Pontibacter liquoris sp. nov. and Pontibacter vulgaris sp. nov., two novel bacteria isolated from the pit mud of Chinese liquor.

Two pink-pigmented bacterial strains, designated NBU2971T and NBU2972T, were isolated from the pit mud of a Chinese liquor. Phylogenetic analyses based on 16S rRNA gene sequences suggested that strains NBU2971T and NBU2972T formed a distinct lineage within the family Hymenobacteraceae and were closely related to members of the genus Pontibacter. 16S rRNA gene sequences revealed that strain NBU2971T showed highest similarity of 97.9 % to Pontibacter arcticus 2b14T, and strain NBU2972T showed the highest similarity of 96.9 % to Pontibacter deserti JC215T. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two novel strains were 95.2, 73.8 and 19.6 %, respectively, suggesting that they represent different species. The ANI and dDDH values between two novel strains and related species of genus Pontibacter were well below the threshold limit for prokaryotic species delineation. The genomic DNA G+C contents of strains NBU2971T and NBU2972T were 51.3 and 44.5 mol%, respectively. The major cellular fatty acids of the two novel strains were iso-C15 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The major polar lipid of both novel strains was phosphatidylethanolamine. The only respiratory quinone was MK-7. Combining results of phenotypic, chemotaxonomic and genotypic data, strains NBU2971T and NBU2972T are considered to be two representatives in the genus Pontibacter, which the name Pontibacter liquoris sp. nov. and Pontibacter vulgaris sp. nov. are proposed. The type strains of the new species are NBU2971T (=KCTC 82916T=MCCC 1K06395T) and NBU2972T (=KCTC 82917T=MCCC 1K06396T), respectively.

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 CY22T, CY357, LJ419T, LJ53, CY399T 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 (CY22T/CY357, LJ419T/LJ53 and CY399T/CY107) were closely related to members of the genus Dyadobacter and clustered tightly with two species with validly published names, Dyadobacter alkalitolerans 12116T and Dyadobacter psychrophilus BZ26T. 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-C15 : 0 and summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c). MK-7 was the only respiratory quinone, and phosphatidylethanolamine was the predominant polar lipid for strains CY22T, LJ419T and CY399T. 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 CY22T (= GDMCC 1.3045T = KCTC 92299T), LJ419T (= GDMCC 1.2872T = JCM 33794T) and CY399T (= GDMCC 1.3052T = KCTC 92306T), respectively.

Hymenobacter terricola sp. nov., isolated from Antarctic soil.

Strain 3F2T was isolated from a soil sample obtained from the surface of Deception Island, Antarctica. The isolate was a Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, and its colonies were red to pink in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 3F2T belonged to the genus Hymenobacter, family Hymenobacteraceae and was most closely related to Hymenobacter sedentarius DG5BT (97.0% sequence similarity), Hymenobacter soli PB17T (96.9%), Hymenobacter terrae DG7AT (96.8%) and Hymenobacter rufus S1-2-2-6T (96.5%). Growth occurred at 4-20 °C (optimum, 10 °C), up to 1.0 % (w/v) NaCl (optimum, 0%) and pH 6.0-8.0 (optimum, pH 7.0). The chemotaxonomic characteristics of strain 3F2T, which had MK-7 as its predominant menaquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), iso-C15:0, anteiso-C15:0 and C16:1 ω5c as its major fatty acids, were consistent with classification in the genus Hymenobacter. The polar lipid profile of strain 3F2T comprised phosphatidylethanolamine, two unidentified aminolipids, two unidentified aminophospholipids and three unidentified polar lipids. The genome of strain 3F2T was 6.56 Mbp with a G+C content of 61.5 mol%. Average nucleotide identity (ANI) values between 3F2T and the other species of the genus Hymenobacter were found to be low (ANIm <87.0%, ANIb <82.0% and OrthoANIu <83.0%). Furthermore, digital DNA-DNA hybridization and average amino acid identity values between strain 3F2T and the closely related species ranged from 20.0 to 26.3% and from 64.0 to 81.1 %, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain 3F2T represents a novel species within the genus Hymenobacter, for which the name Hymenobacter terricola sp. nov. is proposed. The type strain is 3F2T (=KCTC 72468T=CGMCC 1.13716T).

