the DNA G+C content was 55.3 mol%. Phylogenetic analyses based on 16S rRNA sequences showed that the novel strain was most closely related to Fontibacter flavus CC-GZM-130(T) (99.9 % sequence similarity), and was a member of the family Cyclobacteriaceae. The levels of DNA-DNA relatedness observed between strain SgZ-2(T) and F. flavus CCM 7650(T) (<41 %) indicated that the two strains represented two distinct species. Based on phylogenetic analyses and phenotypic characteristics, strain SgZ-2(T) represents a novel species of the genus Fontibacter, for which the name Fontibacter ferrireducens sp. nov. is proposed. The type strain is SgZ-2(T) ( = CCTCC M 2011498(T)  = KACC 16525(T)).

Experimentally induced marine flexibacteriosis in Atlantic salmon smolts Salmo salar. II. Pathology

The fish disease marine flexibacteriosis is characterised by necrotic lesions on the body, head, fins, and occasionally gills, with erosive lesions on the external surface as the prominent clinical sign. In Australia, the main species affected are Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in sea-cage culture in Tasmania. Using a dose-dependent trial to determine pathology, 2 forms of the disease were noted in Atlantic salmon. The acute form occurs within 2 to 3 d after inoculation at high doses (1 x 10(8) cells ml(-1)) and is characterised by the disintegration of the epithelium. The chronic form of the disease began as small superficial blisters of the epidermis, which develop into ulcerative lesions that leave musculature exposed. The predominant lesion sites were the dorsum and pectoral fins. Jaws were commonly affected, and gill necrosis was also noted. Behaviour of Atlantic salmon as well as the conditions under which they were kept contribute to the size and distribution of lesions observed. Lack of an inflammatory response in pathology and rapid and destructive mortalities observed in higher inoculum doses suggested a role of toxins in the pathogenesis of Tenacibaculum maritimum. This is the first study to examine the development of marine flexibacteriosis lesions and to utilise immunohistochemistry to verify that the bacteria observed in histology was T. maritimum.

Spirosoma spitsbergense sp. nov. and Spirosoma luteum sp. nov., isolated from a high Arctic permafrost soil, and emended description of the genus Spirosoma

Two pigmented, Gram-negative, non-motile, pleomorphic rod-shaped bacteria (strains SPM-9(T) and SPM-10(T)) were isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway. A third isolate (strain M5-H2) was recovered from the same soil sample after the sample had been exposed to simulated Martian environmental conditions. The three strains were characterized taxonomically by using a polyphasic approach. Phylogenetic, chemotaxonomic, physiological and morphological analyses demonstrated that the three isolates were most closely related to members of the genus Spirosoma. 16S rRNA gene sequence data indicated that the three isolates could be divided into two clusters: (i) strain SPM-9(T) and (ii) strains SPM-10(T) and M5-H2. This grouping was confirmed by DNA-DNA hybridization experiments. Strains SPM-9(T) and SPM-10(T) exhibited 92 % 16S rRNA gene sequence similarity to both Spirosoma linguale LMG 10896(T) and Spirosoma rigui WPCB 118(T). The major fatty acids present in all three isolates were summed feature 3 (comprising iso-C(15:0) 2-OH and/or C(16 : 1)omega7c; 43.0-48.2 % of the total), C(16 : 1)omega5c (19.1-21.3 %), C(16 : 0) (6.7-7.3 %), iso-C(17 : 0) 3-OH (4.7-6.0 %) and iso-C(15 : 0) (2.6-5.7 %). On the basis of their phenotypic and genotypic characteristics, the new strains are assigned to two novel species of the genus Spirosoma, for which the names Spirosoma spitsbergense sp. nov. and Spirosoma luteum sp. nov. are proposed. The type strain of Spirosoma spitsbergense is SPM-9(T) (=NCIMB 14407(T)=DSM 19989(T)) and the type strain of Spirosoma luteum is SPM-10(T) (=NCIMB 14406(T)=DSM 19990(T)). An emended description of the genus Spirosoma is also proposed.

