Hymenobacter endophyticus sp. nov., isolated from wheat leaf tissue

A bacterium, designated strain ZK17L-C2T, was isolated from the leaf tissues of wheat (Triticum aestivum) collected in Chengdu, Sichuan Province, PR China. It is aerobic, non-motile, Gram-negative, rod-shaped and red-to-pink in colour. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZK17L-C2T belonged to the genus Hymenobacter and was most closely related to Hymenobacter rigui KCTC 12533T (98.68 %) and Hymenobacter metallilatus 9PBR-2T (98.19 %). Digital DNA-DNA hybridization (dDDH) values between strain ZK17L-C2T and these two type strains were 26.6 and 26.5 %, and average nucleotide identity (ANI) values were 84.9 and 84.8 %, respectively; these values are lower than the proposed and generally accepted species boundaries for dDDH and ANI. The genomic DNA G+C content of strain ZK17L-C2T was 59.4 mol%. It can grow at pH 5.5-7.5 and 15-30 °C, which is different from the closely related type strains. The major fatty acids of strain ZK17L-C2T were iso-C15 : 0, C16 : 0 and C18 : 0. Overall, the results from biochemical, chemical taxonomy and phylogenetic analyses indicate that strain ZK17L-C2T (=CGMCC 1.19373T=KCTC 92184 T) represents a new species of the genus Hymenobacter, for which the name Hymenobacter endophyticus sp. nov. is proposed.

Hymenobacter canadensis sp. nov., isolated from freshwater of the pond in Cambridge Bay, Canada

A Gram-stain-negative, aerobic, reddish-coloured, rod-shaped and non-motile strain PAMC 29467^T, was isolated from freshwater of the pond in Cambridge Bay, Canada. Strain PAMC 29467^T was closely related to Hymenobacter yonginensis (98.1 % 16S rRNA gene similarity). Genomic relatedness analyses showed that strain PAMC 29467^T is distinguishable from H. yonginensis based on average nucleotide identity (91.3 %) and digital DNA-DNA hybridization values (39.3 %). The major fatty acids (>10 %) of strain PAMC 29467^T were summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c), C_15 : 0 iso, C_16 : 1  ω5c and summed feature 4 (C_17 : 1 iso l and/or anteiso B). The major respiratory quinone was menaquinone-7. The genomic DNA G+C content was 61.5 mol%. Strain PAMC 29467^T was separated from the type species in the genus Hymenobacter by its distinct phylogenetic position and some physiological characteristics. As a result, a novel species is proposed, with the name Hymenobacter canadensis sp. nov. (type strain, PAMC 29467^T=KCTC 92787^T=JCM 35843^T).

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.

Hymenobacter humicola sp. nov., isolated from soils in Antarctica

A set of three psychrotrophic bacterial strains was isolated from different soil samples collected at the deglaciated northern part of James Ross Island (Antarctica) in 2014. All isolates were rod-shaped, Gram-stain-negative, non-motile, catalase-positive and oxidase-negative, and produced moderately slimy red-pink pigmented colonies on Reasoner's 2A (R2A) agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, whole-genome sequencing, automated ribotyping, MALDI-TOF MS, chemotaxonomy methods and extensive biotyping using conventional tests and commercial identification kits was applied to the isolates in order to clarify their taxonomic position. Phylogenetic analysis based on the 16S rRNA gene showed that all isolates belonged to the genus Hymenobacter with the closest relative being Hymenobacter aerophilus DSM 13606^T, exhibiting 98.5 % 16S rRNA gene pairwise similarity to the reference isolate P6312^T. Average nucleotide identity values calculated from the whole-genome sequencing data proved that P6312^T represents a distinct Hymenobacter species. The major components of the cellular fatty acid composition were summed feature 3 (C_16 : 1 ω7c/C_16 : 1 ω6c), C_16 : 1 ω5c, summed feature 4 (C_17 : 1 anteiso B/iso I), C_15 : 0 anteiso and C_15 : 0 iso. The menaquinone system of strain P6312^T contained MK-7 as the major respiratory quinone. The predominant polar lipids were phosphatidylethanolamine and an unidentified phospholipid. Moderate to minor amounts of three unidentified polar lipids, four unidentified aminophospholipids, one unidentified glycolipid and one unidentified phospholipid were also present. Based on the obtained results, we propose a novel species for which the name Hymenobacterhumicola sp. nov. is suggested, with the type strain P6312^T (=CCM 8763^T=LMG 30612^T).

