Optimization of bacterioruberin production from Halorubrum ruber and assessment of its antioxidant potential.

Haloarchaea produce bacterioruberin, a major C50 carotenoid with antioxidant properties that allow for its potential application in the food, cosmetic, and pharmaceutical industries. This study aimed to optimize culture conditions for total carotenoid, predominantly comprising bacterioruberin, production using Halorubrum ruber MBLA0099. A one-factor-at-a-time and statistically-based experimental design were applied to optimize the culture conditions. Culture in the optimized medium caused an increase in total carotenoid production from 0.496 to 1.966 mg L- 1 Maximal carotenoid productivity was achieved in a 7-L laboratory-scale fermentation and represented a 6.05-fold increase (0.492 mg L-1 d-1). The carotenoid extracts from strain MBLA0099 exhibited a 1.8-10.3-fold higher antioxidant activity in vitro, and allowed for a higher survival rate of Caenorhabditis elegans under oxidative stress conditions. These results demonstrated that Hrr. ruber MBLA0099 has significant potential as a haloarchaon for the commercial production of bacterioruberin.

Paenibacillus mellifer sp. nov., isolated from gut of the honey bee Apis mellifera.

An isolate, designated MBLB2552T, was isolated from the gut of the honey bees (Apis mellifera L.) and identified as a member of the genus Paenibacillus based on the sequences of the 16S rRNA gene sequences. The most closely related species to strain MBLB2552T were Paenibacillus timonensis 2301032 T, Paenibacillus barengoltzii NBRC 101215 T, and Paenibacillus macerans IAM 12467 T, with similarity values of 98.1, 97.21 and 97.0%, respectively, based on 16S rRNA gene sequences. The genome size and G + C content of MBLB2552T were 5.2 Mb and 52.4%, respectively. The Ortho average nucleotide identity (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between strain MBLB2552T and the type strains of the closest species were below the species delineation threshold. Comparative genomic analysis showed that most core POGs of strain MBLB2552T and other related taxa were related to translation, ribosomal structure and biogenesis (J) and carbohydrate metabolism in the COG category and KEGG pathways, respectively. Strain MBLB2552T was Gram stain-positive, spore-forming, rod-shaped, facultative anaerobic, motile, and grew at 20‒45 °C in 0‒2% (w/v) NaCl at pH 6.0‒9.0. The major polar lipids identified were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylserine, unidentified polar lipids, and an unidentified glycolipid. We propose that strain MBLB2552T represents the type strain of the genus Paenibacillus and its name Paenibacillus mellifer sp. nov. is proposed. The type of strain was MBLB2552T (= JCM 35371 T = KCTC 43386 T).

Fictibacillus marinisediminis sp. nov., a nitrate-reducing bacterium isolated from marine sediment in Hupo Basin, Republic of Korea.

An isolate, designated strain KIGAM418T was isolated from marine mud below 192 m depth in the Hupo Basin, Republic of Korea. Strain KIGAM418T was Gram-stain positive, spore-forming, rod-shaped, facultatively anaerobic, and grew at 10‒45 °C, in 0‒2% (w/v) NaCl at pH 4.0‒12.0. The strain tested positive for catalase, oxidase, and motility. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain KIGAM418T was related to the genus Fictibacillus. The strain showed the highest similarity to Fictibacillus rigui WPCB074T (98.0-98.1%) and Fictibacillus solisalsi YC1T (97.2-97.8%). The diagnostic diamino acid of the cell wall was meso-diaminopimelic acid. The major fatty acids were characterized as anteiso-C15:0 and iso-C15:0. Strain KIGAM418T possessed diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine as the major polar lipids and menaquinone-7 as the predominant menaquinone. The genome size and G + C content were 4.56 Mb and 43.2 mol%, respectively. According to predicted functional genes of the genome, the category of amino acid transport and metabolism was mainly distributed. Based on the polyphasic taxonomic data, strain KIGAM418T represents a novel species of the genus Fictibacillus, for which the name Fictibacillus marinisediminis sp. nov. is proposed. The type strain is KIGAM418T (= KCTC 43291 T = JCM 34437 T).

Genome analysis of 1-deoxynojirimycin (1-DNJ)-producing Bacillus velezensis K26 and distribution of Bacillus sp. harboring a 1-DNJ biosynthetic gene cluster.