Dyadobacter sandarakinus sp. nov., isolated from Arctic tundra soil, and emended descriptions of Dyadobacter alkalitolerans, Dyadobacter koreensis and Dyadobacter psychrophilus.

Strain Q3-56T, isolated from Arctic tundra soil, was found to be a Gram-stain-negative, yellow-pigmented, oxidase- and catalase-positive, non-motile, non-spore-forming, rod-shaped and aerobic bacterium. Strain Q3-56T grew optimally at pH 7.0 and 28 °C. The strain could tolerate up to 1 % (w/v) NaCl with optimum growth in the absence of NaCl. The strain was not sensitive to oxacillin and ceftazidime. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Q3-56T belonged to the genus Dyadobacter. Strain Q3-56T showed the highest sequence similarities to Dyadobacter luticola T17T (96.58 %), Dyadobacter ginsengisoli Gsoil 043T (96.50 %), Dyadobacter flavalbus NS28T (96.43 %) and Dyadobacter bucti QTA69T (96.43 %). The predominant respiratory isoprenoid quinone was identified as MK-7, The polar lipid profile of strain Q3-56T was found to contain one phosphatidylethanolamine, three unidentified aminolipids, three unidentified lipids and one unidentified phospholipid. The G+C content of the genomic DNA was determined to be 49.1 mol%. The main fatty acids were summed feature 3 (comprising C16 : 1 ω7c/C16 : 1 ω6c), iso-C15 : 0, C16 : 1 ω5c and iso-C16 : 1 3-OH. On the basis of the evidence presented in this study, a novel species of the genus Dyadobacter, Dyadobacter sandarakinus sp. nov., is proposed, with the type strain Q3-56T (=CCTCC AB 2019271T=KCTC 72739T). Emended descriptions of Dyadobacter alkalitolerans, Dyadobacter koreensis and Dyadobacter psychrophilus are also provided.

Dyadobacter subterraneus sp. nov., isolated from hydrocarbon-polluted groundwater from an oil refinery in Hungary.

A Gram-stain-negative, aerobic, non-spore-forming, rod-shaped bacterial strain (UP-52T) was isolated from hydrocarbon-polluted groundwater located near an oil refinery in Tiszaujvaros, Hungary. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Dyadobacter in the family Cytophagaceae. Its closely related species are Dyadobacter frigoris (98.00 %), Dyadobacter koreensis (97.64 %), Dyadobacter psychrophilus (97.57 %), Dyadobacter ginsengisoli (97.56 %) and Dyadobacter psychrotolerans (97.20 %). The predominant fatty acids are summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω7c/C16 : 1 ω6c), C15 : 0 iso, C16 : 1 ω5c and C17 : 0 iso 3OH. The predominant respiratory quinone detected in strain UP-52T is quinone MK-7. The dominant polar lipids are glycolipid, phosphoaminolipid, phospholipid and aminolipid. The DNA G+C content is 40.0 mol%. Flexirubin-type pigment was present. Based on these phenotypic, chemotaxonomic and phylogenetic results, UP-52T represents a novel species of the genus Dyadobacter, for which the name Dyadobacter subterraneus sp. nov. is proposed. The type strain is UP-52T (=NCAIM B.02653T=CCM 9030T).

Assessing the efficacy of eDNA metabarcoding for measuring microbial biodiversity within forest ecosystems.

We investigated the nascent application and efficacy of sampling and sequencing environmental DNA (eDNA) in terrestrial environments using rainwater that filters through the forest canopy and understory vegetation (i.e., throughfall). We demonstrate the utility and potential of this method for measuring microbial communities and forest biodiversity. We collected pure rainwater (open sky) and throughfall, successfully extracted DNA, and generated over 5000 unique amplicon sequence variants. We found that several taxa including Mycoplasma sp., Spirosoma sp., Roseomonas sp., and Lactococcus sp. were present only in throughfall samples. Spiroplasma sp., Methylobacterium sp., Massilia sp., Pantoea sp., and Sphingomonas sp. were found in both types of samples, but more abundantly in throughfall than in rainwater. Throughfall samples contained Gammaproteobacteria that have been previously found to be plant-associated, and may contribute to important functional roles. We illustrate how this novel method can be used for measuring microbial biodiversity in forest ecosystems, foreshadowing the utility for quantifying both prokaryotic and eukaryotic lifeforms. Leveraging these methods will enhance our ability to detect extant species, describe new species, and improve our overall understanding of ecological community dynamics in forest ecosystems.