Proposal of Algoriphagus vanfongensis sp. nov., transfer of members of the genera Hongiella Yi and Chun 2004 emend. Nedashkovskaya et al. 2004 and Chimaereicella Tiago et al. 2006 to the genus Algoriphagus, and emended description of the genus Algoriphagus Bowman et al. 2003 emend. Nedashkovskaya et al. 2004

A taxonomic study of a novel marine, heterotrophic, non-gliding, halotolerant and light-pink-pigmented bacterium was carried out using a polyphasic approach. 16S rRNA gene sequence analysis revealed that strain KMM 6241T is a member of the phylum Bacteroidetes. Strain KMM 6241T formed a cluster with the genera Algoriphagus, Chimaereicella and Hongiella with sequence similarities of 94.0–98.2 %. Hongiella ornithinivorans was the closest relative of the novel isolate. Comparative analysis of phenotypic, chemotaxonomic and genotypic characteristics of strain KMM 6241T and representatives of the genera Algoriphagus, Chimaereicella and Hongiella revealed many similar features. Consequently, phylogenetic evidence supported by phenotypic and genotypic similarities support the transfer of members of the genera Chimaereicella and Hongiella to the genus Algoriphagus and the establishment of a novel species, Algoriphagus vanfongensis sp. nov., with strain KMM 6241T (=DSM 17529T=KCTC 12716T) as the type strain.

Hymenobacter xinjiangensis sp. nov., a radiation-resistant bacterium isolated from the desert of Xinjiang, China

A Gram-negative, non-motile, rod-shaped and pink-pigmented bacterium, designated strain X2-1gT, was isolated from a mixture of sand samples collected from the desert of Xinjiang, China, after exposure of the sand to 8 kGy gamma radiation. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that this isolate represents a novel member of the genus Hymenobacter, with low sequence similarities (<97 %) to recognized Hymenobacter species. Biolog GN2 assays supported this conclusion. Optimum growth was observed at pH 7 and 28 °C. The strain contained MK-7 as the predominant menaquinone and the major fatty acids were iso-C15 : 0 (19.5 %), C16 : 1 ω7c/iso-C15 : 0 2-OH (20.2 %), C16 : 1 ω5c (10.6 %), C16 : 0 (6.2 %), anteiso-C17 : 1 B/iso-C17 : 1 I (8.5 %) and C18 : 0 (6.5 %). The DNA G+C content was 54 mol% (T m). On the basis of the polyphasic evidence presented, it is proposed that strain X2-1gT represents a novel species of the genus Hymenobacter, for which the name Hymenobacter xinjiangensis sp. nov. is proposed. The type strain is X2-1gT (=CCTCC AB 206080T =IAM 15452T).

Dyadobacter koreensis sp. nov., isolated from fresh water

A non-motile, rod-shaped, light-yellow-pigmented bacterium, designated strain WPCB159T, was isolated from freshwater samples collected from the Woopo wetland in Korea. The cells were Gram-negative, aerobic and catalase- and oxidase-positive. The major fatty acids were C16 : 1 ω7c (34.8 %), iso-C15 : 0 (24.2 %) and C16 : 0 (9.4 %). The DNA G+C content was 44 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain WPCB159T forms a lineage within the genus Dyadobacter (family ‘Flexibacteraceae’) and is closely related to Dyadobacter hamtensis HHS 11T (97.8 % sequence similarity) and to other members of the genus Dyadobacter (95.2–96.8 % sequence similarity). The phenotypic characteristics and DNA–DNA hybridization relatedness data indicate that strain WPCB159T should be distinguished from D. hamtensis HHS 11T. On the basis of the evidence presented in this study, strain WPCB159T represents a novel species of the genus Dyadobacter, for which the name Dyadobacter koreensis sp. nov. is proposed. The type strain is WPCB159T (=KCTC 12537T=NBRC 101116T).

Fulvivirga kasyanovii gen. nov., sp. nov., a novel member of the phylum Bacteroidetes isolated from seawater in a mussel farm

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).

Persicitalea jodogahamensis gen. nov., sp. nov., a marine bacterium of the family ‘Flexibacteraceae’, isolated from seawater in Japan

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).

