Massilia litorea sp. nov., Marinobacter salinisoli sp. nov. and Rhodobacter xanthinilyticus sp. nov., isolated from coastal environments.

Three bacterial strains, namely LPB0304T, LPB0319T and LPB0142T, were isolated from coastal environments. The 16S rRNA gene sequences of the three isolates were found to show the highest sequence similarities to Massilia litorea (98.44 %), Marinobacter salinisoli (97.55 %) and Rhodobacter lacus (97.60 %), respectively. The low (<98.7 %) sequence similarities and tree topologies implied the novelty of the three isolates, representing novel genomic species of the genus Massilia, Marinobacter and Rhodobacter. Numerous biochemical and physiological features also supported the distinctiveness of the isolates from previously known species. Based on the phenotypic and phylogenetic data presented in this study, three novel species are suggested with the following names: Massilia litorea sp. nov. (LPB0304T=KACC 21523T=ATCC TSD-216T), Marinobacter salinisoli sp. nov. (LPB0319T=KACC 21522T=ATCC TSD-218T) and Rhodobacter xanthinilyticus sp. nov. (LPB0142T=KACC 18892T=JCM 31567T).

Peripheral blood transcriptomic clusters uncovered immune phenotypes of asthma.

BACKGROUND: Transcriptomic analysis has been used to elucidate the complex pathogenesis of heterogeneous disease and may also contribute to identify potential therapeutic targets by delineating the hub genes. This study aimed to investigate whether blood transcriptomic clustering can distinguish clinical and immune phenotypes of asthmatics, and microbiome in asthmatics. METHODS: Transcriptomic expression of peripheral blood mononuclear cells (PBMCs) from 47 asthmatics and 21 non-asthmatics was measured using RNA sequencing. A hierarchical clustering algorithm was used to classify asthmatics. Differentially expressed genes, clinical phenotypes, immune phenotypes, and microbiome of each transcriptomic cluster were assessed. RESULTS: In asthmatics, three distinct transcriptomic clusters with numerously different transcriptomic expressions were identified. The proportion of severe asthmatics was highest in cluster 3 as 73.3%, followed by cluster 2 (45.5%) and cluster 1 (28.6%). While cluster 1 represented clinically non-severe T2 asthma, cluster 3 tended to include severe non-T2 asthma. Cluster 2 had features of both T2 and non-T2 asthmatics characterized by the highest serum IgE level and neutrophil-dominant sputum cell population. Compared to non-asthmatics, cluster 1 showed higher CCL23 and IL1RL1 expression while the expression of TREML4 was suppressed in cluster 3. CTSD and ALDH2 showed a significant positive linear relationship across three clusters in the order of cluster 1 to 3. No significant differences in the diversities of lung and gut microbiomes were observed among transcriptomic clusters of asthmatics and non-asthmatics. However, our study has limitations in that small sample size data were analyzed with unmeasured confounding factors and causal relationships or function pathways were not verified. CONCLUSIONS: Genetic clustering based on the blood transcriptome may provide novel immunological insight, which can be biomarkers of asthma immune phenotypes. Trial registration Retrospectively registered.

Effect of luxS encoding a synthase of quorum-sensing signal molecule AI-2 of Vibrio vulnificus on mouse gut microbiome.

Autoinducer-2 (AI-2), a quorum-sensing signal molecule from the human pathogen Vibrio vulnificus, was assessed for its effect on the gut microbiome of mice. For this, we employed 16S rRNA sequencing to compare the gut microbiome of mice infected with either wild-type V. vulnificus or with the isotype ΔluxS that has a deletion in luxS which encodes the biosynthetic function of AI-2. The relative ratio of wild-type Vibrio species in the jejunum and ileum of mice infected with the wild type was significantly higher than that in mice infected with ΔluxS, suggesting that AI-2 plays an important role in the colonization of V. vulnificus in the small intestine. The bacterial composition in the gut of mice infected with ΔluxS comprises a higher proportion of Firmicutes, composed mainly of Lactobacillus, compared to the mice infected with wild-type cells. In the large intestine, Vibrio species were barely detected regardless of genetic background. Three Lactobacillus spp. isolated from fecal samples from mice infected with ΔluxS manifested significant antibacterial activities against V. vulnificus. Culture supernatants from these three species were dissolved by HPLC, and a substance in fractions showing inhibitory activity against V. vulnificus was determined to be lactic acid. Our results suggest that luxS in V. vulnificus affects not only the ability of the species to colonize the host gut but also its susceptibility to the growth-inhibiting activity of commensal bacteria including Lactobacillus. KEY POINTS: • Gut microbiomes of ΔluxS-infected and WT Vibrio-infected mice differed greatly. • Difference was most prominent in the jejunum and ileum compared to the duodenum or large intestine. • In the small and large intestines of mice, the relative proportions of Vibrio and Lactobacillus species showed a negative relationship. • Effector molecules produced by Lactobacillus in mouse gut inhibit Vibrio growth.

