Expression of virus-like particles (VLPs) of foot-and-mouth disease virus (FMDV) using Saccharomyces cerevisiae.

We engineered Saccharomyces cerevisiae to express structural proteins of foot-and-mouth disease virus (FMDV) and produce virus-like particles (VLPs). The gene, which encodes four structural capsid proteins (VP0 (VP4 and VP2), VP3, and VP1), followed by a translational "ribosomal skipping" sequence consisting of 2A and protease 3C, was codon-optimized and chemically synthesized. The cloned gene was used to transform S. cerevisiae 2805 strain. Western blot analysis revealed that the polyprotein consisting of VP0, VP3, and VP1 was processed into the discrete capsid proteins. Western blot analysis of 3C confirmed the presence of discrete 3C protein, suggesting that the 2A sequence functioned as a "ribosomal skipping" signal in the yeast for an internal re-initiation of 3C translation from a monocistronic transcript, thereby indicating polyprotein processing by the discrete 3C protease. Moreover, a band corresponding to only VP2, which was known to be non-enzymatically processed from VP0 to both VP4 and VP2 during viral assembly, further validated the assembly of processed capsid proteins into VLPs. Electron microscopy showed the presence of the characteristic icosahedral VLPs. Our results clearly demonstrate that S. cerevisiae processes the viral structural polyprotein using a viral 3C protease and the resulting viral capsid subunits are assembled into virion particles. KEY POINTS: • Ribosomal skipping by self-cleaving FMDV peptide in S. cerevisiae. • Proteolytic processing of a structural polyprotein from a monocistronic transcript. • Assembly of the processed viral capsid proteins into a virus-like particle.

Molecular characteristics of a novel hypovirus from Trichoderma harzianum.

We report a novel mycovirus with a positive-sense single-stranded (+)ss RNA genome, belonging to the family Hypoviridae, infecting Trichoderma harzianum strain M6. The complete genome sequence is 13,813 nucleotides long, excluding the poly(A) tail at the 3' end. Sequence analysis revealed that the genome has a single large open reading frame (ORF) encoding a 4,118-amino-acid polyprotein harboring five conserved motifs of a protease, two conserved domains of a protein of unknown function, an RNA-dependent RNA polymerase, and a helicase. Sequence comparisons revealed that the deduced amino acid sequence of the polyprotein is similar to those of other hypoviruses and is most similar to that of Bipolaris oryzae hypovirus 1 (35.1% identity). Phylogenetic analysis using full-length RdRp and helicase sequences showed that this virus clustered closely with known members of the proposed genus "Alphahypovirus" of the family Hypoviridae. We accordingly designated this novel mycovirus "Trichoderma harzianum hypovirus 2" (ThHV2).

Co-infection of a novel fusagravirus and a partitivirus in a Korean isolate of Rosellinia necatrix KACC40168.

We report here the presence of dsRNA mycoviruses in a Korean isolate of Rosellinia necatrix. A multiple band pattern of double-stranded RNA (dsRNA) from R. necatrix suggested mixed mycovirus infection. Next-generation sequencing analysis of purified dsRNAs indicated the presence of two dsRNA mycoviruses related to the members of families "Fusagraviridae" (proposed) and Partitiviridae. The first dsRNA virus revealed that the complete genome sequence was 8868 bp in size and contained two large open reading frames (ORFs 1 and 2), overlapped by 22 bp containing a canonical (- 1) slippery heptanucelotide sequence of UUUAAAC. The deduced amino acid sequence of ORF1 and ORF2 showed highest similarity to the hypothetical protein and RNA-dependent RNA polymerase (RdRp) of Rosellinia necatrix fusagravirus 3 (RnFGV3). Phylogenetic analysis showed that this dsRNA virus clustered with RnFGV3 and other fusagraviruses. Gene organization, sequence similarity, and phylogenetic analysis indicate that this virus seems to belong to a novel species of "Fusagraviridae", which we have named Rosellinia necatrix fusagravirus 4. The second virus has two dsRNA segments with sizes of 1907 bp and 1918 bp, each of which encoded a single ORF showing highest similarity to the RdRp and capsid protein of known members of Partitiviridae. Evaluation of genome structure, sequence similarity, and phylogeny indicate this to be a new member of the genus Alphapartitivirus in the family Partitiviridae, hereafter designated as Rosellinia necatrix partitivirus 26. This is the first report of the presence of a fusagravirus in an Asian R. necatrix isolate and of its mixed infection with a partitivirus.

