Hymenobacter radiodurans sp. nov., isolated from soil in the Republic of Korea.

A bacterial strain, designated 17J36-26T, was isolated from the UV-irradiated soil from Jeju Island, South Korea. Cells are Gram negative, strictly aerobic, non-motile, non-spore forming, rod shaped, and catalase and oxidase positive. The major fatty acids of strain 17J36-26T were summed feature 4 (17:1 iso I/17:1 anteiso B), summed feature 3 (16:1 ω6c/16:1 ω7c), C16:1 ω5c and iso-C15:0. The polar lipid profile contained phosphatidylethanolamine, unidentified aminophospholipid, phospholipids and four unidentified lipids. The G+C content of the strain 17J36-26T was 62.6 mol%. The 16S rRNA gene sequence analysis showed that strain 17J36-26T was phylogenetically related to Hymenobacter qilianensis DK6-37T and Hymenobacter roseosalivarius AA718T (97.5% and 96.8% sequence similarity, respectively). Strain 17J36-26T showed resistance to UV radiation. Both average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strains 17J36-26T and type strains of Hymenobacter species were lower than the cut-off (≥ 95-96% for ANI and ≥ 70% for isDDH) to define a bacterial new species. The polyphasic approach using genotypic, phenotypic and chemotaxonomic data showed that strain 17J36-26T could be distinguished from its phylogenetically related species, and thus, the strain representative of a novel species within the genus Hymenobacter, for which the name Hymenobacter radiodurans sp. nov. (type strain 17J36-26T = KCTC 62269T = JCM 33185T) is proposed.

Hymenobacter busanensis sp. nov., radiation-resistant species isolated from soil in South Korea.

Two bacterial strains designated as MA3T and BT182 were isolated from a soil sample in South Korea. Cells of the two strains were Gram-stain-negative, non-motile, rod-shaped and formed red colonies on R2A agar at 25 °C. The 16S rRNA genes of the two strains shared a sequence similarity of 99.8%. Both strains shared the highest 16S rRNA gene similarity of 96.8% with Hymenobacter edaphi NLT, followed by Hymenobacter paludis KBP-30T (96.3%), Hymenobacter coalescens WW84T (96.3%) and Hymenobacter gummosus ANT-18T (96.3%). Growth was observed at 15-37 °C (optimum 30 °C), pH 6-8 (optimum pH 7) and in the presence up to 1% NaCl. The genome size of strains MA3T and BT182 is 4.9 Mb and 4.8 Mb, respectively. The genomic G + C content of both strains is 62.0 mol%. The main polar lipid of the strains was phosphatidylethanolamine, the only respiratory quinone detected was menaquinone-7 and the major fatty acids were anteiso-C15:0, iso-C15:0, summed feature 4 (iso-C17:1 I/anteiso-C17:1 B) and summed feature 3 (C16:1 ω6c/C16:1 ω7c), supporting the affiliation of these strains with the genus Hymenobacter. Based on the phylogenetic, genotypic, phenotypic and chemotaxonomic data, strains MA3T and BT182 represent a novel species of the genus Hymenobacter, for which the name Hymenobacter busanensis is proposed. The type strain is MA3T (= KCTC 72631T = NBRC 114193T).

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

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

Spirosoma knui sp. nov., a radiation-resistant bacterium isolated from the Han River.

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterium, designated 15J8-12T, was isolated from a water sample after exposure to 3 kGy of gamma radiation. The strain showed resistance to gamma radiation with a dose required to reduce the bacterial population 10 fold (D10) value of 4.7 kGy. The results of comparative 16S rRNA gene sequence analysis indicated that strain 15J8-12T represented a member of the family Cytophagaceae, phylum Bacteroidetes, and was most closely related to 'Spirosomafluminis' 15J17 (97.92 %) and Spirosoma arcticum R2-35T (92.22 %). The G+C content of the genomic DNA of 15J8-12T was 51.3 mol%. The detection of menaquinone MK-7 as the predominant respiratory quinone, a fatty acid profile with summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 40.5 %), C16 : 1ω5c (35.3 %), C15 : 0 iso (6.9 %) and C16 : 0 (6.8 %) as the major components and phosphatidylethanolamine as the major polar lipid also supported the affiliation of 15J8-12T with the genus Spirosoma. The DNA-DNA relatedness between 15J8-12T and 'Spirosoma fluminis' 15J17 was 27.8 %. On the basis of its phenotypic and genotypic properties, together with its phylogenetic distinctiveness, 15J8-12T should be considered to be a representative of a novel species of the genus Spirosoma, for which the name Spirosoma knui sp. nov. is proposed. The type strain is 15J8-12T (=KCTC 52510T=JCM 31407T).

Spirosoma fluminis sp. nov., a Gamma-Radiation Resistant Bacterium Isolated from Sediment of the Han River in South Korea.