1-Deoxynojirumycin (1-DNJ) is a representative iminosugar with α-glucosidase inhibition (AGI) activity. In this study, the full genome sequencing of 1-DNJ-producing Bacillus velezensis K26 was performed. The genome consists of a circular chromosome (4,047,350 bps) with two types of putative virulence factors, five antibiotic resistance genes, and seven secondary metabolite biosynthetic gene clusters. Genomic analysis of a wide range of Bacillus species revealed that a 1-DNJ biosynthetic gene cluster was commonly present in four Bacillus species (B. velezensis, B. pseudomycoides, B. amyloliquefaciens, and B. atrophaeus). In vitro experiments revealed that the increased mRNA expression levels of the three 1-DNJ biosynthetic genes were closely related to increased AGI activity. Genomic comparison and alignment of multiple gene sequences indicated the conservation of the 1-DNJ biosynthetic gene cluster in each Bacillus species. This genomic analysis of Bacillus species having a 1-DNJ biosynthetic gene cluster could provide a basis for further research on 1-DNJ-producing bacteria.

Expression, purification, and characterization of glutamate decarboxylase from human gut-originated Lactococcus garvieae MJF010.

Human gut-originated lactic acid bacteria were cultivated, and high γ-aminobutyric acid (GABA)-producing Lactococcus garvieae MJF010 was identified. To date, despite the importance of GABA, no studies have investigated GABA-producing Lactococcus species, except for Lc. lactis. A recombinant glutamate decarboxylase of the strain MJF010 (rLgGad) was successfully expressed in Escherichia coli BL21(DE3) with a size of 53.9 kDa. rLgGad could produce GABA, which was verified using the silylation-derivative fragment ions of GABA. The purified rLgGad showed the highest GABA-producing activity at 35 °C and pH 5. rLgGad showed a melting temperature of 43.84 °C. At 30 °C, more than 80% of the activity was maintained even after 7 h; however, it rapidly decreased at 50 °C. The kinetic parameters, Km, Vmax, and kcat, of rLgGad were 2.94 mM, 0.023 mM/min, and 12.3 min- 1, respectively. The metal reagents of CaCl2, MgCl2, and ZnCl2 significantly had positive effects on rLgGad activity. However, most coenzymes including pyridoxal 5'-phosphate showed no significant effects on enzyme activity. In conclusion, this is the first report of Gad from Lc. garvieae species and provides important enzymatic information related to GABA biosynthesis in the Lactococcus genus.

Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., low salt-tolerant haloarchaea isolated from seawater and sediment.

Three novel halophilic archaea were isolated from seawater and sediment near Yeoungheungdo Island, Republic of Korea. The genome size and G + C content of the isolates MBLA0076T, MBLA0077T, and MBLA0078T were 3.56, 3.48, and 3.48 Mb and 61.7, 60.8, and 61.1 mol%, respectively. The three strains shared 98.5-99.5 % sequence similarity of the 16 S rRNA gene, whereas their sequence similarity to the 16 S rRNA gene of type strains was below 98.5 %. Phylogenetic analysis based on sequences of the 16 S rRNA and RNA polymerase subunit beta genes indicated that the isolates belonged to the genus Haloferax. The orthologous average nucleotide identity, average amino-acid identity, and in silico DNA-DNA hybridization values were below species delineation thresholds. Pan-genomic analysis indicated that the three novel strains and 11 reference strains had 8981 pan-orthologous groups in total. Fourteen Haloferax strains shared 1766 core pan-genome orthologous groups, which were mainly related to amino acid transport and metabolism. Cells of the three isolates were gram-negative, motile, red-pink pigmented, and pleomorphic. The strains grew optimally at 30 °C (MBLA0076T) and 40 °C (MBLA0077T, MBLA0078T) in the presence of 1.28 M (MBLA0077T) and 1.7 M (MBLA0076T, MBLA0078T) NaCl and 0.1 M (MBLA0077T), 0.2 M (MBLA0076T), and 0.3 M (MBLA0078T) MgCl2·6H2O at pH 7.0-8.0. Cells of all isolates lysed in distilled water; the minimum NaCl concentration necessary to prevent lysis was 0.43 M. The major polar lipids of the three strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and sulphated diglycosyl archaeol-1. Based on their phenotypic and genotypic properties, MBLA0076T, MBLA0077T, and MBLA0078T were described as novel species of Haloferax, for which we propose the names Haloferax litoreum sp. nov., Haloferax marinisediminis sp. nov., and Haloferax marinum sp. nov., respectively. The respective type strains of these species are MBLA0076T (= KCTC 4288T = JCM 34,169T), MBLA0077T (= KCTC 4289T = JCM 34,170T), and MBLA0078T (= KCTC 4290T = JCM 34,171T).