Spirosoma endbachense sp. nov., isolated from a natural salt meadow.

A Gram-stain-negative bacterium, designated I-24T, was isolated from soil of a natural salt meadow. Strain I-24T was aerobic, non-motile, rod-shaped, catalase-positive, oxidase-positive and grew optimally at pH 7 and 25 °C. Comparative 16S rRNA gene analysis indicated that strain I-24T has closest similarities to Spirosoma agri KCTC 52727T (95.9 %) and Spirosoma terrae KCTC 52035T (95.5 %). Strain I-24T contained summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c) and C16 : 1 ω5c as the major fatty acids, the predominant respiratory quinone was menaquinone MK-7, and the major polar lipids were phosphatidylethanolamine as well as an unidentified phosphoaminolipid. The draft genome of strain I-24T consists of 10 326 072 base pairs with 9153 predicted coding sequences and a G+C content of 47.7 mol%. Clear distinctions between strain I-24T and S. agri KCTC 52727T or S. terrae KCTC 52035T were shown in the pairwise average nucleotide identity results with values of 76.71 and 74.01 %, respectively. Moreover, the digital DNA-DNA relatedness values to these strains were 20.8 and 19.0 %. Based on its phenotypic, genotypic and chemotaxonomic characteristics, strain I-24T represents a novel species of the genus Spirosoma, for which the name Spirosoma endbachense sp. nov. is proposed. The type strain is I-24T (DSM 111055T=KCTC 72613T).

Spirosoma aureum sp. nov., and Hymenobacter russus sp. nov., radiation-resistant bacteria in Cytophagales order isolated from soil.

A Gram-stain-negative, aerobic, nonmotile, yellow-colored strain BT328T and Gram-stain-negative, aerobic, non-motile, red-colored strain BT18T were isolated from the soil collected in Korea. Phylogenetic analyses based on 16S rRNA gene sequence revealed that strain BT328T formed a distinct lineage within the family Spirosomaceae (order Cytophagales, class Cytophagia) and was most closely related to a member of the genus Spirosoma, Spirosoma terrae 15J9-4T (95.9% 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C, pH 7.0 and in the absence of NaCl. The predominant cellular fatty acids were summed feature 3 (C16:1 ω6c/C16:1 ω7c) and C16:1 ω5c. The major respiratory quinone was MK-7. The major polar lipid was phosphatidylethanolamine. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BT18T formed a distinct lineage within the family Hymenobacteraceae (order Cytophagales, class Cytophagia, phylum Bacteroidetes) and was most closely related to members of the genus Hymenobacter, Hymenobacter knuensis 16F7C-2T (97.0% 16S rRNA gene sequence similarity). Optimal growth occurred at 25 °C and pH 7.0 without NaCl. The major fatty acids were iso-C15:0 and anteiso-C15:0. The major menaquinone was MK-7. The major polar lipid was phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strains BT328T and BT18T represents a novel bacterial species within the genus Spirosoma and Hymenobacter, respectively. For which the name Spirosoma aureum and Hymenobacter russus is proposed. The type strain of S. aureum is BT328T (=KCTC 72365T = NBRC 114506T) and the type strain of H. russus is BT18T (=KCTC 62610T = NBRC 114380T).

Spirosoma telluris sp. nov. and Spirosoma arboris sp. nov. isolated from soil and tree bark, respectively.

Two novel strains (HMF3257T and HMF4905T), isolated from freshwater and bark samples, were investigated to determine their relationships within and between species of the genus Spirosoma by using a polyphasic approach. They were aerobic, Gram-stain-negative, non-motile and rod-shaped bacteria. The major fatty acids (>10%) in both strains were identified as summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 1 ω5c, while strains HMF3257T and HMF4905T contained a moderately high amount of C16 : 0 and iso-C15 : 0, respectively. The predominant respiratory quinone was MK-7 for both strains. In addition to phosphatidylethanolamine and one unidentified glycolipid, the polar lipid profile of strain HMF3257T consisted of three unidentified aminophospholipids, one unidentified aminolipid and two unidentified polar lipids, and that of strain HMF4905T consisted of one unidentified aminophospholipid, two unidentified aminolipids and three unidentified polar lipids. The DNA G+C contents of strains HMF3257T and HMF4905T were 47.2 and 46.4 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains HMF3257T and HMF4905T are closely related to Spirosoma migulaei 15J9-8T (97.0 % sequence similarity), while sharing 97.4 % sequence similarity with each other. The average nucleotide identity value between strains HMF3257T and HMF4905T was 81.1 %, and the digital DNA-DNA hybridization value between these two strains was 24.4 %. Based on the above data, strains HMF3257T and HMF4905T represent two novel members within the genus Spirosoma, for which the names Spirosoma telluris sp. nov. and Spirosoma arboris sp. nov. are proposed, respectively. The type strain of S. telluris is HMF3257T (=KCTC 62463T=NBRC 112670T) and type strain of S. arboris is HMF4905T (=KCTC 72779T=NBRC 114270T).