Expression of an immunocomplex consisting of Fc fragment fused with a consensus dengue envelope domain III in Saccharomyces cerevisiae.

OBJECTIVES: To explore Saccharomyces cerevisiae as an expression platform for dengue oral immune complex vaccine development. RESULTS: Molecular engineering was applied to create a fusion gene construct (scEDIII-PIGS) consisting of a yeast codon optimized sequence encoding for a synthetic consensus dengue envelope domain III (scEDIII) followed by a modified IgG Fc domain (PIGS). Northern blot showed transcription of the target gene, with a temporal expression pattern similar to those from previous work. Western blot showed assembly of various immune complexes from monomer to hexamer. Partial purification of scEDIII-PIGS was also attempted to demonstrate the feasibility of yeast system for immune complex vaccine development. Approximately 1 mg of scEDIII-PIGS can be produced from 1 l culture. CONCLUSION: This work demonstrated for the first time that various immunocomplex structures of our target protein could be efficiently produced in S. cerevisiae for future application in developing oral and injectable vaccines against various pathogens.

Characterization of a Hypovirus-Regulated Septin Cdc11 Ortholog, CpSep1, from the Chestnut Blight Fungus Cryphonectria parasitica.

We identified a protein spot showing downregulation in the presence of Cryphonectria hypovirus 1 and tannic acid supplementation as a septin subunit with the highest homology to the Aspergillus nidulans aspA gene, an ortholog of the Saccharomyces cerevisiae Cdc11 gene. To analyze the functional role of this septin component (CpSep1), we constructed its null mutant and obtained a total of eight CpSep1-null mutants from 137 transformants. All CpSep1-null mutants showed retarded growth, with fewer aerial mycelia and intense pigmentation on plates of potato dextrose agar supplemented with L-methionine and biotin. When the marginal hyphae were examined, hyperbranching was observed in contrast to the wild type. The inhibition of colonial growth was partially recovered when the CpSep1-null mutants were cultured in the presence of the osmostabilizing sorbitol. Conidia production of the CpSep1-null mutants was significantly increased by at least 10-fold more. Interestingly, the conidial morphology of the CpSep1-null mutants changed to circular in contrast to the typical rod-shaped spores of the wild type, indicating a role of septin in the spore morphology of Cryphonectria parasitica. However, no differences in the germination process were observed. Virulence assays using excised chestnut bark, stromal pustule formation on chestnut stems, and apple inoculation indicated that the CpSep1 gene is important in pathogenicity.

Marinobacterium boryeongense sp. nov., isolated from seawater.

A Gram-stain-negative and strictly aerobic bacterium, designated DMHB-2T, was isolated from a sample of seawater collected off the Yellow Sea coast of the Republic of Korea. Cells were short rods and motile by means of a single polar flagellum. Catalase and oxidase activities were positive. Growth occurred at pH 5.5-10.0 (optimum, pH 6.0), 15-45 °C (optimum, 25 °C) and with 1-9 % NaCl (optimum, 3 %). The respiratory quinone was ubiquinone-8 and the major fatty acids were C16 : 0 (17.9 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 26.1 %) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 37.4 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DMHB-2T belong to the genus Marinobacterium, with the highest 16S rRNA gene sequence similarity of 95.2 % to Marinobacterium zhoushanense KCTC 42782T. The genomic DNA G+C content of strain DMHB-2T was 60.8 mol%. On the basis of the phenotypic, chemotaxonomic and genotypic characteristics presented in this study, strain DMHB-2T is suggested to represent a novel species of the genus Marinobacterium, for which the name Marinobacteriumboryeongense sp. nov. is proposed. The type strain is DMHB-2T (=KACC 19225T=JCM 31902T).