Halobellus ruber sp. nov., a deep red-pigmented extremely halophilic archaeon isolated from a Korean solar saltern.

A novel halophilic archaeon, strain MBLA0160T, was isolated from a solar saltern in Sorae, Republic of Korea. The cells are deep-red pigmented, Gram-negative, rod shaped, motile, and lysed in distilled water. The strain MBLA0160T grew at 25-45 °C (optimum 37 °C), in 15-30% (w/v) NaCl (optimum 20%) and 0.1-1.0 M MgCl2 (optimum 0.3-0.5 M) at pH 5.0-9.0 (optimum 7.0). Phylogenetic analysis based on the 16S rRNA sequence showed that this strain was related to two species within the genus Halobellus (Hbs.), with 98.4% and 95.8% similarity to Hbs. salinus CSW2.24.4 T and Hbs. clavatus TNN18T, respectively. The major polar lipids of the strain MBLA160T were phosphatidylglycerol, phosphatidylglycerol sulfate, and phosphatidylglycerol phosphate methyl ester. The genome size, G + C content, and N50 value of MBLA0160T were 3.49 Mb, 66.5 mol%, and 620,127 bp, respectively. According to predicted functional proteins of strain MBLA0160T, the highest category was amino acid transport and metabolism. Genome rapid annotation showed that amino acid and derivatives was the most subsystem feature counts. Pan-genomic analysis showed that strain MBLA0160T had 97 annotated unique KEGG, which were mainly included metabolism and environmental information processing. Ortholog average nucleotide identities (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between the strain MBLA0160T and other strains of the genus Halobellus were under 84,4% and 28.1%, respectively. The genome of strain MBLA0160T also contain the biosynthetic gene cluster for C50 carotenoid as secondary metabolite. Based on the phylogenetic, phenotypic, chemotaxonomic properties, and comparative genomic analyses, strain MBLA0160T is considered to represent a novel species of the genus Halobellus, for which the name Halobellus ruber sp. nov. is proposed. The type strain is MBLA0160T (= KCTC 4291 T = JCM 34172 T).

Nocardioides luti sp. nov., belonging to the family Nocardioidaceae isolated from kaolinite, exhibiting the biosynthesis potential of alkylresorcinol.

A novel Gram-staining-positive, short rod-shaped, non-motile, and non-pigmented actinobacterial strain (KIGAM211T) was isolated from kaolinite, a soft white clay mineral, collected from Sancheong in the Republic of Korea. On the basis of 16S rRNA gene sequence analysis, strain KIGAM211T was determined to belong to the genus Nocardioides and was most closely related to N. ungokensis UKS-03T (97.5% similarity). Cells could grow between 4 and 35 °C (optimum 30 °C), 0-3% (w/v) NaCl concentration (optimum 0%) and pH 5.5-8.5 (optimum 7.0) on R2A agar. Morphological appearance of colonies was cream-white, arranged singly or in groups. Biochemical characterization of strain KAGAM211T indicated that it could hydrolyze casein, gelatin, Tweens 40 and tyrosine. Furthermore, the strain was positive for both oxidase and catalase activity. Strain KIGAM211T was characterized chemotaxonomically by MK-8 (H4) as the predominant menaquinone and phosphatidylglycerol (PG) and phosphatidylinositol (PI) as the major polar lipids. Major fatty acids were iso-C16:0 and C18:1 ω9c. The Ortholog average nucleotide identity (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between strain KIGAM211T and its most closely related strains of the Nocardioides genus were < 82% and < 24%, respectively, suggesting that strain KIGAM211T represent a novel species. The whole genome size of KIGAM211T was 4.52 Mb, comprising a total of 4,294 genes with DNA G + C content of 72.3 mol%. The genome of strain KIGAM211T also comprises the biosynthetic gene cluster for alkylresorcinol as secondary metabolite. The results of physiological, taxonomical, phylogenetic, and whole genome analyses allowed for differentiation of strain KIGAM211T from the recognized Nocardioides species. Therefore, strain KIGAM211T is considered to represent a novel species, for which the name Nocardioides luti sp. nov. (type strain KIGAM211T = KCTC 49364T = JCM 33859T) is proposed.

