Veillonella faecalis sp. nov., a propionic acid-producing bacterium isolated from the faeces of an infant.

A strictly anaerobic, Gram-stain-negative, catalase-negative, cocci-shaped, and propionate-producing bacterial strain, named Ds1651T was isolated from the fecal sample collected from a South Korean infant. Through a comparison of 16S rRNA gene sequences, it was revealed that Ds1651T had the highest phylogenetic affinity with Veillonella nakazawae KCTC 25297 T (99.86%), followed by Veillonella infantium KCTC 25370 T (99.80%), and Veillonella dispar KCTC 25309 T (99.73%) in the family Veillonellaceae. Average nucleotide identity values between Ds1651T and three reference species were 95.48% for Veillonella nakazawae KCTC 25297 T, 94.46% for Veillonella infantium KCTC 25370 T, and 92.81% for Veillonella dispar KCTC 25309 T. The G + C content of Ds1651T was 38.58 mol%. Major fermentation end-products were acetic and propionic acids in Trypticase peptone glucose yeast extract broth with 1% (v/v) sodium lactate. The predominant cellular fatty acids that account for more than 10% were summed in Feature 8 (C17:1 ω8c and/or C17:2) and C13:0. Based on the findings from phylogenetic, genomic, phenotypic, and chemotaxonomic studies, we propose that the type strain Ds1651T (= KCTC 25477 T = GDMCC 1.3707 T) represents a novel bacterial species within the genus Veillonella, with the proposed name Veillonella faecalis sp. nov.

Maturation of human intestinal organoids in vitro facilitates colonization by commensal lactobacilli by reinforcing the mucus layer.

Lactobacilli, which are probiotic commensal bacteria that mainly reside in the human small intestine, have attracted attention for their ability to exert health-promoting effects and beneficially modulate host immunity. However, host epithelial-commensal bacterial interactions are still largely unexplored because of limited access to human small intestinal tissues. Recently, we described an in vitro maturation technique for generating adult-like, mature human intestinal organoids (hIOs) from human pluripotent stem cells (hPSCs) that closely resemble the in vivo tissue structure and cellular diversity. Here, we established an in vitro human model to study the response to colonization by commensal bacteria using luminal microinjection into mature hIOs, allowing for the direct examination of epithelial-bacterial interactions. Lactobacillus reuteri and Lactobacillus plantarum were more likely to survive and colonize when microinjected into the lumen of mature hIOs than when injected into immature hIOs, as determined by scanning electron microscopy, colony formation assay, immunofluorescence, and real-time imaging with L plantarum expressing red fluorescent protein. The improved mature hIO-based host epithelium system resulted from enhanced intestinal epithelial integrity via upregulation of mucus secretion and tight junction proteins. Our study indicates that mature hIOs are a physiologically relevant in vitro model system for studying commensal microorganisms.

Targeted knockout of a chemokine-like gene increases anxiety and fear responses.

Emotional responses, such as fear and anxiety, are fundamentally important behavioral phenomena with strong fitness components in most animal species. Anxiety-related disorders continue to represent a major unmet medical need in our society, mostly because we still do not fully understand the mechanisms of these diseases. Animal models may speed up discovery of these mechanisms. The zebrafish is a highly promising model organism in this field. Here, we report the identification of a chemokine-like gene family, samdori (sam), and present functional characterization of one of its members, sam2 We show exclusive mRNA expression of sam2 in the CNS, predominantly in the dorsal habenula, telencephalon, and hypothalamus. We found knockout (KO) zebrafish to exhibit altered anxiety-related responses in the tank, scototaxis and shoaling assays, and increased crh mRNA expression in their hypothalamus compared with wild-type fish. To investigate generalizability of our findings to mammals, we developed a Sam2 KO mouse and compared it to wild-type littermates. Consistent with zebrafish findings, homozygous KO mice exhibited signs of elevated anxiety. We also found bath application of purified SAM2 protein to increase inhibitory postsynaptic transmission onto CRH neurons of the paraventricular nucleus. Finally, we identified a human homolog of SAM2, and were able to refine a candidate gene region encompassing SAM2, among 21 annotated genes, which is associated with intellectual disability and autism spectrum disorder in the 12q14.1 deletion syndrome. Taken together, these results suggest a crucial and evolutionarily conserved role of sam2 in regulating mechanisms associated with anxiety.

Lactococcus kimchii sp. nov., a new lactic acid bacterium isolated from kimchi.