Dyadobacter beijingensis sp. nov., isolated from the rhizosphere of turf grasses in China

Strain A54T was isolated from rhizospheric soil of turf grasses irrigated with reclaimed water in Taoranting Park, Beijing, China. Phenotypic, chemotaxonomic and polygenetic analyses established the affiliation of the isolate to the genus Dyadobacter. Strain A54T possessed 97.7, 94.4 and 94.7 % 16S rRNA gene sequence similarity with respect to the type strains of Dyadobacter fermentans, D. hamtensis and D. crusticola, respectively. Furthermore, DNA–DNA hybridization did not show significant relatedness (<25 % hybridization) between strain A54T and D. fermentans ATCC 700827T. Therefore, these results indicate that strain A54T belongs to a novel species of the genus Dyadobacter, for which the name Dyadobacter beijingensis sp. nov. is proposed. The type strain is strain A54T (=CGMCC 1.6375T=JCM 14200T).

Biosynthesis of bile acids in a variety of marine bacterial taxa

Several marine bacterial strains, which were isolated from seawater off the island Dokdo, Korea, were screened to find new bioactive compounds such as antibiotics. Among them, Donghaeana dokdonensis strain DSW-6 was found to produce antibacterial agents, and the agents were then purified and analyzed by LC-MS/MS and 1D- and 2D-NMR spectrometries. The bioactive compounds were successfully identified as cholic acid and glycine-conjugated glycocholic acid, the 7alpha-dehydroxylated derivatives (deoxycholic acid and glycodeoxycholic acid) of which were also detected in relatively small amounts. Other masine isolates, taxonomically different from DSW-6, were also able to produce the compounds in a quite different production ratio from DSW-6. As far as we are aware of, these bile acids are produced by specific members of the genus Streptomyces and Myroides, and thought to be general secondary metabolites produced by a variety of bacterial taxa that are widely distributed in the sea.

Pontibacter akesuensis sp. nov., isolated from a desert soil in China

A Gram-negative, non-motile, rod-shaped bacterium, designated strain AKS 1T, was isolated from a desert soil sample collected from Akesu, XinJiang Province, China. A taxonomic study, including phylogenetic analysis based on 16S rRNA gene sequences and phenotypic characteristics, was performed on the novel isolate. The predominant menaquinone of strain AKS 1T was MK-7. The major fatty acids included i-C15 : 0, ai-C17 : 1 B/i-C17 : 1 I and i-C17 : 0 3-OH. The G+C content of the DNA was 51.4 mol%. Based on the results of phenotypic and genotypic characteristics, strain AKS 1T should be assigned as representing a novel species of the genus Pontibacter, for which the name Pontibacter akesuensis is proposed. The type strain is AKS 1T (=KCTC 12758T=CCTCC AB 206086T).

Runella limosa sp. nov., isolated from activated sludge

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 EMB111Twere iso-C15 : 0, C16 : 1ω5c, iso-C17 : 03-OH, iso-C15 : 03-OH, C16 : 03-OH, C16 : 0and summed feature 3 (C16 : 1ω7cand/or iso-C15 : 02-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 EMB111Tformed a phyletic cluster with members of the genusRunellawithin the familyFlexibacteraceaeand was most closely related toRunella slithyformisATCC 29530Twith a 16S rRNA gene sequence similarity of 94.8 %. On the basis of chemotaxonomic data and molecular properties, strain EMB111Trepresents a novel species within the genusRunella, for which the nameRunella limosasp. nov. is proposed. The type strain is EMB111T(=KCTC 12615T=DSM 17973T).

Rhodonellum psychrophilum gen. nov., sp. nov., a novel psychrophilic and alkaliphilic bacterium of the phylum Bacteroidetes isolated from Greenland

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.

Cyclobacterium lianum sp. nov., a marine bacterium isolated from sediment of an oilfield in the South China Sea, and emended description of the genus Cyclobacterium

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.

Proposal of Hymenobacter norwichensis sp. nov., classification of 'Taxeobacter ocellatus', 'Taxeobacter gelupurpurascens' and 'Taxeobacter chitinovorans' as Hymenobacter ocellatus sp. nov., Hymenobacter gelipurpurascens sp. nov. and Hymenobacter chitinivorans sp. nov., respectively, and emended description of the genus Hymenobacter Hirsch et al. 1999