Gemmobacter aquarius sp. nov., Runella rosea sp. nov. and Flavobacterium fluviale sp. nov., isolated from the Namhangang River system.

Three bacterial strains, namely HYN0069T, HYN0085T and HYN0086T, were isolated from freshwater samples taken from the Namhangan River system in Korea. 16S rRNA gene sequence similarities and phylogenetic tree topologies indicated that the three strains belonged to the genera Gemmobacter, Runella and Flavobacterium by showing the highest sequence similarities with Gemmobacter straminiformis (98.4 %), Runella aurantiaca (98.3 %) and Flavobacterium chungangense (98.1 %). No bacterial species with validly published names showed 98.7 % or higher sequence similarity with the novel isolates. The average nucleotide identities between the genome sequences of the three new isolates and the three closest neighbours were 80.2-92.0 %, all below the threshold for bacterial species delineation (95-96 %). Many biochemical and physiological features also discriminated the isolates from previously known species of the genera Gemmobacter, Runella and Flavobacterium. Based on the phylogenetic and phenotypic data presented in this study, we suggest three novel species with the following names: Gemmobacter aquarius sp. nov. (type strain HYN0069T=KACC 19488T=NBRC 113115T), Runella rosea sp. nov. (type strain HYN0085T=KACC 19490T=NBRC 113116T) and Flavobacterium fluviale sp. nov. (type strain HYN0086T=KACC 19489T=NBRC 113117T).

Hymenobacter artigasi sp. nov., isolated from air sampling in maritime Antarctica.

A rod-shaped and Gram-stain-negative bacterial strain, 1BT, was isolated from an air sample collected at King George Island, maritime Antarctica. Strain 1BT is strictly aerobic, psychrophilic, catalase-positive, oxidase-positive and non-motile. Growth of strain 1BT is observed at 0-20 °C (optimum, 10 °C), pH 6.0-8.0 (optimum, pH 8.0) and in the presence of 0-1.0% NaCl (optimum, 0.5 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequences places strain 1BT within the genus Hymenobacter and shows the highest similarity to Hymenobacter antarcticus VUG-A42aaT (97.5 %). The predominant menaquinone of strain 1BT is MK-7 and the major fatty acids (>10 %) comprise summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 32.5 %), iso-C15 : 0 (17.6 %) and anteiso C15 : 0 (12.3 %). The polar lipid profile consists of the major compounds phosphatidylethanolamine, phosphatidylserine, two unidentified aminolipids and one unidentified phospholipid. The DNA G+C content based on the draft genome sequence is 61.2 mol%. Based on the data from the current polyphasic study, 1BT represents a novel species of the genus Hymenobacter, for which the name Hymenobacter artigasi sp. nov. is suggested. The type strain is 1BT (=CCM 8970T=CGMCC 1.16843T).

Hymenobacter fodinae sp. nov. and Hymenobacter metallicola sp. nov., isolated from abandoned lead-zinc mine.