Lung virome: New potential biomarkers for asthma severity and exacerbation.

BACKGROUND: Although some respiratory virus infections are known to contribute to the development and exacerbation of asthma, commensal viromes in airway have not been extensively studied due to technical challenges. OBJECTIVES: This study investigated the characteristics of the virome in asthmatic airways. METHODS: Both the bacteriome and virome profiles in sputum from 12 healthy individuals, 15 patients with nonsevere asthma, and 15 patients with severe asthma were analyzed and assessed for the association with clinical characteristics such as severity, exacerbation, Asthma Control Test (ACT), and lung function. RESULTS: While analysis of the 16S ribosomal RNA bacteriome in the airway showed no differences, clear contrasts in the diversity and composition of airway viromes were observed between healthy controls and patients with asthma. Herpesviruses were the most abundant type of virus in the asthma group (44.6 ± 4.6%), mainly with cytomegalovirus (CMV) and EBV accounting for 24.5 ± 3.3% and 16.9 ± 3.5%, respectively, in contrast to those in the healthy controls (5.4 ± 2.5% and 7.1 ± 3.0%, respectively). CMV and EBV were more abundant in patients with asthma who experienced exacerbation, and their abundance showed correlation with more severe asthma, lower ACT score, and lower lung function. On the contrary, bacteriophage that is abundant in healthy controls was severely reduced in patients with asthma in the order of nonsevere and severe asthma and presented significant positive correlation with ACT and FEV1/forced vital capacity. CONCLUSIONS: Lung viromes, especially, CMV, EBV, and bacteriophage may be potential biomarkers of asthma severity and exacerbation.

Poseidonibacter parvus sp. nov., isolated from a squid.

A Gram-stain-negative, aerobic, short rod-shaped, motile, brownish-coloured bacterium, termed strain LPB0137T, was isolated from a squid. Its cells could grow weakly on marine agar 2216 with 0.04 % 2,3,5-triphenyl tetrazolium chloride (TTC). Each cell of strain LPB0137T has a circular chromosome with a length of 2.87 Mb and 27.7 mol% DNA G+C content. The genome includes 2698 protein-coding genes and six rRNA operons. In 16S rRNA gene sequence trees, strain LPB0137T formed a robust monophyletic clade with Poseidonibacter antarcticus SM1702T with a sequence similarity of 98.3 %. However, the average nucleotide identity and in silico DNA-DNA hybridization values between the two type strains were low (83.9 and 28.1 %, respectively). The overall phenotypic and genomic features of strain LPB0137T supported its assignment to the genus Poseidonibacter. However, the relatively low gene and genome sequence similarity between this strain and other type strains of the genus Poseidonibacter and several enzymatic characteristics indicated the taxonomic novelty of the isolated strain as a new member of the genus Poseidonibacter. Therefore, based on the phylogenetic and phenotypic characteristics of LPB0137T, we proposed a novel species of the genus Poseidonibacter for it, with the name Poseidonibacter parvus sp. nov. The type strain of this new species is thus LPB0137T (=KACC 18888T=JCM 31548T).

Respiratory microbiome profiles differ by recent hospitalization and nursing home residence in patients on mechanical ventilation.