Two airborne bacterial isolates, NS/2 and NS/50(T), were examined in order to determine their taxonomic position. Their almost complete 16S rRNA gene sequences shared 95.9 % similarity. Sequence comparisons demonstrated that their next relatives are species of the genus Hymenobacter (93.6-95.7 % similarity) and the strains 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T) (90.5-96.4 %). Phylogenetic calculations indicated that these five strains together with the three recognized Hymenobacter species form a separate line of descent within the family 'Flexibacteraceae'. Isolates NS/2 and NS/50(T), as well as 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T), possessed the characteristics of the genus Hymenobacter, the quinone system menaquinone MK-7 and a polyamine pattern with the major polyamine being sym-homospermidine. Each of the five strains had complex, unique polar lipid profiles, with phosphatidylethanolamine and several unknown aminophospho-, amino-, phospho-, glyco- and polar lipids of which several compounds were also found in established Hymenobacter species. All the strains studied possessed fatty acids characteristic of Hymenobacter species, including major acids iso-C(15 : 0), anteiso-C(15 : 0), C(16 : 1)omega5c, summed feature 3 (C(16 : 1)omega7c/iso-C(15 : 0) 2-OH) and summed feature 4 (iso-C(17 : 1) I/anteiso-C(17 : 1) B). The five strains could be distinguished from each other and from the three established species of the genus Hymenobacter based on relatively low 16S rRNA gene sequence similarities (<97 %), unique polar lipids and differing fatty acid profiles and physiological characteristics. In conclusion, the description of four novel species of the genus Hymenobacter appears to be justified, for which the names Hymenobacter norwichensis sp. nov. (type strain NS/50(T)=LMG 21876(T)=DSM 15439(T)), Hymenobacter chitinivorans sp. nov. (type strain Txc1(T)=LMG 21951(T)=DSM 11115(T)), Hymenobacter gelipurpurascens sp. nov. (type strain Txg1(T)=LMG 21874(T)=DSM [corrected][11116(T)) and Hymenobacter ocellatus sp. nov. (type strain Myx 2105(T)=Txo1(T)=LMG 21873(T)=DSM 11117(T)) are proposed. For strain NS/2, a description only is provided without proposal of a name because its status as a novel species was not demonstrated unambiguously.

Effluviibacter roseus gen. nov., sp. nov., isolated from muddy water, belonging to the family "Flexibacteraceae"

A Gram-negative bacterial isolate (designated SRC-1(T)) was isolated from an occasional drainage system and characterized by a polyphasic approach to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequences affiliated strain SRC-1(T) with the family "Flexibacteraceae" of the phylum Bacteroidetes. It showed greatest sequence similarity to Pontibacter actiniarum KMM 6156(T) (95.5 %) followed by Adhaeribacter aquaticus MBRG1.5(T) (89.0 %) and Hymenobacter roseosalivarius DSM 11622(T) (88.9 %), but it differed from these micro-organisms in many phenotypic characteristics. Strain SRC-1(T) was an obligate aerobe and its cells were non-motile, irregular rods. The major fatty acids included mainly unsaturated and hydroxy fatty acids, including 17 : 1 iso I/anteiso B (36.7 %), 15 : 0 iso (15.8 %) and 17 : 0 iso 3-OH (10.3 %), and the DNA G+C content was 59.5 mol%. From the phenotypic and genotypic analyses it was clear that strain SRC-1(T) was quite different from members other genera in the family '"Flexibacteraceae". Therefore we conclude that strain SRC-1(T) represents a novel genus, for which the name Effluviibacter gen. nov., containing a single species Effluviibacter roseus sp. nov., is proposed. The type species of the genus is Effluviibacter roseus, the type strain of which is strain SRC-1(T) (=MTCC 7260(T)=DSM 17521(T)).

Emticicia oligotrophica gen. nov., sp. nov., a new member of the family 'Flexibacteraceae', phylum Bacteroidetes

An aquatic bacterium, strain GPTSA100-15T, was isolated on nutritionally poor medium TSBA100 (tryptic soy broth diluted 100 times and solidified with 1.5 % agarose) and characterized using a polyphasic approach. The isolate was unable to grow on commonly used nutritionally rich media such as tryptic soy agar, nutrient agar and Luria-Bertani agar. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was affiliated with the family 'Flexibacteraceae' in the phylum Bacteroidetes. Phylogenetically, it showed closest similarity (94.0 %) with an uncultured bacterial clone, HP1A92, detected in a sludge microbial community. Among the culturable bacteria, the isolate had highest 16S rRNA gene sequence similarity with Leadbetterella byssophila 4M15T (87.8 %). Sequence similarities with other members of the phylum Bacteroidetes were less than 85 %. The fatty acid profile of the isolate grown on TSBA100 indicated that the major fatty acid was iso-C15:0, which is also present in many members of the family 'Flexibacteraceae'. Cells of strain GPTSA100-15T are Gram-negative, strictly aerobic rods. The DNA G+C content of the isolate is 36.9 mol%. Results of phenotypic, chemotaxonomic and phylogenetic analyses clearly indicate that strain GPTSA100-15T represents a new genus within the family 'Flexibacteraceae'; the name Emticicia gen. nov. is proposed for the genus, with Emticicia oligotrophica sp. nov. as the type species. The type strain of Emticicia oligotrophica is GPTSA100-15T (=MTCC 6937T=DSM 17448T).