A coccus strain designated S-13T was isolated from commercial baechu-kimchi in Korea. Comparison of the 16S rRNA gene sequence indicated that strain S-13T had the highest similarity to Lactococcus taiwanensis 0905C15T (97.9 %), Lactococcus lactis subsp. tructae L105T (97.6 %), Lactococcus lactis subsp. cremoris NCDO 607T (97.5 %), Lactococcus lactis subsp. hordniae NBRC 100931T (97.2 %), and Lactococcus lactis subsp. lactis JCM 5805T (97.2 %). The detailed phylogenetic analyses based on the 16S rRNA, rpoB and recA genes indicated that S-13T was separated from the other species and subspecies in the genus Lactococcus. The DNA-DNA relatedness between S-13T and closely related type strains, such as L. taiwanensis 0905C15T, L. lactis subsp. tructae L105T, L. lactis subsp. cremoris NCDO 607T, L. lactis subsp. hordniae NBRC 100931T, and L. lactis subsp. lactis JCM 5805T was 25.6, 20.4, 25.1, 20.2 and 21.7 %, respectively. The major fatty acids were C16 : 0, cyclo-C19 : 0ω8c and C 14 : 0. The DNA G+C content of S-13T was 39.4 mol%. From the results of the phenotypic characteristics and chemotaxonomic analysis, it was concluded that strain S-13T represents a novel species in the genus Lactococcus for which the name Lactococcus kimchii sp. nov. (=KCTC 21096T=NBRC 113348T) is proposed.

Thermomonas aquatica sp. nov., isolated from an industrial wastewater treatment plant.

A white-coloured, Gram-stain-negative, aerobic, rod-shaped bacterium (designated strain SY21T) was isolated from waste-activated sludge. Optimal growth occurred at 28 °C and pH 7.0. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain SY21T exhibited 16S rRNA gene sequence similarities of 95.5-98.0 % to Thermomonas species and clustered with the type species of the genus Thermomonas. In strain SY21T, the predominant respiratory quinone was ubiquinone Q-8, and the cellular fatty acids consisted mainly of iso-C15 : 0, C16 : 0, iso-C11 : 0 3-OH, summed feature 3 and summed feature 9. The major polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was determined to be 67.9 mol% and the DNA-DNA relatedness between strain SY21T and the closest phylogenetically related strain, Thermomonas carbonis KCTC 42013T, was 35.0±0.1 %. Based on the distinct phenotypic, chemotaxonomic and phylogenetic properties, strain SY21T represents a novel species of the genus Thermomonas, for which the name Thermomonas aquatica sp. nov. is proposed. The type strain is SY21T (=KCTC 62191T=NBRC 113114T).

Lactobacillus porci sp. nov., isolated from small intestine of a swine.

A facultatively anaerobic, Gram-stain-positive, catalase-negative, rod-shaped lactic acid bacterium, designated SG816T, was isolated from small intestine of a swine. Optimal growth occurred at 37 °C and pH 7.0. Furthermore, growth occurred in NaCl up to 0.5 % (w/v) but not at levels of salinity higher than 1 %. Comparative 16S rRNA gene sequencing and the matrix-associated laser desorption/ionization-time-of-flight mass spectometry profiling showed that strain SG816T was closely related to Lactobacillus delbrueckiisubsp. bulgaricus KCTC 3635T (95.9 %) and Lactobacillus delbrueckiisubsp. indicus JCM 15610T (95.9 %), followed by other Lactobacillus delbrueckii subspecies (95.9-95.7 %) and Lactobacillus equicursoris DSM 19284T (95.6 %). A comparison of two housekeeping genes, RNA polymerase alpha subunit (rpoA) and phenylalanyl-tRNA synthase alpha subunit (pheS), revealed that strain SG816T formed a separate branch within the clade of the genus Lactobacillus. The DNA G+C content level of the strain SG816T was 51.5 mol%. The strain was homofermentative and produced d-lactic acid from glucose fermentation. The major cellular fatty acids (>10 %) of the isolate were C18 : 1ω9c and C16 : 0. The peptidoglycan type was A4α l-Lys-d-Asp. On the basis of distinct phenotypic and phylogenetic properties, strain SG816T represents a novel species of the genus Lactobacillus, for which the name Lactobacillus porci sp. nov. is proposed. The type strain is SG816T (=KCTC 21090T=NBRC 112917T).

Tabrizicola fusiformis sp. nov., isolated from an industrial wastewater treatment plant.