Characterization of a potential probiotic bacterium Lactococcus raffinolactis WiKim0068 isolated from fermented vegetable using genomic and in vitro analyses.

BACKGROUND: Lactococcus members belonging to lactic acid bacteria are widely used as starter bacteria in the production of fermented dairy products. From kimchi, a Korean food made of fermented vegetables, Lactococcus raffinolactis WiKim0068 was isolated and its genome was analyzed. RESULTS: The complete genome of the strain WiKim0068 consists of one chromosome and two plasmids that comprises 2,292,235 bp, with a G + C content of 39.7 mol%. Analysis of orthoANI values among Lactococcus genome sequences showed that the strain WiKim0068 has > 67% sequence similarity to other species and subspecies. In addition, it displayed no antibiotic resistance and can metabolize nicotinate and nicotinamide (vitamin B3). CONCLUSION: These results augments our understanding of the genus Lactococcus and suggest that this new strain has potential industrial applications.

Hymenobacter lutimineralis sp. nov., belonging to the family Hymenobacteraceae, isolated from zeolite.

A red-pigmented bacterial strain, designated KIGAM108T, within the family Hymenobacteraceae was isolated from zeolite in the Gampo-41 mine of the Gyeongju, Republic of Korea. This strain was a Gram-negative, strictly aerobic, non-spore forming, rod-shaped bacterium. Phylogenetic analysis of the 16S rRNA gene sequence of strain KIGAM108T found that it was related to the genus Hymenobacter, with similarities of 96.6, 96.4, 95.5, and 95.0% to H. fastidiosus VUG-A124T, H. algoricola VUG-A23aT, H. crusticola MIMBbqt21T, and H. daecheongensis DSM 21074T, respectively. Strain KIGAM108T grew in the presence of 0-0.5% (w/v) NaCl at 4-37 °C and pH 6.0-10.0. This isolate contained MK-7 as a respiratory quinone. The polar lipids of strain KIGAM108T were identified as phosphatidylethanolamine, two unidentified aminophospholipids, one unidentified phospholipid and five unidentified lipids. The major fatty acids profile showed summed feature 3 (C16:1ω6c and/or C16:1ω7c) (22.3%), anteiso-C15:0 (17.1%), C16:1ω5c (13.3%), and iso-C15:0 (11.0%). The genomic DNA G + C content was 60.0 mol%. Based on the polyphasic taxonomic data, strain KIGAM108T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter lutimineralis sp. nov. is proposed. The type strain is KIGAM108T (=KCTC 72263T =JCM 33444T).

Roseovarius faecimaris sp. nov., isolated from a tidal flat.

A Gram-stain-negative, obligate aerobic, non-motile and rod-shaped bacterium, designated MME-070T, was isolated from a tidal flat near Muui-do, Incheon, Republic of Korea. This bacterium belonged to the Roseobacterclade within the family Rhodobacteraceae. The isolate grew at 20-40 °C, pH 7.0-9.0 with 1-5 % (w/v) NaCl. Optimal growth required 2-3 % (w/v) NaCl at 25-30 °C and pH 8.0. The 16S rRNA gene sequence of strain MME-070T was most closely related to Roseovarius aestuarii SMK-122T (96.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain MME-070T clustered with the genus Roseovarius. The sole respiratory quinone was Q-10. Polar lipids were phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, unidentified aminolipid and some unidentified lipids. Major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), 11-methyl C18 : 1ω7c and C16 : 0. The genomic DNA G+C content of the type strain was 63.6 mol%. Based on polyphasic taxonomic analysis, strain MME-070T is proposed to represent a novel species of the genus Roseovarius, for which the name Roseovarius faecimaris sp. nov. is proposed. The type strain is MME-070T (=KCCM 43142T=JCM 30757T).

Paenibacillus lutimineralis sp. nov., Isolated From Bentonite.