Gemmobacter straminiformis sp. nov., isolated from an artificial fountain.

A Gram-stain-negative, non-motile and facultative anaerobic bacterium, designated CAM-8T, was isolated from an artificial fountain at Chonbuk National University, South Korea. The novel strain grew at 20-37 °C (optimum 25 °C), pH 5.5-7.0 (optimum 6.0) and with 0-2 % NaCl (optimum 0 %). Oxidase and catalase activities were positive. The cell morphology of strain CAM-8T was atypical rods 0.6-0.8 µm in width and 4.5-6.5 µm in length, with a peaked tip and sometimes a bulb shape. CAM-8T existed as single cells, and as pairs or chains of cells. The phylogenetic analysis of 16S rRNA gene sequences indicated that strain CAM-8T clustered with Gemmobacter nectariphilus JCM 11959T and Gemmobactermegaterium JCM 18498T within the genus Gemmobacter. The DNA G+C content of strain CAM-8T was 65.9 mol%. The respiratory quinone was ubiquinone Q-10. The major fatty acids were C18 : 1ω7c and/or C18 : 1ω6c. The polar lipids of strain CAM-8T consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two uncharacterized phospholipids, an uncharacterized aminolipid, an uncharacterized glycolipid, an uncharacterized aminophospholipid and four uncharacterized lipids. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain CAM-8T (=KACC 19224T=JCM 31905T) is considered to represent a novel species of the genus Gemmobacter, for which the name Gemmobacter straminiformis sp. nov. is proposed.

Characterization of a novel dsRNA mycovirus of Trichoderma atroviride NFCF028.

Molecular characterization of the most common dsRNA element from Trichoderma atroviride indicated that it comprised 8,566 bp and encoded two large open reading frames (ORF1 and 2). The two ORFs were found to overlap by 46 bp with a typical (-1) slippery heptanucelotide sequence. The deduced protein sequences of ORF1 and ORF2 showed significant similarities to those of known mycoviral structural proteins and RNA-dependent RNA polymerases, respectively. Phylogenetic analysis indicated that this dsRNA is a member of a distinct species related to a group of unclassified mycoviruses; therefore, it was named Trichoderma atroviride mycovirus 1 (TaMV1).

Niveibacterium umoris gen. nov., sp. nov., isolated from wetland freshwater.

A taxonomic study was carried out on a novel bacterial strain, designated MIC2059T, which was isolated from Ungok Wetland of Gochang in Korea. Cells of the isolate were found to be Gram-stain-negative, rod-shaped and motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Rhodocyclaceae, with Uliginosibacterium gangwonense as its closest relative, with a similarity of 94.8 %. It contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) and C12 : 0 3-OH as the major fatty acids and Q8 as the respiratory ubiquinone. The polar lipid profile of strain MIC2059T revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol as major polar lipids. In addition, phosphatidylserine, an unidentified aminophospholipid and unidentified lipids were present in small amounts. The DNA G+C content of the strain was 65.1 mol%. On the basis of the evidence presented, it is concluded that strain MIC2059T represents a novel species of a novel genus within the family Rhodocyclaceae, for which the name Niveibacterium umoris gen. nov., sp. nov. is proposed. The type strain is MIC2059T ( = KACC 17062T = JCM 18716T).

Flaviaesturariibacter amylovorans gen. nov., sp. nov., a starch-hydrolysing bacterium, isolated from estuarine water.