What color should glacier algae be? An ecological role for red carbon in the cryosphere

Red-colored secondary pigments in glacier algae play an adaptive role in melting snow and ice. We advance this hypothesis using a model of color-based absorption of irradiance, an experiment with colored particles in snow, and the natural history of glacier algae. Carotenoids and phenols-astaxanthin in snow-algae and purpurogallin in ice-algae-shield photosynthetic apparatus by absorbing overabundant visible wavelengths, then dissipating the excess radiant energy as heat. This heat melts proximal ice crystals, providing liquid-water in a 0°C environment and freeing up nutrients bound in frozen water. We show that purple-colored particles transfer 87%-89% of solar energy absorbed by black particles. However, red-colored particles transfer nearly as much (85%-87%) by absorbing peak solar wavelengths and reflecting the visible wavelengths most absorbed by nearby ice and snow crystals; this latter process may reduce potential cellular overheating when snow insulates cells. Blue and green particles transfer only 80%-82% of black particle absorption. In the experiment, red-colored particles melted 87% as much snow as black particles, while blue particles melted 77%. Green-colored snow-algae naturally occupy saturated snow where water is non-limiting; red-colored snow-algae occupy drier, water-limited snow. In addition to increasing melt, we suggest that esterified astaxanthin in snow-alga cells increases hydrophobicity to remain surficial.

Hymenobacter bucti sp. nov., isolated from subsurface sandstone sediment

A Gram-reaction-negative, strictly aerobic, non-motile, non-spore-forming bacterial strain, designated DK6-66^T, was isolated from subsurface sandstone sediment located in the Qilian Mountains in Qinghai Province, Northwest China. Strain DK6-66^T was found to grow optimally at pH 7.0 and 22 °C. The 16S rRNA gene sequence analysis indicated that strain DK6-66^T belonged to the genus Hymenobacter and clustered with the type strain of Hymenobacter arcticus, with which it exhibited a 16S rRNA gene sequence similarity value of 98.2 %. The DNA G+C content was 60.4 mol%. The major respiratory quinone was MK-7 and the major polar lipid was phosphatidylethanolamine. The major fatty acids were C16 : 1ω7c and/or C16 : 1ω6c, anteiso-C17 : 1 B and/or iso-C17 : 1 I, iso-C15 : 0, anteiso-C15 : 0 and C16 : 1ω5c. On the basis of phylogenetic and phenotypic data, strain DK6-66^T was classified in the genus Hymenobacter as a member of a novel species, for which the name Hymenobacterbucti sp. nov. is proposed. The type strain is DK6-66^T (=CGMCC 1.15795^T=KCTC 52629^T).

Hymenobacter defluvii sp. nov., isolated from wastewater of an acidic water neutralization facility

A non-motile, pink-coloured and rod-shaped bacterium, designated strain POA9^T, was isolated from a wastewater treatment facility, Republic of Korea. Cells were Gram-reaction-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were C16 : 1ω5c, iso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and anteiso-C15 : 0. The strain contained MK-7 as the only isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The DNA G+C content was 57 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain POA9^T forms a distinct evolutionary lineage within the radiation enclosing the members of the genus Hymenobacter, sharing the highest similarity with Hymenobacter actinosclerus CCUG 39621^T (95.5 % sequence similarity) followed by Hymenobacterseoulensis 16F7G^T (95.5 %), Hymenobactertibetensis XTM003^T (95.4 %), Hymenobacterrutilus K2-33028^T (95.4 %) and Hymenobacter psychrotolerans Tibet-IIU11^T (94.9 %). A number of phenotypic characteristics distinguished strain POA9^T from the related members of the genus Hymenobacter. On the basis of the evidence presented in this study, a novel species, Hymenobacter defluvii sp. nov., is proposed for strain POA9^T (=KCTC 52270^T=JCM 31658^T).

Hymenobacter tenuis sp. nov., isolated from wastewater of an acidic water neutralization facility

A non-motile, red-pink-coloured, rod-shaped bacterium, designated strain POB6T, was isolated from a wastewater treatment facility, Republic of Korea. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, C16 : 1ω5c, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The strain contained menaquinone MK-7 as the only isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The DNA G+C content was 61 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain POB6T forms a distinct evolutionary lineage within the radiation enclosing the members of the genus Hymenobacter, sharing the highest similarity with Hymenobacterrigui WPCP131T (97.5 %) followed by Hymenobacter xinjiangensis X2-1gT (97.2 %), Hymenobacter perfusus A1-12T (97.2 %) and Hymenobacter gelipurpurascens Txg-1T (97.1 %). A number of phenotypic characteristics distinguished strain POB6T from related members of the genus Hymenobacter. On the basis of the evidence presented in this study, a novel species, Hymenobacter tenuis sp. nov., is proposed, with POB6T (=KCTC 52271T=JCM 31659T) as the type strain.