BACKGROUND: Healthcare-associated pneumonia (HCAP) is a heterogeneous disease. We redefined nursing-home- and hospital-associated infections (NHAI) group by revising existing HCAP risk factors. The NHAI group comprised nursing home residents with a poor functional status, or recent (past 90 days) hospitalization or recent (past 180 days) antibiotic therapy. Our aim was to determine whether respiratory microbiota profiles are related to newly defined NHAI group in critically ill patients on mechanical ventilation. METHODS: The 180 endotracheal aspirates (ETAs) from 60 mechanically ventilated ICU patients (NHAI group, n = 24; non-NHAI group, n = 36) were prospectively collected on days 1, 3 and 7 in a university hospital. The bacterial community profiles of the ETAs were explored by 16S rRNA gene sequencing. A phylogenetic-tree-based microbiome association test (TMAT), generalized linear mixed models (GLMMs), the Wilcoxon test and the reference frame method were used to analyze the association between microbiome abundance and disease phenotype. RESULTS: The relative abundance of the genus Corynebacterium was significantly higher in the pneumonia than in the non-pneumonia group. The microbiome analysis revealed significantly lower α-diversity in the NHAI group than in the non-NHAI group. In the analysis of ß-diversity, the structure of the microbiome also differed significantly between the two groups (weighted UniFrac distance, Adonis, p < 0.001). The abundance of Corynebacterium was significantly higher, and the relative abundances of Granulicatella, Staphylococcus, Streptococcus and Veillonella were significantly lower, in the NHAI group than in the non-NHAI group. CONCLUSIONS: The microbiota signature of the ETAs distinguished between patients with and without risk factors for NHAI. The lung microbiome may serve as a therapeutic target for NHAI group.

Urechidicola croceus gen. nov., sp. nov., a member of the family Flavobacteriaceae.

A Gram-stain-negative, rod-shaped, non-flagellated, non-gliding, aerobic bacterial strain, designated LPB0138T, was isolated from a marine spoon worm (Urechis unicinctus). The strain LPB0138T contains a circular chromosome of 3.43 Mb with a DNA G+C content of 30.4 mol%. The genome includes 2987 protein-coding genes and two copies of rRNA operons. The 16S rRNA gene sequence analysis showed that the isolate occurred within a clade containing only members of the family Flavobacteriaceae. The highest sequence similarity was observed with the genus Lutibacter (93.0-94.3 %), but the phylogenetic leaf of the new isolate did not belong to any of the genera known in the family Flavobacteriaceae. The low sequence similarity and the phylogenetic tree topology implied the novel generic status of the new isolate. The phenotypic properties of the strain LPB0138T also differentiated this isolate from its neighbour genera by showing a distinctive fatty acid composition, unique polar lipids profile, and low DNA G+C content. The LPB0138T strain contained menaquinone 6 as the isoprenoid quinone; iso-C15 : 1 G, iso-C15 : 0, iso-C15 : 0 3-OH, and iso-C17 : 0 3-OH as the major fatty acids; and phosphatidylethanolamine, unidentified aminophospholipids, unidentified aminolipids, and unidentified lipids as the major polar lipids. Based on the polyphasic taxonomic data obtained, the LPB0138T strain is considered to represent a novel species in a novel genus of the family Flavobacteriaceae, for which the name Urechidicola croceus gen. nov., sp. nov. was proposed. The type strain is LPB0138T (=KACC 18889T;=JCM 31563T).

Mucilaginibacter celer sp. nov. and Aquirhabdus parva gen. nov., sp. nov., isolated from freshwater.

Two novel bacteria, designated HYN0043T and HYN0046T, were isolated from a freshwater lake in Korea. 16S rRNA gene sequence phylogeny indicated that strain HYN0043T belongs to the genus Mucilaginibacter of the family Sphingobacteriaceae because it showed highest sequence similarity to Mucilaginibacter oryzae (98.2 %). The average nucleotide identity between strain HYN0043T and M. oryzae was 83.5 %, which is clearly below the suggested threshold for species demarcation. Strain HYN0046T was found to belong to the family Moraxellaceae and shared highest sequence similarity with Agitococcus lubricus (93.8 %). The average amino acid identity values between strain HYN0046T and representative type strains of closely related genera (Alkanindiges, Agitococcus and Acinetobacter) were 53.1-60.7 %, implying the novelty of the isolate at the genus level. Phenotypic characteristics (physiological, biochemical and chemotaxonomic) also supported the taxonomic novelty of the two isolates. Thus, we suggest the following names to accommodate strains HYN0043T and HYN0046T: Mucilaginibacter celer sp. nov. (type strain HYN0043T=KACC 19184T=NBRC 112738T) in the family Spingobacteriaceae and phylum Bacteroidetes and Aquirhabdus parva gen. nov., sp. nov. (type strain HYN0046T=KACC 19178T=NBRC 112739T) in the family Moraxellaceae and phylum Proteobacteria.

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).

Pseudomonas neustonica sp. nov., isolated from the sea surface microlayer of the Ross Sea (Antarctica).