Hymenobacter rigui sp. nov., isolated from wetland freshwater

A non-motile, rod-shaped and pinkish-red-pigmented bacterium, designated strain WPCB131T, was isolated from freshwater of Woopo wetland, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that this isolate represents a novel member of the genus Hymenobacter with sequence similarities of 93.2–95.5 % to known Hymenobacter species. No other taxa in the phylum Bacteroidetes showed more than 90 % sequence similarity to the isolate. Cells were Gram-negative, oxidase-negative and catalase-positive. Optimum growth was observed at pH 6 and 30 °C. The major fatty acids were iso-C15 : 0 (34.8 %), C16 : 1 ω5c (15.0 %), anteiso-C17 : 1 B/iso-C17 : 1 I (14.4 %) and C16 : 1 ω7c/iso-C15 : 0 2-OH (13.8 %). The DNA G+C content of strain WPCB131T was 65 mol%. The isolate could be readily distinguished from other Hymenobacter species using a combination of phenotypic characters. On the basis of the polyphasic evidence presented in this study, it is proposed that strain WPCB131T (=IMSNU 14116T=KCTC 12533T=NBRC 101118T) represents a novel species, Hymenobacter rigui sp. nov.

Description of Fabibacter halotolerans gen. nov., sp. nov. and Roseivirga spongicola sp. nov., and reclassification of [Marinicola] seohaensis as Roseivirga seohaensis comb. nov

Bacterial strains UST030701-097T and UST030701-084T were isolated from a marine sponge in the Bahamas. Both strains were pink-pigmented, Gram-negative, strictly aerobic and chemo-organotrophic. Cells of strain UST030701-097T were short, curved rods with fast-gliding motility, whereas those of strain UST030701-084T were straight rods with a less rapid gliding motion. The two strains had MK-7 as the major respiratory quinone and did not produce flexirubin-type pigments. The DNA G+C contents of strains UST030701-097T and UST030701-084T were 42.5 and 43.7 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains belonged to the family ‘Flexibacteraceae’ of the phylum Bacteroidetes. 16S rRNA gene sequence similarity between strains UST030701-097T and UST030701-084T was 95.0 %; their closest relative was [Marinicola] seohaensis, with 93.3 % and 96.0 % sequence similarity, respectively. Phylogenetic tree topology indicated that the two strains belonged to the same lineage, but were on separate branches. Whilst strain UST030701-084T and [Marinicola] seohaensis were found on one branch, strain UST030701-097T was in another branch that had no species with validly published names. Based on the polyphasic taxonomic data obtained in the present study, we propose that strain UST030701-097T represents a novel genus and that strain UST030701-084T represents a novel species in the phylum Bacteroidetes. The genus Fabibacter gen. nov. is proposed, with strain UST030701-097T (=NRRL B-41220T=JCM 13334T) as the type strain of the type species, Fabibacter halotolerans sp. nov. Strain UST030701-084T (=NRRL B-41219T=JCM 13337T) is proposed as the type strain of Roseivirga spongicola sp. nov. In an earlier study, it was suggested that the genus Marinicola is a later heterotypic synonym of the genus Roseivirga. However, a formal proposal to reclassify [Marinicola] seohaensis, the only member of the genus Marinicola, has not yet been made. The results of phylogenetic analyses in this study support the reclassification of [Marinicola] seohaensis as Roseivirga seohaensis comb. nov.

