Characterization of radiation-resistance mechanism in Spirosoma montaniterrae DY10T in terms of transcriptional regulatory system.

To respond to the external environmental changes for survival, bacteria regulates expression of a number of genes including transcription factors (TFs). To characterize complex biological phenomena, a biological system-level approach is necessary. Here we utilized six computational biology methods to infer regulatory network and to characterize underlying biologically mechanisms relevant to radiation-resistance. In particular, we inferred gene regulatory network (GRN) and operons of radiation-resistance bacterium Spirosoma montaniterrae DY10[Formula: see text] and identified the major regulators for radiation-resistance. Our results showed that DNA repair and reactive oxygen species (ROS) scavenging mechanisms are key processes and Crp/Fnr family transcriptional regulator works as a master regulatory TF in early response to radiation.

Hymenobacter lucidus sp. nov., and Hymenobacter nitidus sp. nov., isolated from soil.

Two novel bacterial strains BT178T and BT635T were isolated from soil collected in Gyeonggi province, Republic of Korea. Both strains were Gram-negative, rod-shaped circular, and had convex, glistening, pink-colored colonies. Phylogenetic analysis based on 16S rRNA gene sequences showed that each of the strains BT178T and BT635T formed an individual lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia, phylum Bacteroidetes). The 16S rRNA gene sequence similarity between the two strains BT178T and BT635T were 97.7%. Both strains had Q-7 as the major respiratory quinone and phosphatidylethanolamine (PE) as the major polar lipids. The main cellular fatty acids of strain BT178T were iso-C15:0, anteiso-C15:0, and those of strain BT635T were iso-C15:0 and Summed Feature 4 (iso-C17:1 I / anteiso-C17:1 B). Based on the result of polyphasic taxonomic analysis, two novel species, Hymenobacter lucidus BT178T (= KCTC 72333T = NBRC 115442T) and Hymenobacter nitidus BT635T (= KACC 21904T = NBRC 115443T) were proposed.

Microvirga terrestris sp. nov., and Microvirga arvi sp. nov., isolated from soil in South Korea.

Two novel Gram-stain-negative, aerobic, rod shaped bacterial strains BT290T and BT689T were isolated from soil collected in South Korea. Colony morphologies of both strains were circular and convex while the colors of BT290T and BT689T were light-pink and white, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that BT290T and BT689T belong to a distinct lineage within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alphaproteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rR NA gene sequence similarity between two strains was 97.9%. Both strains had the similar quinone system, with ubiquinone 10 (Q-10) as the major respiratory quinone. The major polar lipids of strains BT290T and BT689T were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylcholine (PC), and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT290T were C18:1 ω7c (58.2%) and C16:0 (17.7%), while those of strain BT689T were C18:1 ω7c (61.8%) and C16:0 (10.8%). On the bases of polyphasic analysis (phylogenetic, chemotaxonomic, and biochemical), strains BT290T and BT689T can be suggested as novel bacterial species within the genus Microvirga and the proposed names are Microvirga terrestris and Microvirga arvi, respectively. The type strain of Microvirga terrestris is BT290T (= KCTC 72367T = NBRC 114844T) and the type strain of Microvirga arvi is BT689T (= KACC 22016T = NBRC 114858T), respectively.

Hymenobacter translucens sp. nov. and Hymenobacter pini sp. nov. isolated from soil.