Gram-stain-negative, aerobic and rod-shaped bacterial strains, designated SSM26T and SSM44, were isolated from a sea surface microlayer sample from the Ross Sea, Antarctica. Analysis of the 16S rRNA gene sequences of strains SSM26T and SSM44 revealed a clear affiliation with the genus Pseudomonas. Based on the results of phylogenetic analysis, strains SSM26T and SSM44 showed the closest phylogenetic relationship with the species Pseudomonas sabulinigri KCTC 22137T with the 16S rRNA gene sequence similarity level of 98.5 %. Strains SSM26T and SSM44 grew optimally at 30 °C, pH 7.0-7.5 and 0.5-10.0 % NaCl (w/v). The major cellular fatty acids were C18 : 1 ω7c (31.3-34.9 %), C16 : 0 (15.5-20.2 %), summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c; 19.5-25.4 %) and C12 : 0 (6.0-9.3 %). The genomic DNA G+C content of each strain was 56.2 mol%. Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strains SSM26T and SSM44 constituted a single species that was clearly distinguishable from its phylogenetically close relatives. The combined phenotypic, chemotaxonomic, genomic and phylogenetic data also showed that strains SSM26T and SSM44 could be distinguished from validly published members of the genus Pseudomonas. Thus, these strains should be classified as representing a novel species in the genus Pseudomonas, for which the name Pseudomonas neustonica sp. nov. is proposed with the type strain SSM26T (=KCCM 43193T=JCM 31284T=PAMC 28426T) and a sister strain SSM44 (=KCCM 43194=JCM 31285=PAMC 28427).

Limnobaculum parvum gen. nov., sp. nov., isolated from a freshwater lake.

A Gram-stain-negative, rod-shaped, facultatively anaerobic bacterium, designated as strain HYN0051T, was isolated from lake water. 16S rRNA gene sequence analyses indicated that the isolate shares the highest sequence similarity with the genus Pragia (97.1 %) of the family Enterobacteriaceae. Strain HYN0051T did not form a rigid clade with the genus Pragia in any of the phylogenetic trees, demonstrating the novel generic status of the isolate. The genome of strain HYN0051T (CP029185) is a single circular chromosome of 3.84 Mb. The major fatty acids detected were C14 : 0, C16 : 0, summed feature 2 (C12 : 0 aldehyde and/or unknown 10.928), summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The isoprenoid quinones were Q-8, MK-8 and DMK-8. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine and one unidentified phospholipid. The genome size, G+C content and fatty acid profile were very similar to that of the genus Pragia, but the composition of isoprenoid quinones and polar lipids, and numerous phenotypic properties also supported the distinctiveness of the new isolate from the genus Pragia. Thus, based on phylogenetic and phenotypic data, a novel species of a new genus, Limnobaculum parvum gen. nov., sp. nov., is proposed. The type strain of Limnobaculum parvum is HYN0051T (=KACC 19186T=NBRC 112742T).

Phenylobacterium parvum sp. nov., isolated from lake water.

A Gram-stain-negative, rod-shaped and aerobic bacterium, designated HYN0004T, was isolated from lake water. The strain grew at 15-35 °C and pH 7.0-9.0 on R2A. The isoprenoid quinone was Q10 and major polar lipids were phosphatidylglycerol and one unidentified glycolipid. The genome was 2.83 Mb with a DNA G+C content of 69.9 mol%. 16S rRNA gene sequence analyses revealed that HYN0004T represented a member of the genus Phenylobacterium and shared sequence similarities with Phenylobacterium conjunctum (97.8 %), Phenylobacterium koreense (97.5 %), Phenylobacterium aquaticum (97.2 %), and Phenylobacteriumheamatophilum (97.0 %). In addition to the low sequence similarities, the phylogenetic tree shapes indicated that HYN0004Trepresents an independent species of this genus. The genomic and phenotypic properties, including small genome size, inability to carry out numerous enzymatic reactions and high ratio of C18 : 1ω6c and/or C18 : 1ω7c in fatty acids, verified the differentiation between HYN0004T and related species. Thus, we propose a novel species of the genus Phenylobacterium, named as Phenylobacterium parvum sp. nov. The type strain is HYN0004T (=KACC 19185T=NBRC 112736T).

Sphingorhabdus lutea sp. nov., isolated from sea water.