Echinicola pacifica gen. nov., sp. nov., a novel flexibacterium isolated from the sea urchin Strongylocentrotus intermedius

The taxonomic position of three novel marine, heterotrophic, pigmented and agarolytic bacteria with gliding motility, isolated from the sea urchin Strongylocentrotus intermedius, was investigated. 16S rRNA gene sequence analysis revealed that strains KMM 6166, KMM 6172T and KMM 6173 are members of the phylum Bacteroidetes; their nearest neighbours were Belliella baltica and Hongiella marincola (similarities of 94.5 and 93.6 %, respectively). The DNA G+C content of the strains was 44–45 mol%. The predominant fatty acids were C15 : 0 iso, C16 : 1 ω5c, C17 : 1 iso ω9c, C17 : 0 iso 3-OH and summed feature 3 (C16 : 1 ω7c and/or C15 : 0 iso 2-OH). The major respiratory quinone was MK-7. Results of molecular experiments supported by phenotypic and chemotaxonomic data enabled the isolates to be classified as representatives of a novel species in a new genus, for which the name Echinicola pacifica gen. nov., sp. nov. is proposed. Echinicola pacifica is the type species of the genus Echinicola, and its type strain is KMM 6172T (=KCTC 12368T=LMG 23350T).

Algoriphagus terrigena sp. nov., isolated from soil

A Gram-negative, non-motile, non-spore-forming bacterial strain, DS-44T, was isolated from soil from Dokdo in Korea, and its taxonomic position was investigated by using a polyphasic approach. It grew optimally at 25 °C and in the presence of 2 % (w/v) NaCl. Strain DS-44T contained MK-7 as the predominant menaquinone and iso-C15 : 0 and C16 : 1 ω7c and/or iso-C15 : 0 2-OH as the major fatty acids. The DNA G+C content was 49·0 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DS-44T belongs to the genus Algoriphagus of the phylum Bacteroidetes. Similarity values between the 16S rRNA gene sequences of strain DS-44T and those of the type strains of recognized Algoriphagus species were in the range 93·8–95·7 %, making it possible to categorize strain DS-44T as a species that is separate from previously described Algoriphagus species. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain DS-44T (=KCTC 12545T=CIP 108837T) was classified in the genus Algoriphagus as the type strain of a novel species, for which the name Algoriphagus terrigena sp. nov. is proposed.

Direct and indirect effects of protist predation on population size structure of a bacterial strain with high phenotypic plasticity

We studied the impact of grazing and substrate supply on the size structure of a freshwater bacterial strain (Flectobacillus sp.) which showed pronounced morphological plasticity. The cell length varied from 2 to >40 microm and encompassed rods, curved cells, and long filaments. Without grazers and with a sufficient substrate supply, bacteria grew mainly in the form of medium-sized rods (4 to 7 microm), with a smaller proportion (<10%) of filamentous forms. Grazing experiments with the bacterivorous flagellate Ochromonas sp. showed that freely suspended cells of <7 microm were highly vulnerable to grazers, whereas filamentous cells were resistant to grazing and became enriched during predation. A comparison of long-term growth in carbon-limited chemostats with and without grazers revealed that strikingly different bacterial populations developed: treatments with flagellates were composed of >80% filamentous cells. These attained a biomass comparable to that of populations in chemostats without grazers, which were composed of medium-sized rods and c-shaped cells. Carbon starvation resulted in a fast decrease in cell length and a shift towards small rods, which were highly vulnerable to grazing. Dialysis bag experiments in combination with continuous cultivation revealed that filament formation was significantly enhanced even without direct contact of bacteria with bacterivores and was thus probably stimulated by grazer excretory products.

Chimaereicella alkaliphila gen. nov., sp. nov., a Gram-negative alkaliphilic bacterium isolated from a nonsaline alkaline groundwater

A Gram-negative bacterium designated AC-74(T) was isolated from a highly alkaline groundwater environment (pH 11.4). This organism formed rod-shaped cells, is strictly aerobic, catalase and oxidase positive, tolerates up to 3.0% NaCl, has an optimum growth temperature of 30 degrees C, but no growth occurs at 10 or 40 degrees C, and an optimum pH value of 8.0, but no growth occurs at pH 7.0 or 11.3. The predominant fatty acids are iso-15:0, iso-17:1 omega9c and 16:1 omega7c and or iso-15:2OH. The G+C content of DNA was 43.5mol%. The phylogenetic analyses of the sequences of the 16s RNA genes indicated that strain AC-74(T) belongs to the family "Flexibacteriaceae" and is phylogenetically equidistant ( approximately 94.5%) from the majority of the species of the genus Algoriphagus and from the genus Hongiella. Based on the phylogenetic analyses and distinct phenotypic characteristics, we are of the opinion that strain AC-74(T), represents a new species of the novel genus for which we propose the name Chimaereicella alkaliphila gen. nov., sp. nov.

