Hymenobacter terrae sp. nov., a Bacterium Isolated from Soil

Isolation and characterization of two new species, Hymenobacter mellowenesis sp. nov. and Hymenobacter aranciens sp. nov., from soil

Strains M29T and ASUV-10-1T, which are aerobic, non-flagellated, and Gram-stain-negative, were isolated from soil samples collected in Inje (37°57'49.1"N 128°19'53.7"E) and Cheonan City (36°48'47.1"N 127°05'22.4"E), South Korea. Phylogenetic analyses based on rRNA gene sequences revealed that strains M29T and ASUV-10-1T form a distinct branch within the family Hymenobacter (order Cytophagales, class Cytophagia). Strain M29T is most closely related to Hymenobacter rubidus DG7BT with a 16 S rRNA gene sequence similarity of 97.05%. Strain ASUV-10-1T shows closest genetic similarity to Hymenobacter frigidus B1789T (96.42%), Hymenobacter jeongseonensis BT683T (95.97%), and Hymenobacter terricola 3F2TT (95.65%). The optimal growth conditions for these strains are pH 7.0, no NaCl, and a temperature of 25 °C. The dominant cellular fatty acids identified in these strains are iso-C15:0, anteiso-C15:0, and Summed Feature 3 (C16:1ω 7c / C16:1ω 6c). Both strains predominantly contain MK-7 as the respiratory quinone. The major polar lipids in strains M29T and ASUV-10-1T are phosphatidylethanolamine, aminophospholipid, and aminolipid. Based on biochemical, chemotaxonomic, and phylogenetic data, it is evident that M29T and ASUV-10-1T represent new species within the genus Hymenobacter. The new species were classified based on biochemical and chemotaxonomic characteristics. The taxonomic classification of these species was conducted following the guidelines and protocols outlined in Bergey's Manual of Systematic Bacteriology. We followed the methods for determining physiological and biochemical characteristics, as well as chemotaxonomic markers such as fatty acid profiles, quinone types, and polar lipid compositions. We also compared with the results of carbohydrate utilization and enzyme activities results [Bergey 1994]. Therefore, we propose the names Hymenobacter mellowenesis for strain M29T (= KCTC 102056T = NBRC 116578T) and Hymenobacter aranciens for strain ASUV-10-1T (= KCTC 92969T = NBRC 116575T).

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).

Description of Hymenobacter sediminicola sp. nov., isolated from contaminated sediment

A polyphasic taxonomic study was conducted on two Gram-negative, non-sporulating, non-motile bacterial strains, S2-20-2^T and S2-21-1, isolated from a contaminated freshwater sediment in China. Comparative 16S rRNA gene sequence studies revealed a clear affiliation of two strains with Bacteroidetes, which showed the highest pairwise sequence similarities with Hymenobacter duratus BT646^T (99.3%), Hymenobacter psychrotolerans Tibet-IIU11^T (99.3%), Hymenobacter kanuolensis T-3^T (97.6%), Hymenobacter swuensis DY53^T (96.9%), Hymenobacter tenuis POB6^T (96.8%), Hymenobacter seoulensis 16F7G^T (96.7%), and Hymenobacter rigui KCTC 12533^T (96.5%). The phylogenetic analysis based on 16S rRNA gene sequences showed that two strains formed a clear phylogenetic lineage with the genus Hymenobacter. Major fatty acids were identified as iso-C_15:0, anteiso-C_15:0, and summed feature 3 (C_16:1 ω6c and/or C_16:1 ω7c/t) and summed feature 4 (iso-C_17:1 I and/or anteiso-C_17:1 B). Major cellular polar lipids were identified as phosphatidylethanolamine, three unidentified aminolipids, an unidentified aminophosopholipid and an unidentified lipid. The respiratory quinone was detected as MK-7 and the genomic DNA G + C content was determined to be 57.9% (genome) for type strain S2-20-2^T and 57.7 mol% (HPLC) for strain S2-21-1. The observed ANI and dDDH values between strain S2-20-2^T and its closely related strains were 75.7-91.4% and 21.2-43.9%, respectively. Based on physiological, biochemical, genetic and genomic characteristics, we propose that strains S2-20-2^T and S2-21-1 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter sediminicola sp. nov. is proposed. The type strain is S2-20-2^T (= CGMCC 1.18734^T = JCM 35801^T).