A novel bacterial strain, designated GCR0105(T), was isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment, located in JEOLlabuk-do, South Korea. Cells of strain GCR0105(T) were Gram-stain-negative, non-motile and rod-shaped. Colonies of strain GCR0105(T) were pale yellow-pigmented on R2A agar and nutrient agar media, and were able to grow at 15-30 °C (optimum 25 °C) and pH 6.5-8.5 (optimum pH 7.5). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GCR0105(T) was related most closely to Flavisolibacter ginsengisoli Gsoil 643(T) (93.14% similarity). The polar lipid profile of strain GCR0105(T) comprised phosphatidylethanolamine, two unknown aminolipids, an unknown aminophospholipid and four unknown lipids. The DNA G+C content of strain GCR0105(T) was 42.9 mol% and the respiratory quinone was MK-7.On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain GCR0105(T) represents a novel species in a new genus within the family Chitinophagaceae, for which the name Flaviaesturariibacter amylovorans gen. nov., sp. nov. is proposed. The type strain of Flaviaesturariibacter amylovorans is GCR0105(T) ( = KACC 16454(T) = JCM 17919(T)).

Psychroflexus salarius sp. nov., isolated from Gomso salt pan.

A taxonomic study was carried out on a novel bacterial strain, designated MIC1008(T), which was isolated from the Gomso salt pan, located in Buan County, Korea. Cells were Gram-stain-negative, aerobic, non-motile and moderately halophilic rods, 0.2-0.4 µm wide and 0.7-1.2 µm long. The optimum temperature and pH for growth were 25 °C and pH 6.5-8.5, respectively. Catalase and oxidase activities were positive. Carotenoid pigments were produced. Comparison of 16S rRNA gene sequences indicated that the isolate belonged to the genus Psychroflexus, with Psychroflexus halocasei WCC 4520(T) as its closest relative, with a 16S rRNA gene sequence similarity of 95.4%. The isolate contained iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH, anteiso-C15:0 and iso-C15:0 3-OH as the major fatty acids and menaquinone MK-6 as the isoprenoid quinone. The major polar lipid profile of strain MIC1008(T) revealed the presence of phosphatidylethanolamine, an unidentified aminolipid and two unidentified lipids. The DNA G+C content of the isolate was 32.9 mol%. On the basis of the evidences presented, it is concluded that strain MIC1008(T) represents a novel species of the genus Psychroflexus within the family Flavobacteriaceae, for which the name Psychroflexus http://dx.doi.org/10.1601/nm.8182 salarius sp. nov. is proposed. The type strain is MIC1008(T) ( = KACC 17063(T) = DSM 25661(T)).

Pedobacter pituitosus sp. nov., isolated from a waterfall.

A taxonomic study was carried out on a novel bacterial strain, designated MIC2002(T), which was isolated from Wibong falls in Korea. Cells were Gram-stain-negative, aerobic, non-motile and rods, 0.3-0.5 µm wide and 4.0-5.0 µm long. The optimum temperature and pH range for growth were 25 °C and pH 6.5-7.0, respectively. Catalase and oxidase activities were positive. Flexirubin pigments were not produced. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the genus Pedobacter, with Pedobacter daechungensis as its closest relative, with a similarity of 94.4%. It contained iso-C(15:0), anteiso-C(15:0), C(16:0), summed feature 3 (C(16:1)ω6c and/or C(16:1)ω7c) and iso-C(17:0) 3-OH as the major fatty acids and menaquinone MK-7 as isoprenoid quinone. The polar lipid profile of strain MIC2002(T) revealed the presence of phosphatidylethanolamine and an unknown lipid. The DNA G+C content of the strain was 34.7 mol%. On the basis of the evidences presented, it was concluded that strain MIC2002(T) represents a novel species of the genus Pedobacter within the family Sphingobacteriaceae, for which the name Pedobacter pituitosus sp. nov. is proposed. The type strain is MIC2002(T) ( =KACC 17064(T) =JCM 18729(T)).

Metabolic engineering of Saccharomyces cerevisiae for the biosynthesis of a fungal pigment from the phytopathogenic fungus Cladosporium phlei.