Two novel bacterial strains BT175T and BT728T were isolated from soil collected in the Republic of Korea. Both strains were Gram stain negative, rod shaped, and had circular, convex, and pink-colored colonies. The 16S rRNA gene sequence similarity between the strains BT175T and BT728T was 93.6%, indicating that they represent a distinct species. 16S rRNA sequence analysis indicated that strains BT175T and BT728T belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia, phylum Bacteroidetes). Strain BT175T was closely related to Hymenobacter persicinus 1-3-3-3T (97.2%, 16S rRNA gene similarity), Hymenobacter knuensis 16F7C-2T (96.6%), and Hymenobacter daejeonensis PB105T (96.1%). Strain BT728T was closely related to Hymenobacter rigui KCTC 12533T (98.4%), Hymenobacter metallilatus 9PBR-2T (97.6%), and Hymenobacter perfusus LMG26000T (97.4%). Strain BT175T and BT728T were found to have the MK-7 as the major respiratory quinone. The DNA G + C content of strain BT175T was 61.6 mol% and BT728T was 59.6 mol%, respectively. Characterization based on polyphasic analysis indicated that strains BT175T and BT728T represent novel species of the genus Hymenobacter and the names Hymenobacter translucens sp. nov. and Hymenobacter pini sp. nov. are proposed. The type strain of Hymenobacter translucens is BT175T (= KCTC 72330T = NBRC 115441T) and Hymenobacter pini is BT728T (= KACC 22629T = NBRC 115444T).

Microvirga splendida sp. nov., bacteria isolated from soil.

Two bacterial strains, BT325T and BT690, were isolated from soil samples collected in Korea. Both strains were Gram stain-negative, short rod-shaped, and formed light-pink colored colonies. The 16S rRNA sequence similarity of strains BT325T and BT690 shared a sequence similarity of 99.7%. Both strains shared the highest 16S rRNA gene similarity of 98.6% with Microvirga arabica SV2184PT, followed by Microvirga ossetica V5/3 M T (98.5% and 98.2%, respectively), Microvirga soli R491T (98.3% and 98.2%, respectively), Microvirga aerilata (98.2% and 98.08%, respectively), Microvirga makkahensis (98.08% and 97.8%, respectively). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain BT325T and BT690 were positioned in a distinct lineage within the family Methylobacteriaceae (order Rhizobiales, class Alphaproteobacteria). The genome size of strain BT325T was 5,200,315 bp and the genomic DNA G + C content was 64.3 mol%. The sole respiratory quinone of strain BT325T was Q-10 and the predominant cellular fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c) and summed feature 8 (C18:1 ω7c/C18:1 ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. Polyphasic taxonomic analysis of biochemical, chemotaxonomic, and phylogenetic analyses suggested that strains BT325T represents a novel bacterial species within the genus Microvirga, for which the name Microvirga splendida is proposed. The type strain of Microvirga splendida is BT325T (= KCTC 72406 T = NBRC 114847 T).

Microvirga jeongseonensis sp. nov., isolated from soil in South Korea.

A novel Gram-stain-negative, aerobic, rod-shaped, convex, and light pink-colored strain BT688T was isolated from a soil sample collected in Jeongseon City, South Korea. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain BT688T belongs to a distinct lineage within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alphaproteobacteria, phylum Proteobacteria). The 16S rRNA gene sequence similarity between strain BT688T and Microvirga aerilata 5420S-16T was 98.5%. Strain BT688T had Q-10 as a major respiratory quinone and the major polar lipids were diphosphatidilglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). The major cellular fatty acids of strain BT688T were C18:1 ω7c (76.0%) and summed feature 3 (9.6%). Based on the polyphasic characteristics, strain BT688T represents a novel bacterial species within the genus Microvirga and the proposed name is Microvirga jeongseonensis. The type strain of Microvirga jeongseonensis is BT688T (= KCTC 82701T = NBRC 114857T).

Hymenobacter armeniacus sp. nov. and Hymenobacter montanus sp. nov., two radiation-resistant bacteria from soil.