Arcticibacterium luteifluviistationis gen. nov., sp. nov., isolated from Arctic seawater

A Gram-staining-negative, aerobic, non-motile and yellow-pigmented bacterium, designated strain SM1504T, was isolated from Arctic seawater. It hydrolysed aesculin and gelatin but did not reduce nitrate to nitrite. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain SM1504T constituted a distinct phylogenetic line within the family Cytophagaceae and was closely related to species of the genera Lacihabitans, Emticicia, Fluviimonas and Leadbetterella, with respect to which low sequence similarities between 88.9 and 91.6 % were observed. The major fatty acids of strain SM1504T were summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 0 2-OH) and iso-C15 : 0. The predominant polar lipids of strain SM1504T were phosphatidylethanolamine and one unidentified lipid. The only respiratory quinone detected in strain SM1504T was MK7. The DNA G+C content of strain SM1504T was 40.8 mol%. On the basis of the phylogenetic, chemotaxonomic and phenotypic characterization in this study, strain SM1504T is considered to represent a novel species in a new genus of the family Cytophagaceae, for which the name Arcticibacterium luteifluviistationis gen. nov., sp. nov. is proposed. The type strain is SM1504T (=KCTC 42716T=CCTCC AB 2015348T).

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)).

Hymenobacter wooponensis sp. nov., isolated from wetland freshwater

A non-motile and rod-shaped bacterium, designated strain WM78T, was isolated from freshwater collected from the Woopo wetland (Republic of Korea). Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-negative. The major fatty acids were iso-C15:0, anteiso-C15:0, C16:1ω7c and/or C16:1ω6c and iso-C17:1 I and/or anteiso-C17:1 B. The strain contained MK-7 as the major isoprenoid quinone, phosphatidylethanolamine as the major polar lipid and sym-homospermidine as the major polyamine. The genomic DNA G+C content was 62 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain WM78T forms evolutionary lineage within the radiation comprising members of the genus Hymenobacter with Hymenobacter gelipurpurascens Txg1T (97.7 % sequence similarity) as its nearest neighbour. A number of phenotypic characteristics distinguished strain WM78T from related members of the genus Hymenobacter. The evidence presented in this study support the designation of strain WM78T as a representative of a novel species in the genus Hymenobacter for which the name Hymenbactor wooponensis sp. nov. is proposed. The type strain is WM78T ( = KCTC 32528T = JCM 19491T).

Hymenobacter roseus sp. nov., isolated from sand

Strain JC245T was isolated from a sand sample, and appeared as dark pink colonies on agar plates with cells staining Gram-negative. Catalase and oxidase activities were positive. Casein was hydrolysed while chitin, gelatin and starch were not. Major (>5 %) fatty acids were iso-C15 : 0, iso-C15 : 0 3-OH, C16 : 1ω5c, C16 : 1ω6c/C16 : 1ω7c, anteiso-C17 : 1 B/iso-C17 : 1 I and iso-C17 : 0 3-OH. Strain JC245T contained phosphatidylethanolamine and two unidentified lipids as the major polar lipids, with minor amounts of four unidentified lipids and an unidentified amino lipid. Bacterial hopane derivatives and adenosylhopane were the major hopanoids. Hydroxyflexixanthin was identified as one of the major carotenoids of strain JC245T along with five unidentified carotenoids. The genomic DNA G+C content was 52.5 mol%. 16S rRNA gene sequence comparisons indicated that strain JC245T represents a member of the genus Hymenobacter within the family Cytophagaceae of the phylum Bacteroidetes . Strain JC245T shared the highest 16S rRNA gene sequence similarity with Hymenobacter roseosalivarius AA-718T (98.3 %) and other members of the genus Hymenobacter (<95.1 %). However, strain JC245T showed 21±2 % relatedness (based on DNA–DNA hybridization) with H. roseosalivarius DSM 11622T. Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strain JC245T as a representative of a novel species in the genus Hymenobacter , for which the name Hymenobacter roseus sp. nov. is proposed. The type strain is JC245T ( = KCTC 42090T = LMG 28260T).