Hymenobacter cyanobacteriorum sp. nov., isolated from a freshwater reservoir during the cyanobacterial bloom period

A Gram-negative, red-colored, and rod-shaped bacterial strain, DH14^T, was isolated from a eutrophic reservoir. The 16S rRNA gene sequence analysis showed that strain DH14^T was most closely related to Hymenobacter terrigena (98.3% similarity) and Hymenobacter terrae (98.1%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain DH14^T and its related type strains were below 82.9% and 27.2%, respectively. Strain DH14^T contained iso-C_15:0 (32.6%), anteiso-C_15:0 (14.0%), and summed feature 3 (C_16:1 ω6c and/or C_16:1 ω7c) (25.8%) as major cellular fatty acids. The main polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids, and one unidentified lipid. The respiratory quinone was menaquinone 7 (MK-7). The genomic DNA G + C content was 62.1%. These evidences support the classification of strain DH14^T as a novel species in the genus Hymenobacter, for which the name Hymenobacter cyanobacteriorum sp. nov. is proposed. The type strain is DH14^T (= KCTC 92040^T = LMG 32425^T).

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).

Hymenobacter negativus sp. nov., bacteria isolated from mountain soil collected in South Korea

Two novel Gram-negative bacterial strains BT442^T and BT584 were isolated from dry soil collected in mountains Busan and Guri, Korea during wintertime. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains BT442^T and BT584 both belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia). Strain BT442^T was closely related to Hymenobacter soli PB17^T (98.0% 16S rRNA gene similarity) and Hymenobacter terrae POA9^T (97.6%). No other recognized bacterial species showed more than 97% 16S rRNA gene sequence similarity to strains BT442^T. The genome size of strain BT442^T was 5,143,362 bp. Bacterial growth was observed at 10-30 °C (optimum 25 °C), pH 6.0-8.0 (optimum pH 6.0) in R2A agar and in the presence up to 1% NaCl. The major cellular fatty acids of strains BT442^T and BT584 were iso-C_15:0, anteiso-C_15:0 and summed feature 3 (C_16:1 ω6c / C_16:1 ω7c). In addition, their predominant respiratory quinone was MK-7. The major polar lipids of strains BT442^T and BT584 were identified to be phosphatidylethanolamine, aminophospholipid, and aminolipid. Based on the biochemical, chemotaxonomic, and phylogenetic analyses, strains BT442^T and BT584 are novel bacterial species within the genus Hymenobacter, and the proposed name is Hymenobacter negativus. The strain type of Hymenobacter negativus is BT442^T (= KCTC 72902^T = NBRC XXXX^T).

Validating biochemical features at the genome level in the Antarctic bacterium Hymenobacter sp. strain UV11

We present experimental data that complement and validate some biochemical features at the genome level in the UVC-resistant Antarctic bacterium Hymenobacter sp. UV11 strain. The genome was sequenced, assembled and annotated. It has 6 096 246 bp, a GC content of 60.6% and 5155 predicted genes. The secretome analysis, by combining in silico predictions with shotgun proteomics data, showed that UV11 strain produces extracellular proteases and carbohydrases with potential biotechnological uses. We observed the formation of outer membrane vesicles, mesosomes and carbon-storage compounds by using transmission electron microscopy. The in silico analysis of the genome revealed the presence of genes involved in the metabolism of glycogen-like molecules and starch. By HPLC-UV-Vis analysis and 1H-NMR spectra, we verified that strain UV11 produces xanthophyll-like carotenoids such as 2'-hydroxyflexixanthin, and the in silico analysis showed that this bacterium has genes involved in the biosynthesis of cathaxanthin, zeaxanthin and astaxanthin. We also found genes involved in the repair of UV-damaged DNA such as a photolyase, the nucleotide excision repair system and the production of ATP-dependent proteases that are important cellular components involved in the endurance to physiological stresses. This information will help us to better understand the ecological role played by Hymenobacter strains in the extreme Antarctic environment.