Two bacterial strains, designated BT189T and BT664T, were isolated from soil sampled in the Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strains BT189T and BT664T belonged to the genus Hymenobacter, family Hymenobacteraceae (order Cytophagales). The 16S rRNA genes of the two strains shared a sequence similarity of 93.7 %. The closely related species of strain BT189T were Hymenobacter rubidus DG7BT (97.1 % 16S rRNA similarity) and Hymenobacter terrae DG7AT (96.7 %). The closest related species to strain BT664T were Hymenobacter sedentarius DG5BT (95.3 %) and Hymenobacter terrenus MIMtkLc17T (95.2 %). The genome sizes of strains BT189T and BT664T were 5 285 287 and 5 475 357 bp, respectively. The genomic DNA G+C contents of strains BT189T and BT664T were 63.2 and 59.3 mol%, respectively. The main fatty acids of strain BT189T were iso-C15 : 0, anteiso-C15 : 0 and summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c), and those of strain BT664T were iso-C15 : 0, C16 : 1 ω5c and summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c). The main polar lipid in both strains was phosphatidylethanolamine and the predominant respiratory quinone was MK-7, supporting the affiliation of these strains with the genus Hymenobacter. Based on the results of biochemical, chemotaxonomic and phylogenetic analyses, two novel species, Hymenobacter armeniacus BT189T (=KCTC 72341T=NBRC 114843T) and Hymenobacter montanus BT664T (KACC 21967T=NBRC 114856T), are proposed.

Larkinella humicola sp. nov., a gamma radiation-resistant bacterium isolated from soil.

A Gram-negative, short rod-shaped, and pink-pigmented bacterial strain, designated MA1T, was isolated from a soil sample from Gijang-gun, Busan in Republic of Korea. The 16S rRNA gene sequence analysis showed that strain MA1T belonged to the genus Larkinella and was closely related to "Larkinella punicea" (97.5% similarity), Larkinella rosea 15J16-1T3AT (96.5%), and Larkinella knui 15J6-3T6T (96.2%). Polar lipid profile of strain MA1T contained phosphatidylethanolamine, two unidentified aminolipids, and three unidentified lipids. Menaquinone-7 was the only quinone and the main fatty acids were C16:1 ω5c (36.7%), iso-C15:0 (30.0%), iso-C17:0 3-OH (7.7%), and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c and/or iso-C15:0 2-OH) (7.3%). The genomic DNA G + C content was 52.3 mol% based on the whole-genome analysis. Strain MA1T exhibited a relatively low level of ANI and in silico DDH values with "Larkinella punicea" (91.9 and 47.1%, respectively), Larkinella rosea (79.7 and 23.3%), and Larkinella knui (81.9 and 25.7%). Based on its phenotypic properties and phylogenetic distinctiveness, strain MA1T should be classified in the genus Larkinella as a representative of a novel species, for which the name Larkinella humicola sp. nov. is proposed. The type strain is MA1T (= KCTC 72629T = NBRC 114191T).

Pedobacter segetis sp. nov., a Novel Bacterium Isolated from Soil.

A Gram-negative, motile by gliding, rod-shaped, aerobic bacterium, designated SD-bT, was isolated from a soil sample collected on Dokdo Island, South Korea. A polyphasic approach based on phenotypic, phylogenetic, and genomic analyses was used to characterize the new isolate. Phylogenetic analysis of 16S rRNA gene sequence showed that strain SD-bT belonged to the family Sphingobacteriaceae and most closely related to Pedobacter psychrophilus P4487AT (95.9% similarity). The isolate contained MK-7 as the predominant respiratory quinone; its main polar lipid was phosphatidylethanolamine; and the major fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c; 32.0%), C15:0 iso (19.1%), C17:0 iso 3-OH (8.3%), and C16:0 (8.2%). The draft genome had a length of 3,842,102 bp with a G+C content of 36.0 mol%, predicting 3282 coding sequences, 3 rRNA genes, 3 ncRNAs, and 36 tRNAs genes. The digital DNA-DNA hybridization and average nucleotide identity values between strain SD-bT and P. psychrophilus LMG 29436T were 22.0% and 78.9%, respectively. The results of phenotypic properties, genotypic distinctiveness, and chemotaxonomic features support the discrimination of SD-bT from its phylogenetic relatives. Pedobacter segetis sp. nov. is therefore proposed with SD-bT (= KCTC 82351T = JCM 34283T) as the type strain.

Hymenobacter telluris sp. nov., isolated from soil in South Korea.