BACKGROUND: Cladosporium phlei is a phytopathogenic fungus that produces a pigment called phleichrome. This fungal perylenequinone plays an important role in the production of a photosensitizer that is a necessary component of photodynamic therapy. We applied synthetic biology to produce phleichrome using Saccharomyces cerevisiae. RESULTS: The gene Cppks1, which encodes a non-reducing polyketide synthase (NR-PKS) responsible for the biosynthesis of phleichrome in C. phlei, was cloned into a yeast episomal vector and used to transform S. cerevisiae. In addition, a gene encoding a phosphopantetheinyl transferase (PPTase) of Aspergillus nidulans was cloned into a yeast integrative vector and also introduced into S. cerevisiae for the enzymatic activation of the protein product of Cppks1. Co-transformed yeasts were screened on a leucine/uracil-deficient selective medium and the presence of both integrative as well as episomal recombinant plasmids in the yeast were confirmed by colony PCR. The episomal vector for Cppks1 expression was so dramatically unstable during cultivation that most cells lost their episomal vector rapidly in nonselective media. This loss was also observed to a less degree in selective media. This data strongly suggests that the presence of the Cppks1 gene exerts a significant detrimental effect on the growth of transformed yeast cells and that selection pressure is required to maintain the Cppks1-expressing vector. The co-transformants on the selective medium showed the distinctive changes in pigmentation after a period of prolonged cultivation at 20 °C and 25 °C, but not at 30 °C. Furthermore, thin layer chromatography (TLC) revealed the presence of a spot corresponding with the purified phleichrome in the extract from the cells of the co-transformants. Liquid chromatography (LC/MS/MS) verified that the newly expressed pigment was indeed phleichrome. CONCLUSION: Our results indicate that metabolic engineering by multiple gene expression is possible and capable of producing fungal pigment phleichrome in S. cerevisiae. This result adds to our understanding of the characteristics of fungal PKS genes, which exhibit complex structures and diverse biological activities.

The MpkB MAP kinase plays a role in autolysis and conidiation of Aspergillus nidulans.

The mpkB gene of Aspergillus nidulans encodes a MAP kinase homologous to Fus3p of Saccharomyces cerevisiae which is involved in conjugation process. MpkB is required for completing the sexual development at the anastomosis and post-karyogamy stages. The mpkB deletion strain could produce conidia under the repression condition of conidiation such as sealing and even in the submerged culture concomitant with persistent brlA expression, implying that MpkB might have a role in timely regulation of brlA expression. The submerged culture of the deletion strain showed typical autolytic phenotypes including decrease in dry cell mass (DCM), disorganization of mycelial balls, and fragmentation of hyphae. The chiB, engA and pepJ genes which are encoding cell wall hydrolytic enzymes were transcribed highly in the submerged culture. Also, we observed that the enzyme activity of chitinase and glucanase in the submerged culture of mpkB deletion strain was much higher than that of wild type. The deletion of mpkB also caused a precocious germination of conidia and reduction of spore viability. The expression of the vosA gene, a member of velvet gene family, was not observed in the mpkB deletion strain. These results suggest that MpkB should have multiple roles in germination and viability of conidia, conidiation and autolysis through regulating the expression of vosA and brlA.

Flavobacterium fontis sp. nov., isolated from freshwater.

A taxonomic study was carried out on a novel bacterial strain, designated MIC3010(T), which was isolated from a freshwater pond in Jeonju, Republic of Korea. Cells of the isolate were Gram-stain-negative, rod-shaped and non-motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Flavobacteriaceae, with Flavobacterium haoranii LQY-7(T) as its closest relative, with a similarity of 94.2 %. The predominant fatty acids of strain MIC3010(T) were iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile of strain MIC3010(T) revealed the presence of phosphatidylethanolamine (PE) and one unidentified lipid (L1) as major components. In addition, two aminolipids (AL1, AL2) and one glycolipid were present in small amounts. The DNA G+C content of the strain was 41.0 mol%. The strain contained MK-6 as the major quinone and sym-homospermidine as the predominant polyamine. On the basis of the evidence presented, it is concluded that strain MIC3010(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium fontis sp. nov. is proposed. The type strain is MIC3010(T) ( = KACC 16593(T) = JCM 18212(T)).