The translucent white-coloured, Gram-stain-negative, aerobic, non-motile, fusiform-shaped bacterium (designated strain SY72T) was isolated from waste-activated sludge. Optimal growth occurred at 30-37 °C and pH 6.0-7.0. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the novel isolate belonged to the family Rhodobacteraceae of the class Alphaproteobacteria. Strain SY72T is closely related to Tabrizicola aquatica KCTC 23724T (97.8 % 16S rRNA gene sequence similarity) and Pseudorhodobacter aquaticus DC2N1-10T (96.4 %), respectively. DNA-DNA relatedness between strain SY72T and the closest phylogenetically related strain, Tabrizicola aquatica KCTC 23724T, was 18.0±0.7 %. In strain SY72T, the predominant respiratory quinone was ubiquinone Q-10, and the cellular fatty acids consisted mainly of C18 : 1ω7c and C18 : 1ω7c-11 methyl. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. Photoautotrophic and photoheterotrophic growth did not occur in strain SY72T. Furthermore, strain SY72T did not produce photosynthetic pigments or contain the photosynthetic genes pufL and pufM, by which it differed from the phototrophic species of the family Rhodobacteraceae. On the basis of distinct phenotypic and phylogenetic properties, strain SY72T represents a novel species of the genus Tabrizicola, for which the name Tabrizicola fusiformis sp. nov. is proposed. The type strain is SY72T (=KCTC 62105T=NBRC 113021T).

Species-Specific Interactions between Plant Metabolites and Insect Juvenile Hormone Receptors.

Because juvenile hormone (JH) controls insect development and its analogs are used as insecticides, juvenile hormone disruptors (JHDs) represent potential sources from which novel pesticides can be developed. Many plant species harbor JHD activity, which has previously been attributed plant secondary metabolites (i.e., diterpenes) that disrupt insect development by interfering with the JH-mediated heterodimer formation of insect juvenile receptor complexes. The results of the present study indicate that plant JHD activity is also concentrated in certain plant groups and families and that plant metabolites have insect group-specific activity. These findings suggest that reciprocal diversification has occurred between plants and insects through the evolution of the plant metabolites and JH receptors, respectively, and that plant metabolites could be developed into insect group-specific pesticides with limited effects on non-target species.

Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides.

Lacinutrix chionocetis sp. nov., isolated from gut of a red snow crab.

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated MAB-07T, was isolated from the gut of a red snow crab. The novel strain grew optimally at 20 °C, pH 7.0-8.0, and in the presence of 3% (w/v) NaCl. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that the strain MAB-07T belongs to the type strains of species of the genus Lacinutrix. Strain MAB-07T exhibited 16S rRNA gene sequence similarity values of 95.5-97.8% with the type strains of species of the genus Lacinutrix. The predominant cellular fatty acids of strain MAB-07T were iso-C15:1 G (27.5%) and iso-C15:0 (21.7%). The major respiratory quinine was identified as MK-6. The polar lipids consisted of phosphatidylethanolamine, four unidentified aminolipids, and two unidentified lipids. The genomic DNA G + C content was determined to be 33.3%, and its DNA-DNA relatedness values with the type strains of L. venerupis, L. mariniflava, L. jangbogonensis, L. algicola, and Olleya aquimaris were 28-32%. Based on the data from this polyphasic taxonomic study, strain MAB-07T is considered to represent a novel species of the genus Lacinutrix, for which the name L. chionocetis sp. nov. is proposed. The type strain is MAB-07T (=KCTC 42767T = JCM 30988T).

Conifer Diterpene Resin Acids Disrupt Juvenile Hormone-Mediated Endocrine Regulation in the Indian Meal Moth Plodia interpunctella.

Diterpene resin acids (DRAs) are important components of oleoresin and greatly contribute to the defense strategies of conifers against herbivorous insects. In the present study, we determined that DRAs function as insect juvenile hormone (JH) antagonists that interfere with the juvenile hormone-mediated binding of the JH receptor Methoprene-tolerant (Met) and steroid receptor coactivator (SRC). Using a yeast two-hybrid system transformed with Met and SRC from the Indian meal moth Plodia interpunctella, we tested the interfering activity of 3704 plant extracts against JH III-mediated Met-SRC binding. Plant extracts from conifers, especially members of the Pinaceae, exhibited strong interfering activity, and four active interfering DRAs (7α-dehydroabietic acid, 7-oxodehydroabietic acid, dehydroabietic acid, and sandaracopimaric acid) were isolated from roots of the Japanese pine Pinus densiflora. The four isolated DRAs, along with abietic acid, disrupted the juvenile hormone-mediated binding of P. interpunctella Met and SRC, although only 7-oxodehydroabietic acid disrupted larval development. These results demonstrate that DRAs may play a defensive role against herbivorous insects via insect endocrine-disrupting activity.