Two novel bacterial strains, designated as BT186T and BT505, were isolated from a soil sample collected in South Korea and characterized. Both strains were Gram-stain-negative, rod-shaped, aerobic, circular, convex, and had red-colored colonies. The level of 16S rRNA gene sequence similarity between the strains BT186T and BT505 was 100%, indicating that they represent an identical species. 16S rRNA sequence analysis indicated that strains BT186T and BT505 belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia, phylum Bacteroidetes, Kingdom Bacteria). Both strains were closely related to Hymenobacter norwichensis DSM 15439T (98.3% 16S rRNA gene similarity), Hymenobacter aquaticus JCM 31653T (96.8%), and Hymenobacter perfusus LMG26000T (96.5%). Strain BT186T was found to have the MK-7 as the major respiratory quinone. The major polar lipid of strain BT186T was identified to be phosphatidylethanolamine (PE). The major cellular fatty acid profiles of strain BT186T were C16:1 ω5c (24.3%), iso-C15:0 (20.3%) and summed feature 3 (C16:1 ω6c/C16:1 ω7c) (19.9%). Characterization based on polyphasic analysis indicated that strains BT186T and BT505 represent novel species of the genus Hymenobacter and the name Hymenobacter telluris sp. nov. is proposed. The type strain of Hymenobacter telluris is BT186T (= KCTC 72338T = NBRC 114968T).

Description of Vishniacozyma terrae sp. nov. and Dioszegia terrae sp. nov., Two Novel Basidiomycetous Yeast Species Isolated from Soil in Korea.

Two strains, YP344 and YP579 were isolated from soil samples in Pocheon City, Gyeonggi Province, South Korea. The strains YP344 and YP579 belong to the genus Vishniacozyma and Dioszegia, respectively. The molecular phylogenetic analysis showed that the strain YP344 was closely related to Vishniacozyma peneaus. Strain YP344T differed by four nucleotide substitutions with no gap (0.70%) in the D1/D2 domain of the LSU rRNA gene and 16 nucleotide substitutions with 8 gaps (5.76%) in the ITS region. On the other hand, the strain YP579T varied from the type strain of the most closely related species, Dioszegia zsoltii var. zsoltii, by 6 nucleotide substitutions with four gaps (1.64%) in the D1/D2 domain of LSU rRNA gene and 26 nucleotide substitutions with 14 gaps (8.16%) in the ITS region. Therefore, the name Vishniacozyma terrae sp. nov. and Dioszegia terrae sp. nov. are proposed, with type strains YP344T (KCTC27988T) and YP579T (KCTC 27998T), respectively.

Microvirga pudoricolor sp. nov., and Microvirga alba sp. nov., isolated from soil in South Korea.

Two novel Gram-stain-negative, aerobic, rod-shaped, circular, convex, light-pink and white-colored bacterial strains BT291T and BT350T were isolated from soil collected in Uijeongbu city (37° 44' 55″ N, 127° 2' 20″ E) and Jeju island (33° 22' 48″ N, 126° 31' 48″ E), respectively, South Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that each of the strains BT291T and BT350T belong to a distinct lineages within the genus Microvirga (family Methylobacteriaceae, order Rhizobiales, class Alpha Proteobacteria, phylum Proteobacteria, kingdom Bacteria). The 16S rRNA gene sequence similarity between the two strains BT291T and BT350T was 97.4%. The two strains were found to have the same quinone system, with Q-10 as the major respiratory quinone. The major polar lipids of strains BT291T and BT350T were phosphatidylethanolamine (PE), diphosphatydilglycerol (DPG), phosphatidylcholine (PC) and phosphatidylglycerol (PG). The major cellular fatty acids of strain BT291T were C18:1 ω7c (58.2%) and cyclo-C19:0 ω8c (25.7%). The major cellular fatty acids of strain BT350T were C18:1 ω7c (38.5%) and cyclo-C19:0 ω8c (27.7%). Based on the polyphasic analysis (phylogenetic, chemotaxonomic and biochemical), strains BT291T and BT350T can be suggested as two novel bacterial species within the genus Microvirga and the proposed names are Microvirga pudoricolor and Microvirga alba, respectively. The type strain of Microvirga pudoricolor is BT291T (= KCTC 72368T = NBRC 114845T) and the type strain of Microvirga alba is BT350T (= KCTC 72385T = NBRC 114848T).