Flavobacterium aciduliphilum sp. nov., isolated from freshwater, and emended description of the genus Flavobacterium.

A Gram-stain-negative, rod-shaped, non-motile and yellow-pigmented bacterial strain, designated strain JJ013(T), was isolated from an artificial lake in Jeollabuk-do, South Korea, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ013(T) indicated that the isolate belonged to the family Flavobacteriaceae and exhibited similarity levels of 96.6 % to the type strains of Flavobacterium cheonanense and Flavobacterium koreense and 96.5 % to the type strain of Flavobacterium chungnamense. Growth was observed at 20-30 °C and pH 5.0-7.0. The major cellular fatty acids of the novel strain were iso-C15 : 0 (27.5 %), iso-C15 : 1 G (17.8 %), iso-C17 : 0 3-OH (9.4 %) and iso-C15 : 0 3-OH (9.2 %). Flexirubin-type pigments were present. The DNA G+C content of strain JJ013(T) was 33.9 mol%, the major respiratory quinone was menaquinone-6 (MK-6) and the major polyamine was sym-homospermidine. The polar lipid profile of the strain JJ013(T) consisted of a phosphatidylethanolamine (PE), two unknown aminolipids (AL1-2), three unidentified lipid (L1-3) and an unknown glycolipid (GL). On the basis of the morphological and physiological properties and biochemical evidence presented, it is concluded that strain JJ013(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium aciduliphilum sp. nov. is proposed; the type strain is JJ013(T) ( = KACC 16594(T) = JCM 18211(T)). Since C15 : 0, which is known as a predominant fatty acid of the genus Flavobacterium was not detected in the novel strain and other reference strains, we propose an emended description of the genus Flavobacterium.

Nibribacter koreensis gen. nov., sp. nov., isolated from estuarine water.

A Gram-reaction-negative, rod-shaped, non-motile, red-pigmented bacterium, designated strain GSR3061(T), was isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment in JEOLlabuk-do of South Korea, and characterized using a polyphasic approach. 16S rRNA gene sequence analysis of strain GSR3061(T) indicated that the isolate belonged to the phylum Bacteroidetes and exhibited similarity levels of 94.7 % to Rufibacter tibetensis NRRL B-51285(T), 92.4 % to Adhaeribacter terreus KACC 14257(T) and 91.9 % to Pontibacter korlensis KACC 15371(T). Growth was observed at 15-40 °C and pH 6.5-9.5. The major cellular fatty acids of the novel strain were summed feature 4 (comprising iso-C17 : 1 I and/or anteiso-C17 : 1 B), iso-C15 : 0, C17 : 1ω6c and iso-C16 : 1 H. Flexirubin-type pigments were absent. The DNA G+C content of strain GSR3061(T) was 44.9 mol% and the major quinone was MK-7. The polar lipid profile consisted mainly of phosphatidylethanolamine; three unidentified lipids, two unknown aminolipids, two unknown phospholipids, an unknown aminophospholipid and an unknown glycolipid were also present. On the basis of the evidence presented, it is concluded that strain GSR3061(T) represents a novel species of a new genus, for which the name Nibribacter koreensis gen. nov., sp. nov. is proposed. The type strain of Nibribacter koreensis is GSR3061(T) ( = KACC 16450(T) = JCM 17917(T)).

Dyadobacter jejuensis sp. nov., isolated from seawater.