A Gram-stain-negative, yellow-pigmented, aerobic bacterial strain, designated LPB0140T, was isolated from sea water. The 16S rRNA gene sequence similarity analysis demonstrated that the closest relative of the isolate is Sphingorhabdus contaminans (96.4 %), but the new isolate formed an independent phyletic line within the genus Sphingorhabdus. Its genome is composed of a circular chromosome of 2.53 Mb with DNA G+C content of 46.1 mol%. The genome includes 2359 protein-coding genes, and two copies of rRNA operons. Strain LPB0140T possessed C14 : 0 2-OH, C16 : 1ω7c and/or C16 : 1ω6c, and C18 : 1ω7c and/or C18 : 1ω6c as the major cellular fatty acids and Q-10 as the isoprenoid quinone. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, and sphingoglycolipid, but phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine were also detected as minor polar lipids. The chemotaxonomic properties and enzymatic activities of the novel isolate clearly differed from those of its closest relatives. Thus, based on the phylogenetic and phenotypic data presented in this study, strain LPB0140T should be classified as a novel species in the genus Sphingorhabdus. The type strain is LPB0140T (=KACC18891T=JCM31568T).

Cohnella candidum sp. nov., radiation-resistant bacterium from soil.

A Gram-stain positive, endospore-forming, circular, convex, cream colored, designated strain 18JY8-7T, was isolated from soil collected in Jeju Island, South Korea. Phylogenetic analysis using 16S rRNA gene sequences showed that strain 18JY8-7T formed a distinct lineage within the family Paenibacillaceae (order Bacillales, class Bacilli), and is closely related to Cohnella rhizosphaerae (96.1%, sequence similarity) and Cohnella xylanilytica (96.0%). Optimal growth occurred at 30 °C, pH 6.5 and in the absence of NaCl. The predominant cellular fatty acids were anteiso-C15:0 and iso-C16:0. The major respiratory quinone was MK-7. The polar lipids profile comprised of diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The DNA G + C content was 57.0 mol %. The genotypic and phenotypic analyses revealed the differentiation of strain 18JY8-7T from all recognized Cohenella species. The strain 18JY8-7T, therefore represents a novel bacterial species within the family Paenibacillaceae, for which the name Cohnella candidum sp. nov. is proposed. The type strain is 18JY8-7T (= KCTC 33969T = JCM 33199T).

Flavisolibacter galbus sp. nov., isolated from soil in Jeju Island.

A Gram-stain negative, non-motile, and yellow-coloured bacterium, designated 17J28-26T, was isolated from soil in Jeju Island, Korea. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 17J28-26T formed a distinct lineage within the family Chitinophagaceae (order Chitinophagales, class Chitinophagia), and is closely related to Flavisolibacter ginsenosidimutans (96.8% 16S rRNA gene sequence similarity), and Flavisolibacter ginsengisoli (96.6%). Growth was observed at 18-37 °C (optimum 30 °C) in R2A medium at pH 7.0. The major cellular fatty acids of strain 17J28-26T were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), and iso-C15:0. The predominant respiratory quinone was MK-7. The major polar lipid was identified as phosphatidylethanolamine. Based on biochemical, chemotaxonomic and phylogenetic characteristics, strain 17J28-26T represents a novel bacterial species within the family Chitinophagaceae, for which the name Flavisolibacter galbus sp. nov. is proposed. The type strain of Flavisolibacter galbus is 17J28-26T (= KCTC 62222T = JCM 33203T).

Flavobacterium magnum sp. nov., Flavobacterium pallidum sp. nov., Flavobacterium crocinum sp. nov. and Flavobacterium album sp. nov.

Four new limnic bacterial strains, namely HYN0048T, HYN0049T, HYN0056T and HYN0059T, were isolated from two lakes in the Nakdong River water system in Korea. 16S rRNA gene sequence analyses indicated that strains HYN0048T, HYN0049T, HYN0056T and HYN0059T belonged to the genus Flavobacterium by showing the highest sequence similarities with the type strains of F. soli (94.9 %), F. keumense (95.1 %), F. dispersum (97.7 %) and F. hauense (97.6 %), respectively. The low sequence similarities and tree topologies implied the novelty of the four isolates, as novel genomic species of the genus Flavobacterium. Numerous physiological and biochemical features also supported the distinctiveness of the isolates from previously known bacterial species. On the basis of the phylogenetic and phenotypic data presented in this study, four novel species are suggested with the following names: Flavobacterium magnum sp. nov. (type strain HYN0048T=KACC 19180T=NBRC 112740T), Flavobacterium pallidum sp. nov. (HYN0049T=KACC 19181T=NBRC 112741T), Flavobacterium crocinum sp. nov. (HYN0056T=KACC 19182T=NBRC 112743T) and Flavobacterium album sp. nov. (HYN0059T=KACC 19183T=NBRC 112744T).