A Gram-negative, long rod-shaped, and yellowish bacterium, designated as strain 15J17T(T), was isolated from sediment of the Han River in South Korea after exposure to 3 kGy of gamma radiation. The strain was catalase- and oxidase-positive and showed resistance to gamma radiation-D10 value (i.e., the dose required to reduce the bacterial population by 10-fold) of >4 kGy. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain belonged to the genus Spirosoma and showed moderate degrees of sequence similarity with related species (90.6-93.5 %). Chemotaxonomic data revealed that the strain contained summed feature 3 (C16:1 ω7c/C16:1 ω6c), C16:1 ω5c, C16:0, C18:0, and C15:0 iso as the major fatty acids; phosphatidylethanolamine, an unidentified aminophospholipid, and an unidentified polar lipid as the major polar lipids; and menaquinone-7 (MK-7) as the major quinone. The genomic DNA G+C content of the new strain was 48.3 mol%. Based on these data, type strain 15J17T(T) (=KCTC 52198(T) = JCM 31409(T)) should be classified as representing a new species, for which we propose the name Spirosoma fluminis sp. nov.

Complete genome sequence of ionizing radiation-resistant Hymenobacter sp. strain PAMC26628 isolated from an Arctic lichen.

Ionizing radiation-resistant Hymenobacter sp. strain PAMC26628 was isolated from Stereocaulon sp., an Arctic lichen. Complete genome sequencing of Hymenobacter sp. PAMC26628 revealed one chromosome (5,277,381 bp), one plasmid (89,596 bp), and several genes involved in nucleotide excision repair, a DNA damage removal pathway. An analysis of the Hymenobacter sp. PAMC26628 genome will help us understand its evolution and provide novel insight into the adaptations that allow this organism to survive in the extreme cold of the Arctic.

Complete genome sequence of Hymenobacter sp. DG25B, a novel bacterium with gamma-radiation resistance isolated from soil in South Korea.

A Gram-negative, rod-shaped, non-motile, gamma and UV radiation resistant bacterium Hymenobacter radioresistens DG25B was isolated from a soil sample collected in South Korea. The complete genome sequence of H. radioresistens DG25B consists of one circular chromosome (3,874,646 bp). The bacterium was isolated from gamma ray irradiated soil and contains the genomic features of enzymes involved in the nucleotide excision repair (NER) pathway that protect the damaged DNA. The genome also contains other genes involved in the efficient removal of double-strand breaks (DSB) caused by the ionizing radiations.

Spirosoma montaniterrae sp. nov., an ultraviolet and gamma radiation-resistant bacterium isolated from mountain soil.

A Gram-negative, yellow-pigmented, long-rod shaped bacterial strain designated DY10(T) was isolated from a soil sample collected at Mt. Deogyusan, Jeonbuk province, South Korea. Optimum growth observed at 30°C and pH 7. No growth was observed above 1% (w/v) NaCl. Comparative 16S rRNA gene sequence analysis showed that strain DY10(T) belonged to the genus Spirosoma and was distantly related to Spirosoma arcticum R2-35(T) (91.0%), Spirosoma lingual DSM 74(T) (90.8%), Spirosoma endophyticum EX36(T) (90.7%), Spirosoma panaciterrae DSM 21099(T) (90.5%), Spirosoma rigui WPCB118(T) (90.2%), Spirosoma spitsbergense DSM 19989(T) (89.8%), Spirosoma luteum DSM 19990(T) (89.6%), Spirosoma oryzae RHs22(T) (89.6%), and Spirosoma radiotolerans DG5A(T) (89.1%). Strain DY10(T) showed resistance to gamma and ultraviolet radiation. The chemotaxonomic characteristics of strain DY10(T) were consistent with those of the genus Spirosoma, with the quinone system with MK-7 as the predominant menaquinone, iso-C15:0, C16:1 ω5c, and summed feature3 (C16:1 ω7c/C16:1 ω6c), and phosphatidylethanolamine as the major polar lipid. The G+C content of the genomic DNA was 53.0 mol%. Differential phenotypic properties with the closely related type strains clearly distinguished strain DY10(T) from previously described members of the genus Spirosoma and represents a novel species in this genus, for which the name Spirosoma montaniterrae sp. nov. is proposed. The type strain is DY10(T) (=KCTC 23999(T) =KEMB 9004-162(T) =JCM 18492(T)).

Spirosoma radiotolerans sp. nov., a gamma-radiation-resistant bacterium isolated from gamma ray-irradiated soil.

A Gram-negative, short-rod-shaped bacterial strain with gliding motility, designated as DG5A(T), was isolated from a rice field soil in South Korea. Phylogenic analysis using 16S rRNA gene sequence of the new isolate showed that strain DG5A(T) belong to the genus Spirosoma in the family Spirosomaceae, and the highest sequence similarities were 95.5 % with Spirosoma linguale DSM 74(T), 93.4 % with Spirosoma rigui WPCB118(T), 92.8 % with Spirosoma luteum SPM-10(T), 92.7 % with Spirosoma spitsbergense SPM-9(T), and 91.9 % with Spirosoma panaciterrae Gsoil 1519(T). Strain DG5A(T) revealed resistance to gamma and UV radiation. Chemotaxonomic data showed that the most abundant fatty acids were summed feature C(16:1) ω7c/C(16:1) ω6c (36.90 %), C(16:1) ω5c (29.55 %), and iso-C(15:0) (14.78 %), and the major polar lipid was phosphatidylethanolamine (PE). The DNA G+C content of strain DG5A(T) was 49.1 mol%. Together, the phenotypic, phylogenetic, and chemotaxonomic data supported that strain DG5A(T) presents a novel species of the genus Spirosoma, for which the name Spirosoma radiotolerans sp. nov., is proposed. The type strain is DG5A(T) (=KCTC 32455(T) = JCM19447(T)).