IFT46 plays an essential role in cilia development.

Cilia are microtubule-based structures that project into the extracellular space. Ciliary defects are associated with several human diseases, including polycystic kidney disease, primary ciliary dyskinesia, left-right axis patterning, hydrocephalus and retinal degeneration. However, the genetic and cellular biological control of ciliogenesis remains poorly understood. The IFT46 is one of the highly conserved intraflagellar transport complex B proteins. In zebrafish, ift46 is expressed in various ciliated tissues such as Kupffer׳s vesicle, pronephric ducts, ears and spinal cord. We show that ift46 is localized to the basal body. Knockdown of ift46 gene results in multiple phenotypes associated with various ciliopathies including kidney cysts, pericardial edema and ventral axis curvature. In ift46 morphants, cilia in kidney and spinal canal are shortened and abnormal. Similar ciliary defects are observed in otic vesicles, lateral line hair cells, olfactory pits, but not in Kupffer׳s vesicle. To explore the functions of Ift46 during mouse development, we have generated Ift46 knock-out mice. The Ift46 mutants have developmental defects in brain, neural tube and heart. In particular Ift46(-/-) homozygotes displays randomization of the embryo heart looping, which is a hallmark of defective left-right (L/R) axis patterning. Taken together, our results demonstrated that IFT46 has an essential role in vertebrate ciliary development.

Pseudoalteromonas aestuariivivens sp. nov., isolated from a tidal flat.

A Gram-stain-negative, aerobic, motile, rod-shaped or ovoid bacterial strain, designated DB-2T, was isolated from a tidal flat of the Yellow Sea in South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain DB-2T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain DB-2T belonged to the genus Pseudoalteromonas. Strain DB-2T exhibited 16S rRNA gene sequence similarities of 97.17-97.36 % to the type strains of Pseudoalteromonas mariniglutinosa, Pseudoalteromonas spongiae and Pseudoalteromonas tetraodonis and of 93.79-96.99 % to the type strains of the other species of the genus Pseudoalteromonas. Strain DB-2T contained Q-8 as the predominant ubiquinone and C16 : 0, C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C12 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DB-2T were phosphatidylglycerol, phosphatidylethanolamine, two unidentified glycolipids, an unidentified phospholipid and an unidentified aminolipid. The DNA G+C content of strain DB-2T was 54.9 ± 0.2 mol% and mean DNA-DNA relatedness values with the type strains of P. mariniglutinosa, P. spongiae and P. tetraodonis were 10-17 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-2T is separated from recognized species of the genus Pseudoalteromonas. On the basis of these data, strain DB-2T is considered to represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas aestuariivivens sp. nov. is proposed. The type strain is DB-2T ( = KCTC 42779T = CECT 8945T).

Paracoccus aestuariivivens sp. nov., isolated from a tidal flat.

A Gram-stain-negative, non-spore-forming, non-motile and coccoid, ovoid or short-rod-shaped bacterial strain, designated GHD-30T, was isolated from a tidal flat on the Yellow Sea in South Korea, and subjected to a polyphasic taxonomic study. Strain GHD-30T grew optimally at 30 °C, at pH 6.5-7.5 and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain GHD-30Trepresented a member of the genus Paracoccus. Strain GHD-30T exhibited 16S rRNA gene sequence similarity values of 97.10-97.33 % to the type strains of Paracoccus lutimaris, Paracoccus limosus and Paracoccus halophilus and of 94.35-96.97 % to the type strains of the other species of the genus Paracoccus. Strain GHD-30T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The major polar lipids detected in strain GHD-30T were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminolipid. The DNA G+C content of strain GHD-30T was 62.0 mol% and its mean DNA-DNA relatedness values with the type strains of P. lutimaris, P. limosus, and P. halophilus were 11-19 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GHD-30T is separated from recognized species of the genus Paracoccus. On the basis of the data presented, strain GHD-30T is considered to represent a novel species of the genus Paracoccus, for which the name Paracoccus aestuariivivens sp. nov. is proposed. The type strain is GHD-30T (=KCTC 52214T =NBRC 111993T).