Hymenobacter puniceus sp. nov., radiation resistant bacteria isolated from soil in South Korea.

Two novel Gram-negative bacterial strains BT190T and BT191 were isolated from soil collected in Uijeongbu city (37°44'55″N, 127°02'20″E), Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains BT190T and BT191 belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia). The level of 16S rRNA gene sequence similarity between the strains BT190T and BT190 was 99.5%. The strains BT190T and BT191 were closely related to Hymenobacter swuensis DY53T (97.0% 16S rRNA gene similarity), Hymenobacter metallilatus 9PBR-2 T (96.8%), Hymenobacter tibetensis XTM003T (96.8%) and Hymenobacter yonginensis HMD1010T (96.6%). The genome size of strain BT190T was 4,859,864 bp. The DNA G+C content of strain BT190T was 55.3 mol%. Bacterial growth was observed at 4-30 °C (optimum 25 °C) and pH 6.0-9.0 (optimum, pH 6.0-7.0) on R2A agar. Colonies of strains BT190T and BT191 were raised, smooth, circular and red-pink colored. The sole respiratory quinone of strain BT190T was MK-7 and the predominant cellular fatty acids were iso-C15:0, C16:1 ω5c, summed feature 3 (C16:1 ω6c / C16:1 ω7c) and summed feature 4 (iso-C17:1 I / anteiso-C17:1 B). The major polar lipids of strain BT190T were aminophospholipid (APL) and phosphatidylethanolamine (PE). Based on the chemotaxonomic, biochemical, and phylogenetic analysis, strains BT190T and BT191 can be suggested as a novel bacterial species within the genus Hymenobacter, for which the name Hymenobacter puniceus sp. nov is proposed. The type strain of Hymenobacter puniceus is BT190T (= KCTC 72342 T = NBRC 114860 T).

Hymenobacter guriensis sp. nov., and Hymenobacter duratus sp. nov., Radiation-Resistant Species Isolated from Soil in South Korea.

Two novel Gram-stain-negative, non-motile, aerobic, rod-shaped, circular, convex, red-colored and UV-tolerant strains BT594T and BT646T were isolated from soil collected in Guri city (37° 36' 0″ N, 127° 9' 0″ E) and Gwangju city (37° 22' 0″ N, 127° 17' 0″ E), respectively, South Korea. 16S rDNA sequence analysis indicated that strains BT594T and BT646T belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia, phylum Bacteroidetes, kingdom Bacteria). The 16S rDNA gene sequence similarity between the two strains BT594T and BT646T was 96.2%. The strain BT594T was closely related to Hymenobacter psychrotolerans Tibet-IIU11T (97.0% 16S rDNA gene similarity) and Hymenobacter tibetensis XTM003T (96.3%). The strain BT646T was closely related to Hymenobacter psychrotolerans Tibet-IIU11T (98.6%), Hymenobacter kanuolensis T-3 T (96.8%) and Hymenobacter perfusus LMG 26000 T (96.7%). The two strains were found to have the same quinone system, with MK-7 as the major respiratory quinone. The major polar lipids of strains BT594T and BT646T were phosphatidylethanolamine (PE) and aminophospholipids (APL). The major cellular fatty acids of strain BT594T were anteiso-C15:0 (17.9%), iso-C15:0 (16.1%) and summed feature 3 (C16:1 ω6c / C16:1 ω7c) (10.0%). The major cellular fatty acids of strain BT646T were summed feature 3 (C16:1 ω6c / C16:1 ω7c) (18.3%), C16:0 (17.2%) and summed feature 4 (iso-C17:1 I / anteiso-C17:1 B) (14.5%). Based on the polyphasic analysis, strains BT594T and BT646T can be suggested as two novel bacterial species within the genus Hymenobacter and the proposed names are Hymenobacter guriensis and Hymenobacter duratus, respectively. The type strain of Hymenobacter guriensis is BT594T (= KCTC 21863 T = NBRC 114853 T) and the type strain of Hymenobacter duratus is BT646T (= KCTC 21915 T = NBRC 114854 T).