Two novel strains, designated 92R-1T and 9PBR-1T, were isolated from abandoned lead-zinc ore collected in Meizhou, Guangdong Province, PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that they fell into the genus of Hymenobacter and formed two distinct lineages. Strain 92R-1T was most closely related to Hymenobacter wooponensis JCM 19491T (98.7 %) and Hymenobacter gelipurpurascens LMG 21873T (98.5 %), while strain 9PBR-1T was most closely related to Hymenobacter chitinivorans LMG 21951T (99.0 %), Hymenobacter elongatus JCM 17223T (98.7 %) and Hymenobacter aquaticus JCM 31653T (98.1 %). Strain 92R-1Tshared average nucleotide identity values of 80.0-83.7 % and digital DNA-DNA hybridization values of 23.1-27.1 % with its closely related type strains, respectively, while strain 9PBR-1T shared corresponding values of 80.3-83.2 % and 23.6-26.7 % with its closely related type strains, respectively. The two novel strains could be clearly distinguished from their closely related type strains by enzyme activities and substrates assimilation, respectively. Both of them took iso-C15:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B) and C16:1 ω5c as major fatty acids, and showed clear differences from their closely relatives in the contents of several components. They contained menaquinone 7 as the major respiratory quinone and phosphatidylethanolamine as the dominant polar lipid. The G+C contents of strains 92R-1T and 9PBR-1T were 56.7 and 59.5 mol%, respectively. The results clearly supported that strains 92R-1T and 9PBR-1T represent two distinct novel species within the genus Hymenobacter, for which the names Hymenobacter fodinae sp. nov. (type strain 92R-1T=GDMCC 1.1493T=JCM 32697T) and Hymenobacter metallicola sp. nov. (type strain 9PBR-1T=GDMCC 1.1491T=JCM 32698T) are proposed.

Hymenobacter ginkgonis sp. nov., isolated from bark of Ginkgo biloba.

Strain HMF4947T, isolated from the bark of a ginkgo tree, was a pale-pink coloured, Gram-stain-negative, non-motile, strictly aerobic and rod-shaped bacterium. The isolate grew optimally on Reasoner's 2A agar at 30 °C, pH 7.0 and with 0 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain HMF4947T belonged to the genus Hymenobacter and was most closely related to Hymenobacter metalli A2-91T (96.9 % sequence similarity) and Hymenobacter pomorum 9-2-1-1T (96.5 %). The average nucleotide identity and estimated DNA-DNA hybridization values between strain HMF4947T and Hymenobacter arizonensis DSM 17870T were 74.3 and 20.5 %, respectively. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), iso-C15 : 0 and C16 : 1 ω5c. The predominant isoprenoid quinone was menaquinone-7. The polar lipids comprised phosphatidylethanolamine, one unidentified aminoglycolipid, three unidentified aminophospholipids, one unidentified phospholipid, three unidentified aminolipids, two unidentified glycolipids and three unidentified polar lipids. The genomic DNA G+C content was 59.3 mol%. Thus, based on phylogenetic, phenotypic and chemotaxonomic data, strain HMF4947T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter ginkgonis sp. nov. is proposed. The type strain of the species is strain HMF4947T (=KCTC 72780T=NBRC 114271T).

Larkinella punicea sp. nov., isolated from manganese mine soil.

Strain ZZJ9T is a Gram-stain-negative, rod-shaped, aerobic bacterium isolated from manganese mine soil. Strain ZZJ9T showed the highest 16S rRNA gene sequence similarities with Larkinella rosea 15J16-1T3AT (97.1%), Larkinella terrae 15J8-8T (97.0%), Larkinella knui 15J6-3T6T (96.8%), and Larkinella ripae 15J11-1T (95.3%). The genome size of strain ZZJ9T was 8.01 Mb and the DNA G+C content was 51.8 mol%. ANI values among strain ZZJ9T and Larkinella rosea 52004 T, Larkinella knui KCTC 42998T, and Larkinella terrae 52001T were 80.5%, 82.7%, and 80.5%, respectively. dDDH values among strain ZZJ9T and Larkinella rosea 52004T, Larkinella knui KCTC 42998T, and Larkinella terrae 52001T were 23.5%, 26.0%, and 23.6%, respectively. Furthermore, the genome of strain ZZJ9T contained 6302 predicted protein-coding genes and 3114 (49%) of them had classificatory functions. The major quinone of strain ZZJ9T was menaquinone-7 and the main cellular fatty acids were C16:1ω5c (39.5%), iso-C15:0 (25.6%), and iso-C17:0 3OH (11.5%). The polar lipids of strain ZZJ9T were phosphatidylethanolamine, unidentified lipid, and two unidentified aminolipids. Based on the results of phylogenetic, genome, phenotypic, and chemotaxonomic analytical, strain ZZJ9T represents a novel species of the genus Larkinella, for which the name Larkinella punicea sp. Nov. is proposed. The type strain is ZZJ9T (= KCTC 62876T = CCTCC AB 2018215T).