Agathobaculum butyriciproducens gen. nov. sp. nov., a strict anaerobic, butyrate-producing gut bacterium isolated from human faeces and reclassification of Eubacterium desmolans as Agathobaculum desmolans comb. nov.

A novel bacterial strain, SR79T, was isolated from a Korean faecal sample and characterized using a polyphasic approach. SR79T was found to be a strictly anaerobic, Gram-stain-positive, non-spore-forming, non-motile, catalase- and oxidase-negative short rod with no flagella. SR79T grew optimally at 37 °C in the presence of 0.5 % (w/v) NaCl at pH 7. The NaCl range for growth was 0-1 % (w/v). The isolate produced butyric acid (>18 mM) as a major end product. A phylogenetic analysis based on 16S rRNA gene sequences revealed that the most closely related type strains were Eubacteriumdesmolans ATCC 43058T and Butyricicoccus pullicaecorum 25-3T (96.4 and 96.0 % similarity, respectively). The DNA G+C content was determined to be 52.9 mol%. The major cellular fatty acids (>10 %) were C16 : 0, C18 : 1cis-9, C19 : 1 cyc 9,10 and C14 : 0. Meso-diaminopimelic acid was present in the cell wall peptidoglycan and the cell wall hydrolysates contained ribose, glucose and galactose. The 16S rRNA gene sequence similarity, phylogenetic analysis, chemotaxonomic and phenotypic characteristics allowed differentiation of SR79T, which represents a novel species of a new genus within the family Ruminococcaceae, for which the name Agathobaculum butyriciproducens gen. nov. sp. nov. is proposed. The type strain is SR79T (=KCTC 15532T=DSM 100391T). Based on the results of this study, it is also proposed to transfer Eubacteriumdesmolans to this new genus, as Agathobaculum desmolans comb. nov. The type strain of Agathobaculum desmolans is ATCC 43058T (=CCUG 27818T).

Jejuia marina nov., isolated from gravel adjacent to Geommeolle beach on Udo Island, South Korea.

A bacterial strain, JH03(T), was isolated from gravel adjacent to Geommeolle beach on Udo Island, South Korea. The cells were Gram-stain-negative, aerobic, non-motile and rod shaped. The ranges of temperature, pH and NaCl concentration for growth of the bacterium were 10-45 °C, pH 6.0-9.5 and 0.5-5.0 % (w/v), respectively. The major fatty acids of the bacterium were iso-C(15:0) (15.4 %), iso-C(15:1) G (14.1 %), iso-C(16:0) 3-OH (14.1 %), iso-C(17:0) 3-OH (11.5 %) and anteiso-C(15:0) (11.3 %). The major isoprenoid quinone was MK-6. The polar lipids included phosphatidylethanolamine, two unidentified amino lipids and three unidentified lipids. The DNA G+C content was 34.2 mol%. The phylogenetic analysis of the 16S rRNA gene sequences showed that strain JH03(T) was most closely related to Jejuia pallidilutea EM39(T) (96.5 % sequence similarity). Based on the polyphasic analysis, strain JH03(T) is a novel species of the genus Jejuia, for which the name Jejuia marina sp. nov. is proposed. The type strain is JH03(T) (= KCTC 42342(T) = JCM 30601(T)).

Lutibacter crassostreae sp. nov., isolated from oyster.

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated, non-gliding and ovoid or rod-shaped bacterial strain, designated TYO-8T, was isolated from an oyster collected from the South Sea in South Korea. Strain TYO-8T grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. A neighbour-joining phylogenetic tree, based on 16S rRNA gene sequences, revealed that strain TYO-8T fell within the clade comprising the type strains of species of the genus Lutibacter, clustering coherently with the type strain of Lutibacter litoralis with a sequence similarity of 99.3%. Strain TYO-8T exhibited 16S rRNA gene sequence similarity values of 95.3-97.5% to the type strains of other species of the genus Lutibacter and of less than 92.9% to the type strains of other species with validly published names. Strain TYO-8T contained MK-6 as the predominant menaquinone and iso-C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 1 G as the major fatty acids. The major polar lipids of strain TYO-8T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain TYO-8T was 33.8 mol% and its DNA-DNA relatedness values with the type strains of L. litoralis, Lutibacter aestuarii and Lutibacter flavus were 13-27%. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain TYO-8T is distinct from other species of the genus Lutibacter. On the basis of the data presented, strain TYO-8T is considered to represent a novel species of the genus Lutibacter, for which the name Lutibacter crassostreae sp. nov. is proposed. The type strain is TYO-8T ( = KCTC 42461T = NBRC 110923T).