Tenacibaculum todarodis sp. nov., isolated from a squid.

A Gram-stain-negative, rod-shaped, aerobic bacterial strain, designated LPB0136T, was isolated from a squid Todarodes pacificus, caught in the East Sea, off Korea. LPB0136T contained a circular chromosome of 3.02 Mb with a DNA G+C content of 30.7 mol%. The genome included 2726 protein-coding genes and three copies of rRNA operons. Phylogenetic analysis of the 16S rRNA gene sequence indicated that this isolate represents a member of the genus Tenacibaculum with an independent genomic species status, showing sequence similarities of 95.9 % to Tenacibaculum aestuarii SMK-4T and Tenacibaculum caenipelagi HJ-26MT. The detected respiratory quinone (MK-6) and major polar lipid (phosphatidylethanolamine) were similar to the chemotaxonomic profile of other species of the genus Tenacibaculum. The major cellular fatty acids profile (iso-C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 0G) was also similar to those of members of genus Tenacibaculum, but the contents and amounts differed from those of closely related neighbours. Many biochemical and physiological characteristics also distinguished the isolate from other species within the genus Tenacibaculum. On the basis of the pholyphasic taxonomic data determined in this study, strain LPB0136T represents a novel species of the genus Tenacibaculum, for which the name Tenacibaculum todarodis sp. nov. is proposed. The type strain is LPB0136T (=KACC 18887T=JCM 31564T).

Paenibacillus crassostreae sp. nov., isolated from the Pacific oyster Crassostrea gigas.

A Gram-stain-positive, endospore-forming, rod-shaped, aerobic bacterium, designated LPB0068T, was isolated from a Pacific oyster (Crassostrea gigas) in Korea. This isolate was found to share the highest 16S rRNA gene sequence similarity with Paenibacillus macquariensis subsp. macquariensis DSM 2T (98.1 %) and Paenibacillus macquariensis subsp. defensor JCM 14954T (98.0 %). To establish the genomic relatedness of this isolate to its phylogenetic neighbours, its genome sequence and those of Paenibacillus antarcticus CECT 5836T, P. macquariensis subsp. macquariensis DSM 2T, P. macquariensis subsp. defensor JCM 14954T, and Paenibacillus glacialis DSM 22343T were determined. The low average nucleotide identity and digital DNA-DNA hybridization values exhibited by LPB0068T in relation to the other strains in this analysis revealed that it is distinct from other Paenibacillus species. The genome of strain LPB0068T consists of one chromosome and three circular plasmids, and had a DNA G+C content of 40.0 mol%. The major respiratory quinone was menaquinone-7 and the diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified glycolipid, and two unidentified polar lipids. The major cellular fatty acids were anteiso-C15 : 0, C14 : 0, and C16 : 0. Based on genomic, phylogenetic, and phenotypic characteristics, this strain was clearly distinguished from other Paenibacillus species with validly published names and should therefore be classified as a novel species of the genus. The name Paenibacillus crassostreae sp. nov. is proposed, the type strain of which is LPB0068T (=KACC 18694T=JCM 31183T).

Gramella salexigens sp. nov., isolated from seawater.

A Gram-stain-negative, rod-shaped, aerobic bacterial strain, designated LPB0144T was isolated from the seawater of South Sea, Korea. The 16S rRNA gene sequence was found to share the highest sequence similarity to Gramella sediminilitoris GHTF-27T (97.7 %) and the strain branched within the radiation of the genus Gramella in phylogenetic trees. Thus, the taxonomic position of the novel isolate was investigated using a polyphasic approach and complete genome sequencing. Strain LPB0144T has a circular chromosome of 2.98 Mb with DNA G+C content of 38.2 mol%. The genome includes 2604 protein-coding genes and three copies of rRNA operons. The detected respiratory quinone (MK-6) and the major polar lipid (phosphatidylethanolamine) resemble the chemotaxonomic profile of other Gramella species. The major cellular fatty acid profile (iso-C15 : 0, iso-C16 : 0, iso-C17 : 0 3-OH and anteiso-C15 : 0) is also within the range of Gramella, but detailed composition and amounts were found to be different from those of closely related neighbours. Many biochemical and physiological characteristics also distinguished the isolate from other species within the genus Gramella. On the basis of polyphasic taxonomic data obtained here, we propose strain LPB0144T as a novel Gramella species, for which the name Gramella salexigens sp. nov. is proposed. The type strain is LPB0144T (=KACC 18894T=JCM 31560T).