Aquirufa ecclesiirivi sp. nov. and Aquirufa beregesia sp. nov., isolated from a small creek and classification of Allopseudarcicella aquatilis as a later heterotypic synonym of Aquirufa nivalisilvae.

Two bacterial strains, 50A-KIRBAT and 50C-KIRBAT, were isolated from the same freshwater creek located near Salzburg, Austria. They showed 16S rRNA gene sequence similarities to Aquirufa nivalisilvae of 100 and 99.9 %, respectively. A genome-based phylogenetic reconstruction with amino acid sequences of 119 single-copy genes suggested that the new strains represent two new species of the genus Aquirufa. Pairwise calculated whole-genome average nucleotide identity (gANI) values ranging from 85.4 to 87.5 % confirmed this conclusion. Phenotypic, chemotaxonomic and genomic traits were investigated. Like strains of other Aquirufa species, 50A-KIRBAT and 50C-KIRBAT grew aerobically and chemoorganotrophically, were rod-shaped, red-pigmented and motile, most likely by gliding. They could be distinguished by slight differences in the chemotaxonomic features. We propose to establish for strain 50A-KIRBAT (=CIP 111735T=LMG 31080T) as type strain the name Aquirufa ecclesiirivi and for strain 50C-KIRBAT (=CIP 111736T=LMG 31501T) as type strain the name Aquirufa beregesia. Furthermore, the relationship between the type strains of Aquirufa nivalisilvae (59G-WUEMPELT) and Allopseudarcicella aquatilis (HME7025T) was investigated. Results of polyphasic analyses, especially a gANI value of 97.6 %, as well as the genome-based phylogenetic reconstruction, suggested that Allopseudarcicella aquatilis is a heterotypic synonym of Aquirufa nivalisilvae. According to rule 24b of the International Code of Nomenclature of Prokaryotes we propose to classify strain HME7025 as Aquirufa nivalisilvae and provide an emended description for the latter.

Hymenobacter polaris sp. nov., a psychrotolerant bacterium isolated from an Arctic station.

A pink-pigmented, non-motile, Gram-stain-negative, rod-shaped bacterium, designated RP-2-7T, was obtained from soil sampled at the Arctic station, Spitsbergen, Svalbard, Norway. Cells were strictly aerobic, psychrotolerant, grew optimally at 15-20 °C and hydrolysed CM-cellulose. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain RP-2-7T formed a lineage within the family Hymenobacteraceae and clustered with members of the genus Hymenobacter. Its closest relative was Hymenobacter marinus KJ035T (97.6 % sequence similarity). The sequence similarities to other strains were ≤96.9 %. The principal respiratory quinone was MK-7 and the major polar lipids were phosphatidylethanolamine and an unidentified aminophospholipid. The predominant cellular fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), anteiso-C15 : 0, iso-C15 : 0, C16 : 1 ω5c and summed featured 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The DNA G+C content was 62.8 mol%. In addition, the average nucleotide identity and in silico DNA-DNA hybridization relatedness values between strain RP-2-7T and closely related strains were lower than species demarcation thresholds. Based on the resuls of genomic, chemotaxonomic, phenotypic and phylogenetic analyses, strain RP-2-7T represents novel species in the genus Hymenobacter, for which the name Hymenobacter polaris sp. nov. is proposed. The type strain is RP-2-7T (=KACC 21670T=NBRC 114391T).

Pontibacter pudoricolor sp. nov., and Pontibacter russatus sp. nov. radiation-resistant bacteria isolated from soil.

Gram-stain-negative, aerobic, non-flagellated, red-colored strains BT214T and BT326T were isolated from soil collected in Uijeongbu city, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strains BT214T and BT326T formed a distinct lineage within the family Hymenobacteraceae (order Chitinophagales, class Chitinophagia) and were most closely related to members of the genus Pontibacter, Pontibacter populi HLY7-15T (96.9% 16S rRNA gene sequence similarity) and Pontibacter amylolyticus 9-2T (96.1%), respectively. Optimal growth of two strains occurred at 25 °C, pH 7.0 and in the absence of NaCl. The predominant cellular fatty acids were summed feature 4 (iso-C17:1 I/anteiso-C17:1 B) and iso-C15:0. The major respiratory quinone of two strains was MK-7. The major polar lipid of two strains was phosphatidylethanolamine. Biochemical, chemotaxonomic and phylogenetic analyses indicated that strains BT214T and BT326T represent novel bacterial species within the genus Pontibacter, for which the names Pontibacter pudoricolor and Pontibacter russatus are proposed. The type strains of Pontibacter pudoricolor and Pontibacter russatus are BT214T and BT326T, respectively.