A taxonomic study was carried out on a novel bacterial strain, designated AM1R11(T), which was isolated from seawater of Jeju Island in Korea. Cells of the isolate were found to be Gram-negative, rod-shaped and non-motile. Comparison of the 16S rRNA gene sequences indicated that the isolate belonged to the family Cytophagaceae, with Dyadobacter ginsengisoli Gsoil 043(T) as its closest relative, with a similarity of 96.6 %. It contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 36.9 %), iso-C15 : 0 (16.5 %) and C16 : 1ω5c (16.3 %) as the major fatty acids and MK-7 as the predominant menaquinone. The polar lipid profile of strain AM1R11(T) revealed the presence of phosphatidylethanolamine, one aminolipid and four unidentified lipids (L1, L2, L3 and L4). The DNA G+C content of strain AM1R11(T) was 45.1 mol%. On the basis of the evidence presented, it is concluded that strain AM1R11(T) represents a novel species of the genus Dyadobacter, for which the name Dyadobacter jejuensis sp. nov. is proposed. The type strain is AM1R11(T) ( = KACC 16446(T) = JCM 17918(T)).

Pontibacter saemangeumensis sp. nov., isolated from seawater.

A gram-negative, rod-shaped, non-motile and pink bacterial strain, designated strain GCM0142(T), was isolated from the confined seawater in the Saemangeum Tide Embankment of South Korea, and characterized using a polyphasic approach. 16S rRNA gene sequence analysis of strain GCM0142(T) indicated that the isolate belonged to the phylum Bacteroidetes and exhibited similarity levels of 94.0-96.4 % to the type strains of recognized Pontibacter species. Strain GCM0142(T) was oxidase- and catalase-positive. The major cellular fatty acids of the novel strain were summed feature 4 (comprising iso-C(17 : 1)I and/or anteiso-C(17 : 1)B, 36.8 %), iso-C(15 : 0) (22.3 %) and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c, 6.2 %). The DNA G+C content of strain GCM0142(T) was 48.9 mol% and the major quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, two unknown aminolipids (AL1-2), an unknown aminophospholipid, five unknown lipids (L1-5) and an unknown glycolipid. On the basis of the evidence presented, strain GCM0142(T) is considered to represent a novel species of the genus Pontibacter, for which the name Pontibacter saemangeumensis sp. nov. is proposed. The type strain is GCM0142(T) ( = KACC 16448(T) = JCM 17926(T)).

Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov., novel members of the family Cytophagaceae, isolated from seawater.

Two strains, designated GCR0103(T) and GYR3121(T), were isolated from seawater of the Saemangeum Embankment in Jeollabuk-do, Korea. The cells of the two strains were Gram-reaction-negative and non-motile, and formed multicellular filaments. The colonies of the two strains were pink-pigmented and able to grow at 15-37 °C (optimum 25 °C) on R2A and NA medium. Strains GCR0103(T) and GYR3121(T) grew at pH 6.5-10 (optimum pH 7.5) and pH 5.5-9.5 (optimum pH 7.5), and within NaCl ranges of 0-0.4% and 0-1%, respectively. The polar lipid profiles of the two strains contained phosphatidylethanolamine, five unknown aminolipids, an unknown phospholipid and four or five unknown lipids. The DNA G+C contents of strains GCR0103(T) and GYR3121(T) were 56.0 and 54.5 mol%, respectively. The respiratory quinone detected in both strains was MK-7. The 16S rRNA gene sequence similarity between GCR0103(T) and GYR3121(T) was 95.5 %. The 16S rRNA gene sequence similarities of the two strains to closely related reference strains were less than 89 %. Phylogenetic analysis based on 16S rRNA genes showed that GCR0103(T) and GYR3121(T) formed a distinct phyletic line in the family Cytophagaceae. On the basis of the phenotypic, chemotaxonomic and phylogenetic properties, strains GCR0103(T) and GYR3121(T) represent two novel species in a new genus within the family Cytophagaceae, for which the names Nibrella saemangeumensis gen. nov., sp. nov. and Nibrella viscosa sp. nov. are proposed. The type strain of Nibrella saemangeumensis is GCR0103(T) ( = KACC 16453(T) = JCM 17927(T)) and the type strain of Nibrella viscosa is GYR3121(T) ( = KACC 16447(T) = JCM 17925(T)).