Adhaeribacter terrigena sp. nov., Isolated from Korean Soil.

A bacterial strain, designated BT258T, was isolated from a soil sample collected from Uijeongbu-si, Gyeong-do Province, Republic of Korea. Cells were Gram stain negative, aerobic, rod shaped, motile by gliding, and formed light pink-pigmented colonies on agar plates. Growth of the isolate was observed at 10-37 °C and pH 6-7. A 16S rRNA gene sequence analysis revealed that strain BT258T is a member of the genus Adhaeribacter in the family Hymenobacteraceae and had the highest sequence similarity with 'Adhaeribacter soli' MA2T (97.1%), Adhaeribacter terreus DNG6T (96.6%), and Adhaeribacter terrae HY02T (96.5%). The predominant respiratory quinone of the isolate was MK-7, the main polar lipid was phosphatidylethanolamine, and the major fatty acids were C15:0 iso (37.7%), summed feature 4 (C17:1 anteiso B/iso-C17:1 I; 16.8%), and C16:0 (10.3%). The draft genome of strain BT258T had a whole length of 4,974,022 bp and DNA G + C content of 46.0 mol%. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the novel isolate and 'Adhaeribacter soli' and seven other Adhaeribacter species ranged from 17.9 to 22.7% and 69.7 to 77.9%, respectively. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain BT258T represents a novel species in the genus Adhaeribacter, for which the name Adhaeribacter terrigena sp. nov. is proposed. The type strain is BT258T (= KCTC 72409 T = JCM 34303 T).

Flavobacterium agrisoli sp. nov., a novel bacterium isolated from soil.

A Gram-stain negative, rod shaped, motile by gliding, yellow-pigmented, aerobic bacterium, designated SE-1-eT, was isolated from a soil sample collected on Dokdo Island, South Korea. The isolate was characterized taxonomically using a polyphasic approach based on the phenotypic and genomic analyses. The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain SE-1-eT belonged to the genus Flavobacterium in the family Flavobacteriaceae and had the highest sequence similarity with Flavobacterium cheongpyeongense IMCC34759T (97.5%), Flavobacterium arsenitoxidans S2-3HT (97.4%), Flavobacterium resistens BD-b365T (97.4%), and Flavobacterium chungangense CJ7T (97.4%). The predominant respiratory quinone of the isolate was found to be MK-6; the main polar lipid was phosphatidylethanolamine; and the major fatty acids were identified as summed feature 3 (C16:1 ω7c/C16:1 ω6c), C15:0 iso, and C16:0. The draft genome of strain SE-1-eT had a length of 3,715,609 bp and a DNA G + C content of 34.8 mol%. The nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the novel isolate and F. cheongpyeongense IMCC34759T, F. resistens BD-b365T, and Flavobacterium chungangense CJ7T ranged from 74.9 to 75.3% and from 20.2 to 20.9%, respectively. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain SE-1-eT represents a novel species in the genus Flavobacterium, for which the name Flavobacterium agrisoli sp. nov. is proposed. The type strain is SE-1-eT (= KCTC 82352 T = JCM 34302 T).

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

Two novel Gram-negative bacterial strains BT442T 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 BT442T and BT584 both belong to a distinct lineage within the genus Hymenobacter (family Hymenobacteraceae, order Cytophagales, class Cytophagia). Strain BT442T was closely related to Hymenobacter soli PB17T (98.0% 16S rRNA gene similarity) and Hymenobacter terrae POA9T (97.6%). No other recognized bacterial species showed more than 97% 16S rRNA gene sequence similarity to strains BT442T. The genome size of strain BT442T 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 BT442T and BT584 were iso-C15:0, anteiso-C15:0 and summed feature 3 (C16:1 ω6c / C16:1 ω7c). In addition, their predominant respiratory quinone was MK-7. The major polar lipids of strains BT442T and BT584 were identified to be phosphatidylethanolamine, aminophospholipid, and aminolipid. Based on the biochemical, chemotaxonomic, and phylogenetic analyses, strains BT442T and BT584 are novel bacterial species within the genus Hymenobacter, and the proposed name is Hymenobacter negativus. The strain type of Hymenobacter negativus is BT442T (= KCTC 72902T = NBRC XXXXT).