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

A bacterial strain, S1-2-2-6^T, was isolated from a soil sample collected in Jeollabuk-do province, Republic of Korea. Cells of this strain were observed to be Gram-stain-negative, short and rod-shaped, and colonies were red to pink in colour. Analysis of 16S rRNA gene sequences identified this strain as representing a member of the genus Hymenobacter in the family Cytophagaceae, with the highest levels of sequence similarity being observed in relation to Hymenobacter terrae DG7A^T (98.2 %), Hymenobacter rubidus DG7B^T (97.9 %), Hymenobacter soli PB17^T (97.7 %), and Hymenobacter daeguensis 16F3Y-2^T (97.3 %). Growth of S1-2-2-6^T was observed at 4-30 °C, pH 6-8 and in the presence of 0-0.5 % NaCl. The predominant respiratory quinone of this strain was menaquinone-7, the major fatty acids were C15 : 0 iso, C15 : 0 anteiso, and Summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), and the major polar lipid was phosphatidylethanolamine. The genomic DNA G+C content of S1-2-2-6^T was 60.7 mol%. DNA-DNA hybridization experiments with H. terrae, H. rubidus, H. soli and H. daeguensisresulted in relatedness values of 35.9 and 38.4 %, 34.2 and 30.4 %, 28.3 and 33.1 %, and 23.5 and 27.9 %, respectively. These DNA-DNA hybridization results, in addition to some differentiating phenotypic properties, clearly indicate that S1-2-2-6^T is a representative of a novel species of the genus Hymenobacter, for which the name Hymenobacter rufus sp. nov. is proposed. The type strain is S1-2-2-6^T (=KCTC 52736^T=JCM 32196^T).

Description of Hymenobacter daejeonensis sp. nov., isolated from grass soil, based on multilocus sequence analysis of the 16S rRNA gene, gyrB and tuf genes

A polyphasic taxonomic study was carried out on strains PB105^T and PB108 isolated from a grass soil in Korea. The cells of the strains were Gram-stain negative, non-spore-forming, non-motile, and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of these strains with Bacteroidetes, which showed high pairwise sequence similarities with Hymenobacter algoricola VUG-A23a^T (99.2%), Hymenobacter fastidiosus VUG-A124a^T (97.4%), and Hymenobacter daecheongensis Dae14^T (96.9%). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Hymenobacter. The major fatty acids were identified as C_15:0 iso, C_15:0 anteiso, C_16:1 ω5c, C_15:0 iso 3-OH, C_17:0 iso 3-OH, summed feature 3 (C_16:1 ω6c and/or C_16:1 ω7c/t), and summed feature 4 (C_17:1 anteiso B and/or C_17:1 iso I). The major cellular polar lipids were identified as phosphatidylethanolamine, an unidentified aminolipid, and two unidentified lipids. The respiratory quinone was identified as MK-7 and the genomic DNA G+C content was determined to be 64.5 mol% for strain PB105^T and 64.1 mol% for strain PB108. DNA-DNA hybridization value of type strain PB105^T with H. algoricola VUG-A23a^T was 32.3% (reciprocal 39.2). Based on the combined genotypic and phenotypic data, we propose that strains PB105^T and PB108 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter daejeonensis sp. nov. is proposed. The type strain is PB105^T (= KCTC 52579^T = JCM 31885^T).

Hymenobacter segetis sp. nov., isolated from soil

A polyphasic taxonomic study was performed on a novel strain designated as S7-3-11^T, which was isolated from soil of the Gyeongsangnam-do province in Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain S7-3-11^T belongs to the genus Hymenobacter and is most closely related to Hymenobacter ruber PB156^T (97.9%), Hymenobacter daeguensis 16F3Y-2^T (97.8%), Hymenobacter glaciei VUG-A130^T (97.7%), Hymenobacter soli PB17^T (97.5%), Hymenobacter terrae DG7A^T (97.5%), and Hymenobacter antarcticus VUG-A42aa^T (97.3%). However, DNA-DNA hybridization results showed less than 50% relatedness with respect to the type strains of the six most closely related species. The DNA G + C content of strain S7-3-11^T was 60.2 mol%. MK-7 was identified as the predominant respiratory quinone, and summed feature 3 (C_16:1 ω7c/C_16:1 ω6c; 21.5%), C_15:0 iso (16.8%), C_15:0 anteiso (16.2%), and C_15:1 iso G (10.8%) were the major fatty acids. Phosphatidylethanolamine, an unidentified aminolipid, and an unidentified aminophospholipid were detected as major polar lipids. On the basis of the polyphasic evidence presented, strain S7-3-11^T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter segetis sp. nov. is proposed. The type strain is S7-3-11^T (= KCTC 52732^T = JCM 32197^T).