Leadbetterella byssophila gen. nov., sp. nov., isolated from cotton-waste composts for the cultivation of oyster mushroom

A bacterial strain, designated 4M15T, was isolated from cotton-waste composts used as mushroom cultivation in South Korea. Properties of this isolate were studied on the basis of physiological and biochemical characteristics, fatty acid profile, isoprenoid quinone, DNA G+C content and phylogenetic position based on 16S rRNA gene sequence analysis. The strain was found to form a distinct phylogenetic lineage related to the family ‘Flexibacteraceae’ within the phylum ‘Bacteroidetes’. No recognized species showed >85 % 16S rRNA gene sequence similarity to strain 4M15T. The fatty acid profile of strain 4M15T included C16 : 1 ω7c/iso-C15 : 0 2-OH (30·5 %), iso-C15 : 0 (24·2 %), iso-C15 : 0 2-OH/C16 : 1 ω7c (15·9), iso-C17 : 0 3-OH (10·5 %) and C16 : 0 (5·6 %). The major isoprenoid quinone was menaquinone MK-7. The DNA G+C content was 33·0 mol%. Cells were Gram-negative, strictly aerobic, rod-shaped, non-motile, catalase-positive, oxidase-positive and flexirubin-positive. The strain hydrolysed aesculin, gelatin, starch and tyrosine. Several phenotypic tests could be used to differentiate strain 4M15T from other members of the family ‘Flexibacteraceae’. On the basis of the data presented, strain 4M15T should be assigned to the phylum ‘Bacteroidetes’ as a novel genus and species, for which the name Leadbetterella byssophila gen. nov., sp. nov. is proposed. The type strain is 4M15T (=KACC 11308T=DSM 17132T).

Roseivirga echinicomitans sp. nov., a novel marine bacterium isolated from the sea urchin Strongylocentrotus intermedius, and emended description of the genus Roseivirga

A novel strictly aerobic, heterotrophic, pink-pigmented, non-motile, Gram-negative, oxidase-, catalase-, β-galactosidase- and alkaline phosphatase-positive marine bacterium, designated strain KMM 6058T, was isolated from the sea urchin Strongylocentrotus intermedius and studied using a polyphasic taxonomic approach. The G+C content of the DNA of the isolate was 41·3 mol%. The predominant fatty acids were i15 : 1, i15 : 0, a15 : 0 and i17 : 0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 6058T formed a monophyletic clade with Roseivirga ehrenbergii, with 99 % similarity. On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacterium should be assigned to the genus Roseivirga as Roseivirga echinicomitans sp. nov. The type strain is KMM 6058T (=KCTC 12370T=LMG 22587T).

Dyadobacter hamtensis sp. nov., from Hamta glacier, located in the Himalayas, India

Strain HHS 11T was isolated from a water sample collected from the snout of Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Dyadobacter. HHS 11T possessed 96 and 95 % 16S rRNA gene sequence similarity with respect to Dyadobacter crusticola and Dyadobacter fermentans, respectively. Furthermore, strain HHS 11T differs from D. crusticola and D. fermentans in a number of phenotypic characteristics. These data suggest that strain HHS 11T represents a novel species of the genus Dyadobacter, for which the name Dyadobacter hamtensis sp. nov. is proposed. The type strain is HHS 11T (=JCM 12919T=MTCC 7023T).