Erysipelothrix larvae sp. nov., isolated from the larval gut of the rhinoceros beetle, Trypoxylus dichotomus (Coleoptera: Scarabaeidae).

A novel, Gram-stain positive, facultative anaerobic, non-motile and straight to curve rod shaped bacterium, strain LV19(T) was isolated from the larval gut of the rhinoceros beetle, Trypoxylus dichotomus, which was collected from Yeong-dong, Chuncheongbuk-do, South Korea. The colonies of the new isolate were convex, circular, cream white in color and 1-2 mm in diameter after 3 days incubation on Tryptic Soy Agar at 37 °C. Based on the 16S rRNA gene sequence similarity, the new isolate was most closely related to Erysipelothrix inopinata MF-EP02(T), E. rhusiopathiae ATCC 19414 (T) and E. tonsillarum T-305(T) (94.8, 93.8 and 93.7 % similarity, respectively). Strain LV19(T) grew optimally at 37 °C, at pH 8.0 and in the presence of 0.5 % (w/v) NaCl. Oxidase activity and catalase activity were negative. The major cellular fatty acids (>10 %) were C18:2 cis-9,12 (28.9 %), C18:1 cis-9 (22.3 %), C16:0 (22.2 %) and C18:0 (18.5 %). The cell-wall hydrolysates contained ribose as a major sugar. Major polar lipids were phosphatidylglycerol and three unidentified glycolipids. No quinone was detected. The G+C content of the genomic DNA was 36.3 mol%. The levels of DNA-DNA relatedness between strain LV19(T) and all the reference strains were less than 20 %. On the basis of polyphasic evidence from this study, the isolate is considered to represent a novel species of the genus Erysipelothrix, for which the name Erysipelothrix larvae sp. nov. is proposed; the type strain is LV19(T) (=KCTC 33523(T) = DSM 28480(T)).

Hyunsoonleella udoensis sp. nov., isolated from a gravel sample from a beach of Udo island, Korea.

A Gram-stain negative, non-motile, rod-shaped and aerobic bacterial strain, designated JG48(T), was isolated from a gravel sample taken from a beach adjacent to Udo island, South Korea. Strain JG48(T) was found to grow optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0 % (w/v) NaCl. The 16S rRNA gene sequence of strain JG48(T) exhibited sequence similarities of 96.67 % to Hyunsoonleella jejuensis CNU004(T). The major fatty acids present in the strain JG48(T) were identified as iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and iso-C15:0 3-OH. The predominant isoprenoid quinone was identified as MK-6. The polar lipids profile of strain JG48(T) was found to consist of phosphatidylethanolamine, three unidentified amino lipids and four unidentified lipids. The DNA G+C content of strain JG48(T) was determined to be 34 mol%. Based on the morphological and physiological properties, and the results of phylogenetic analyses, the strain is considered to represent a novel species of the genus Hyunsoonleella, for which the name Hyunsoonleella udoensis sp. nov. is proposed. The type strain is JG48(T) (=KCTC 42341(T)=JCM 30600(T)).

Insect gut bacterial diversity determined by environmental habitat, diet, developmental stage, and phylogeny of host.

Insects are the most abundant animals on Earth, and the microbiota within their guts play important roles by engaging in beneficial and pathological interactions with these hosts. In this study, we comprehensively characterized insect-associated gut bacteria of 305 individuals belonging to 218 species in 21 taxonomic orders, using 454 pyrosequencing of 16S rRNA genes. In total, 174,374 sequence reads were obtained, identifying 9,301 bacterial operational taxonomic units (OTUs) at the 3% distance level from all samples, with an average of 84.3 (± 97.7) OTUs per sample. The insect gut microbiota were dominated by Proteobacteria (62.1% of the total reads, including 14.1% Wolbachia sequences) and Firmicutes (20.7%). Significant differences were found in the relative abundances of anaerobes in insects and were classified according to the criteria of host environmental habitat, diet, developmental stage, and phylogeny. Gut bacterial diversity was significantly higher in omnivorous insects than in stenophagous (carnivorous and herbivorous) insects. This insect-order-spanning investigation of the gut microbiota provides insights into the relationships between insects and their gut bacterial communities.