Hymenobacter agri sp. nov., a novel bacterium isolated from soil

A bacterial isolate was recovered from a soil sample collected in Jeollabuk-do Province, South Korea, and subjected to polyphasic taxonomic assessment. Cells of the isolate, designated strain S1-2-1-2-1^T, were observed to be rod-shaped, pink in color, and Gram-stain negative. The strain was able to grow at temperature range from 10 to 30 °C, with an optimum of 25 °C, and growth occurred at pH 6-8. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-1-2-1^T belongs to the genus Hymenobacter, with closely related type strains being Hymenobacter daeguensis 16F3Y-2^T (95.8% similarity), Hymenobacter rubidus DG7B^T (95.8%), Hymenobacter soli PB^T (95.7%), Hymenobacter terrenus MIMtkLc17^T (95.6%), Hymenobacter terrae DG7A^T (95.3%), and Hymenobacter saemangeumensis GSR0100^T (95.2%). The genomic DNA G+C content of strain S1-2-1-2-1^T was 63.0 mol%. The main polar lipid of this strain was phosphatidylethanolamine, the predominant respiratory quinone was menaquinone-7, and the major fatty acids were C_15:0 iso (27.3%), summed feature 3 (C_16:1 ω7c/C_16:1 ω6c) (16.5%), C_15:0 anteiso (15.3%), and C_16:0 (14.7%), supporting the affiliation of this strain with the genus Hymenobacter. The results of this polyphasic analysis allowed for the genotypic and phenotypic differentiation of strain S1-2-1-2-1^T from recognized Hymenobacter species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S1-2-1-2-1^T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter agri sp. nov. is proposed. The type strain is S1-2-1-2-1^T (=KCTC 52739^T = JCM 32194^T).

Hymenobacter daeguensis sp. nov. isolated from river water

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterial strain, designated 16F3Y-2^T, was isolated from the Han River, South Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 16F3Y-2^T belonged to the family Cytophagaceae in the phylum Bacteroidetes and was most closely related to 'Hymenobacter terrae' DG7A (98.01%), H. soli PB17^T (97.26%), H. glaciei VUG-A130^T (96.78%), H. antarcticus VUG-A42aa^T (96.72%), H. ruber PB156^T (96.61%), and H. saemangeumensis GSR0100^T (95.77%). The G+C content of the genomic DNA of strain 16F3Y-2^T was 62.9 mol%. The isolate contained MK-7 as the predominant respiratory quinone, and summed feature 3 (C_16:1 ω7c/C_16:1 ω6c; 35.5%), C_15:0 iso (16.9%), C_16:1 ω5c (10.9%), and C_15:0 anteiso (9.9%) as major fatty acids. The major polar lipid was phosphatidylethanolamine. Phenotypic and chemotaxonomic data supported the affiliation of strain 16F3Y-2^T with the genus Hymenobacter. However, strain 16F3Y-2^T exhibited relatively low levels of DNA-DNA relatedness with 'H. terrae' KCTC 32554 (44.1%) and H. soli KCTC 12607^T (24.3%), clearly indicating that the isolate constitutes a new genospecies. Strain 16F3Y-2^T could be differentiated from its phylogenetic neighbors on the basis of several phenotypic, genotypic, and chemotaxonomic features. Therefore, strain 16F3Y-2^T represents a novel species in the genus Hymenobacter, for which the name Hymenobacter daeguensis sp. nov. is proposed. The type strain is 16F3Y-2^T (=KCTC 52537^T =JCM 31654^T).

Hymenobacter terrenus sp. nov., isolated from biological soil crusts

A Gram-stain-negative, non-spore-forming, short rod-shaped, non-motile, light-pink bacterial strain, MIMtkLc17T, was isolated from biological soil crusts collected in Liangcheng, Inner Mongolia. Growth of strain MIMtkLc17T was observed at 2–35 °C and in the presence of 1% (w/v) NaCl. Phylogenetic analysis of 16S rRNA gene sequences showed that sequence similarities between strain MIMtkLc17T and the type strains of species of the genus Hymenobacter ranged from 89.93% to 96.49%. Strain MIMtkLc17T can secrete mass polysaccharide. The major fatty acids of strain MIMtkLc17T were iso-C15 : 0, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C16 : 1ω5c and summed feature 4 (iso-C17 : 1 I/anteiso-C17 : 1 B). The sole respiratory quinone was menaquinone MK-7. The G+C content of the chromosomal DNA was 57.8 mol%. The results of phylogenetic, chemotaxonomic and phenotypic characterization indicated that strain MIMtkLc17T can be distinguished from all known species of the genus Hymenobacter and represents a novel species of this genus, for which the name Hymenobacter terrenus sp. nov. is proposed. The type strain is MIMtkLc17T ( = MCCC 1K00507T = KCTC 42636T).