Hymenobacter kanuolensis sp. nov., a novel radiation-resistant bacterium.

A Gram-reaction-negative, rod-shaped, non-motile, red-pigmented, radiation-resistant, aerobic bacterium designated T-3(T) was isolated from a soil sample from the Qinghai-Tibet Plateau in Tibet, China, after exposure to 10 kGy gamma radiation. Phylogenetic analysis based on 16S rRNA sequences indicated that this isolate represented a novel member of the genus Hymenobacter. Sequence identities of the 16S rRNA gene of strain T-3(T) with the type strains of species of the genus Hymenobacter with validly published names range from 89% to 97%, and the most closely related species is Hymenobacter psychrotolerans Tibet-IIU11(T) (97%). The DNA-DNA relatedness between strain T-3(T) and H. psychrotolerans is 59.10%. The major fatty acids of strain T-3(T) were iso-C(15 : 0) (27.66%), summed feature 4 (iso-C(17 : 1)I and/or anteiso-C(17 : 1)B, 15.84%), anteiso-C(15 : 0) (14.08%) and summed feature 3 (C(16 : 1)ω7c and/or C(16 : 1)ω6c, 12.38%). The major menaquinone of strain T-3(T) was MK-7. Phosphatidylethanolamine (PE) was predominant in the polar lipid profile. The G+C content of the DNA of strain T-3(T) was 69.17 mol%. On the basis of the results of the polyphasic characterization presented in this study, it is concluded that strain T-3(T) represents a novel species of the genus Hymenobacter, for which the name Hymenobacter kanuolensis is proposed. The type strain is T-3(T) ( = ACCC 05760(T) = KCTC 32407(T)).

Hymenobacter swuensis sp. nov., a gamma-radiation-resistant bacteria isolated from mountain soil.

Gram stain-negative and non-motile bacteria, designated as DY53(T) and DY43, were isolated from mountain soil in South Korea prior exposure with 5 kGy gamma radiation. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strains belonged to the family Cytophagaceae in the class Cytophagia. 16S rRNA gene sequence similarity of strains DY53(T) and DY43 was 100 %. The highest degrees of sequence similarities of strains DY53(T) and DY43 were found with Hymenobacter perfusus A1-12(T) (98.8 %), Hymenobacter rigui WPCB131(T) (98.5 %), H. yonginensis HMD1010(T) (97.9 %), H. xinjiangensis X2-1g(T) (96.6 %), and H. gelipurpurascens Txg1(T) (96.5 %). The DNA G+C content of the novel strains DY53(T) and DY43 were 59.5 mol%. Chemotaxonomic data revealed that strains possessed major fatty acids such as C15:0 iso, C15:0 anteiso, C16:1 ω5c, summed feature 3 (16:1 ω7c/ω6c), summed feature 4 (17:1 anteiso B/iso I) and C17:0 iso, and major polar lipid was phosphatidylethanolamine. The novel strains showed resistance to gamma radiation, with a D10 value (i.e., the dose required to reduce the bacterial population by tenfold) in excess of 5 kGy. Based on these data, strains DY53(T) and DY43 should be classified as representing a novel species, for which the name Hymenobacter swuensis sp. nov. is proposed, with the type strain DY53(T) (=KCTC 32018(T) = JCM 18582(T)) and DY43 (=KCTC 32010).

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

A Gram-negative, non-motile, rod-shaped and pink-pigmented bacterium, designated strain X2-1g(T), was isolated from a mixture of sand samples collected from the desert of Xinjiang, China, after exposure of the sand to 8 kGy gamma radiation. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that this isolate represents a novel member of the genus Hymenobacter, with low sequence similarities (<97 %) to recognized Hymenobacter species. Biolog GN2 assays supported this conclusion. Optimum growth was observed at pH 7 and 28 degrees C. The strain contained MK-7 as the predominant menaquinone and the major fatty acids were iso-C(15 : 0) (19.5 %), C(16 : 1) omega 7c/iso-C(15 : 0) 2-OH (20.2 %), C(16 : 1) omega 5c (10.6 %), C(16 : 0) (6.2 %), anteiso-C(17 : 1) B/iso-C(17 : 1) I (8.5 %) and C(18 : 0) (6.5 %). The DNA G+C content was 54 mol% (T(m)). On the basis of the polyphasic evidence presented, it is proposed that strain X2-1g(T) represents a novel species of the genus Hymenobacter, for which the name Hymenobacter xinjiangensis sp. nov. is proposed. The type strain is X2-1g(T) (=CCTCC AB 206080(T) =IAM 15452(T)).