Hymenobacter setariae sp. nov., isolated from the ubiquitous weedy grass Setaria viridis.

A Gram-stain-negative, short-rod, aerobic, non-motile, red to pink-pigmented bacterium, designated Fur1T, was isolated from the dry spikelet clusters of a plant called Setaria viridis near Dongguk University. Phylogenetic analysis conducted based on 16S rRNA gene sequences indicated that strain Fur1T belonged to the genus Hymenobacter of the family Hymenobacteraceae. The 16S rRNA gene of Fur1T showed highest sequence similarity to those of Hymenobacter metalli KACC 17381T (97.5 %) and Hymenobacter marinus KACC 19042T (97.1 %). Growth occurred at 4-37 °C (optimum, 25-28 °C), up to 1.0 % NaCl (optimum, 0 %) and pH 5.5-9.0 (optimum, pH 6.0-7.5). The major fatty acids of strain Fur1T were identified as iso-C15 : 0, C16 : 1 ω5c, anteiso-C15 : 0, summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 4 (comprising anteiso-C17 : 1B and/or iso-C17 : 1I) as the major cellular fatty acids. The predominant respiratory quinone was identified as MK-7. The polar lipids were phosphatidylethanolamine, five unidentified aminophospholipids, two unidentified phospholipids, one unidentified glycolipid and one unidentified polar lipid. The genomic DNA G+C content based on the draft genome sequence was 58.7 mol%. DNA-DNA relatedness between strain Fur1T and its closest relative was below 70 %. Characterization based on phylogenetic, chemotaxonomic and phenotypic analyses clearly indicated that strain Fur1T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter setariae sp. nov. is proposed. The type strain is Fur1T (=KACC 19903T=NBRC=113691T).

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

A bacterial strain designated CAR-16T 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-16T represented a member of the family Cytophagaceae and formed a phylogenetic lineage in the genus Aquirufa. CAR-16T was most closely related to Aquirufa nivalisilvae 59G-WUEMPELT with a 99.7 % 16S rRNA gene sequence similarity. CAR-16T 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-16T were iso-C15 : 0, iso-C15 : 0 3-OH, C16 : 1ω5c and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c and/or iso-C15 : 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-16T was 38.8 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, CAR-16T 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-16T (=BCRC 81153T=LMG 30923T=KCTC 62869T).

Hymenobacter lutimineralis sp. nov., belonging to the family Hymenobacteraceae, isolated from zeolite.

A red-pigmented bacterial strain, designated KIGAM108T, within the family Hymenobacteraceae was isolated from zeolite in the Gampo-41 mine of the Gyeongju, Republic of Korea. This strain was a Gram-negative, strictly aerobic, non-spore forming, rod-shaped bacterium. Phylogenetic analysis of the 16S rRNA gene sequence of strain KIGAM108T found that it was related to the genus Hymenobacter, with similarities of 96.6, 96.4, 95.5, and 95.0% to H. fastidiosus VUG-A124T, H. algoricola VUG-A23aT, H. crusticola MIMBbqt21T, and H. daecheongensis DSM 21074T, respectively. Strain KIGAM108T grew in the presence of 0-0.5% (w/v) NaCl at 4-37 °C and pH 6.0-10.0. This isolate contained MK-7 as a respiratory quinone. The polar lipids of strain KIGAM108T were identified as phosphatidylethanolamine, two unidentified aminophospholipids, one unidentified phospholipid and five unidentified lipids. The major fatty acids profile showed summed feature 3 (C16:1ω6c and/or C16:1ω7c) (22.3%), anteiso-C15:0 (17.1%), C16:1ω5c (13.3%), and iso-C15:0 (11.0%). The genomic DNA G + C content was 60.0 mol%. Based on the polyphasic taxonomic data, strain KIGAM108T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter lutimineralis sp. nov. is proposed. The type strain is KIGAM108T (=KCTC 72263T =JCM 33444T).