Algoriphagus locisalis sp. nov., isolated from a marine solar saltern

Two Gram-negative, rod-shaped, non-motile bacterial strains, MSS-170T and MSS-171, were isolated from sea water of a marine solar saltern of the Yellow Sea, Korea, and characterized by using a polyphasic taxonomic approach. The two isolates grew optimally at 30 °C and in the presence of 2 % (w/v) NaCl. They were characterized chemotaxonomically as having MK-7 as the predominant menaquinone and major amounts of fatty acids iso-C15 : 0 and C16 : 1 ω7c and/or iso-C15 : 0 2-OH. The DNA G+C content of each of the two strains was 42 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the two strains fall within the evolutionary radiation enclosed by the genus Algoriphagus. Strains MSS-170T and MSS-171 had identical 16S rRNA gene sequences and exhibited a mean DNA–DNA relatedness level of 93 %. The two strains exhibited 16S rRNA gene sequence similarity levels of 96·4–98·9 % with respect to the type strains of recognized Algoriphagus species. DNA–DNA relatedness levels between the two strains and the type strains of six Algoriphagus species were less than 35 %. On the basis of phenotypic data and phylogenetic and genetic distinctiveness, strains MSS-170T and MSS-171 were classified in the genus Algoriphagus as members of a novel species, for which the name Algoriphagus locisalis sp. nov. is proposed. The type strain is MSS-170T (=KCTC 12310T=JCM 12597T).

Algoriphagus antarcticus sp. nov., a novel psychrophile from microbial mats in Antarctic lakes

A taxonomic study was performed on six strains isolated from microbial mats of lakes Reid, Fryxell and Ace in Antarctica. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains belonged to the family 'Flexibacteraceae' and were closely related to the recently described genera Algoriphagus and Hongiella. The isolates were Gram-negative, chemoheterotrophic, aerobic, psychrophilic, orange-red-pigmented bacteria and their DNA G+C content ranged from 39.9 to 41.0 mol%. Whole-cell fatty acid profiles included mainly branched fatty acids and summed feature 3, comprising 15 : 0 iso 2OH, 16 : 1omega7c or both. On the basis of genotypic, phenotypic, chemotaxonomic and phylogenetic results, the novel strains were classified as Algoriphagus antarcticus sp. nov. The type strain is LMG 21980(T) (=DSM 15986(T)=R-10710(T)).

Dyadobacter crusticola sp. nov., from biological soil crusts in the Colorado Plateau, USA, and an emended description of the genus Dyadobacter Chelius and Triplett 2000

Bacterial strain CP183-8T was isolated from biological soil crusts collected in the Colorado Plateau, USA. Cells of this strain were aerobic, non-motile, Gram-negative, psychrotolerant and formed beaded chains in the stationary growth phase. They contained C16 : 1 ω5c and C16 : 1 ω7c as major fatty acids. 16S rRNA gene sequence analysis assigned the strain to the genus Dyadobacter. However, it shared a sequence similarity of only 95·88 % with the type strain of Dyadobacter fermentans, NS114T. Because it also exhibited a significant number of phenotypic and chemotaxonomic differences from D. fermentans, it is described as a novel second species in the genus Dyadobacter, with the name Dyadobacter crusticola sp. nov. The type strain is CP183-8T (=DSM 16708T=ATCC BAA-1036T).

Roseivirga ehrenbergii gen. nov., sp. nov., a novel marine bacterium of the phylum 'Bacteroidetes', isolated from the green alga Ulva fenestrata

The taxonomic position of a novel marine bacterium isolated from the green alga Ulva fenestrata collected in the Sea of Japan was established. Cells of the strain studied, designated KMM 6017T, were strictly aerobic, heterotrophic, pink-pigmented, non-motile by gliding, Gram-negative and oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive. 16S rRNA gene sequence analysis indicated that the strain occupied a distinct lineage within the phylum 'Bacteroidetes' and formed a cluster with [Flexibacter] tractuosus and Reichenbachia agariperforans. The G+C content of the DNA of KMM 6017T was 40.2 mol%. The major respiratory quinone was MK-7. The predominant fatty acids were i15 : 1, i15 : 0 and i17 : 0 3-OH (34.2, 24 and 7.7 %, respectively). On the basis of phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, the novel bacterium was assigned to the genus Roseivirga gen. nov., as Roseivirga ehrenbergii gen. nov., sp. nov. The type strain is KMM 6017T (=KCTC 12282T=LMG 22567T).

Adhaeribacter aquaticus gen. nov., sp. nov., a Gram-negative isolate from a potable water biofilm

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.

Marinicola seohaensis gen. nov., sp. nov., isolated from sea water of the Yellow Sea, Korea

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.

Algoriphagus yeomjeoni sp. nov., isolated from a marine solar saltern in the Yellow Sea, Korea

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.