Spirosoma profusum sp. nov., and Spirosoma validum sp. nov., radiation-resistant bacteria isolated from soil in South Korea.

Two novel Gram-negative, rod-shaped bacterial strains BT702T and BT704T were isolated from soil collected in Jeongseon (37° 22' 45″ N, 128° 39' 53″ E), Gangwon province, South Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains BT702T and BT704T belong to distinct lineage within the genus Spirosoma (family Cytophagaceae, order Cytophagales, class Cytophagia and phylum Bacteroidetes). The strain BT702T was closely related to Spirosoma flavus 15J11-2T (96.7% 16S rRNA gene similarity) and Spirosoma metallilatum TX0405T (93.3%). The strain BT704T was closely related to Spirosoma koreense 15J8-5T (94.6%), Spirosoma endophyticum DSM 26130T (93.8%) and Spirosoma humi S7-4-1T (93.8%). The genome sizes of type strains BT702T and BT704T are 8,731,341 bp and 8,221,062 bp, respectively. The major cellular fatty acids of strains BT702T and BT704T were C16:1 ω5c and summed feature 3 (C16:1 ω6c/C16:1 ω7c). The strains were found to have the same quinone system, with MK-7 as the major respiratory quinone. The major polar lipids of strain BT702T was identified to be phosphatidylethanolamine (PE), aminophospholipid (APL) and aminolipid (AL), while that of strain BT704T consisted of phosphatidylethanolamine (PE) and aminophospholipid (APL). Based on the polyphasic analysis (phylogenetic, chemotaxonomic and biochemical), strains BT702T and BT704T can be suggested as two new bacterial species within the genus Spirosoma and the proposed names are Spirosoma profusum and Spirosoma validum, respectively. The type strain of Spirosoma profusum is BT702T (= KCTC 82115T = NBRC 114859T) and type strain of Spirosoma validum is BT704T (= KCTC 82114T = NBRC 114966T).

Mucilaginibacter segetis sp. nov., Isolated from Soil.

A bacterial strain, SD-gT, was isolated from a soil sample collected on Dokdo Island, South Korea. Cells were observed to be Gram stain negative and short rod shaped, and colonies to be pink in color. Growth of the isolate was observed at 4-30 °C, pH 6-8, and in the presence of 0-2.0% NaCl. Analysis of 16S rRNA gene sequences identified strain SD-gT as a member of the genus Mucilaginibacter in the family Sphingobacteriaceae, with high levels of sequence similarity with Mucilaginibacter terrenus ZH6T (96.9%), Mucilaginibacter lutimaris BR-3T (96.8%), Mucilaginibacter carri PR0008KT (96.8%), Mucilaginibacter gilvus F01003T (96.7%), Mucilaginibacter litoreus BR-18T (96.6%), and Mucilaginibacter terrigena 17JY9-4T (96.5%). The genomic DNA G+C content of strain SD-gT was calculated to be 40.6 mol%. The predominant respiratory quinone of the isolate was found to be MK-7; the main polar lipid was phosphatidylethanolamine; and the major fatty acids were identified as summed feature 3 (C16:1 ω7c/C16:1 ω6c; 29.0%), C15:0 iso (19.1%), C15:0 iso (28.1%), C16:0 (14.9%), and C17:0 iso 3-OH (7.4%). The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain SD-gT and M. terrenus ZH6T, M. gilvus F01003T, and M. terrigena ranged from 17.7 to 18.4% and 72.1 to 74.0%, respectively. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain SD-gT represents a novel species in the genus Mucilaginibacter, for which the name Mucilaginibacter segetis sp. nov. is proposed. The type strain is SD-gT (= KCTC 82353T = JCM 34284T).