Strain MBLB1234T was isolated from bentonite samples collected at Guryong mining area located in Pohang, Republic of Korea and was taxonomically characterized by a polyphasic approach. This strain was a Gram-stain-negative, motile, endospore-forming, facultative anaerobic, catalase-positive, oxidase-negative, and rod-shaped bacterium. Strain MBLB1234T was able to grow at 20‒45 °C (optimum, 37 °C), pH 6.0‒10.0 (optimum, 7.0-8.0), and 0‒5.0% (w/v) NaCl (optimum, 0.5%). Genome size was 6,497,679 bp with a G + C content of 46.4 mol %. The genome was predicted to contain 5233 protein-coding genes, and 135 rRNA genes consisted of 10 5S rRNAs, 10 16S rRNAs, 10 23S rRNAs, and 105 tRNAs. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain MBLB1234T clustered with Paenibacillus motobuensis JCM 12774T and P. aceti JCM 31170T with 98.3-98.5% and 97.2-97.4% sequencing similarity, respectively. The major fatty acids of strain MBLB1234T were anteiso-C15:0 (35.7%), anteiso-C17:0 (17.8%), iso-C17:0 (14.5%), and C16:0 (11.0%). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, and one unidentified phospholipid, six unidentified aminophospholipids, and one unidentified lipid. The predominant isoprenoid quinone was menaquinone-7. DNA-DNA hybridization values between strain MBLB1234T and P. motobuensis JCM 12774T and P. aceti JCM 31170T were 34 and 38%, respectively. Average nucleotide identity value between strains MBLB1234T and P. aceti L14T was 82.3%. Based on characteristics of genomic, phenotypic, chemotaxonomic, and phylogenetic analyses, strain MBLB1234T represents a novel species of the genus P. , for which the name P. lutimineralis sp. nov. is proposed. The type strain is MBLB1234T (= JCM 32684T = KCTC 33978T).

Haloplanus rallus sp. nov., a halophilic archaeon isolated from crude solar salt.

A halophilic archaeon, strain MBLA0036T, was isolated from Sorae solar saltern near Incheon, Republic of Korea. Strain MBLA0036T had three 16S rRNA genes: rrnA, rrnB and rrnC. The 16S rRNA gene sequence similarities between strain MBLA0036T (based on the rrnA gene) and Haloplanus ruber R35T and Haloplanus litoreus GX21T were 98.0 and 97.3 %, respectively. The similarities of the RNA polymerase subunit B' gene between strain MBLA0036T and H. ruber R35T and H. litoreus GX21T were 94.0 and 92.1 %, respectively. Cells of strain MBLA0036T were Gram-stain-negative, motile, red-pigmented, pleomorphic, flat and contained gas vesicles. Strain MBLA0036T grew at 15‒55 °C (optimum, 37 °C), in 10‒30 % (w/v) NaCl (15 %, w/v) with 0‒0.5 M MgSO4.7H2O (0.2 M) and at pH 6.0-9.0 (pH 7.0). The cells lysed in distilled water and the minimum NaCl concentration that prevented cell lysis was 5 % (w/v). Major polar lipids of strain MBLA0036T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a glycolipid that was chromatographically identical to sulfated mannosyl glucosyl diether. The major isoprenoid quinone was menaquinone-8. The genomic DNA G+C content was 65.5 mol%. DNA-DNA hybridization values between strain MBLA0036T and H. ruber JCM 17271T and H. litoreus JCM 17092T were 35±3 and 18±1 %, respectively. Therefore, strain MBLA0036T is described a novel species of the Haloplanus, for which we propose the name Haloplanusrallus sp. nov. The type strain is MBLA0036T (=KCTC 4239T=JCM 31425T).

Expression and characterization of glutamate decarboxylase from Lactobacillus brevis HYE1 isolated from kimchi.

A putative gene (gadlbhye1) encoding glutamate decarboxylase (GAD) was cloned from Lactobacillus brevis HYE1 isolated from kimchi, a traditional Korean fermented vegetable. The amino acid sequences of GADLbHYE1 showed 48% homology with the GadA family and 99% identity with the GadB family from L. brevis. The cloned GADLbHYE1 was functionally expressed in Escherichia coli using inducible expression vectors. The expressed recombinant GADLbHYE1 was successfully purified by Ni-NTA affinity chromatography, and had a molecular mass of 54 kDa with optimal hydrolysis activity at 55 °C and pH 4.0. Its thermal stability was determined to be higher than that of other GADs from L. brevis, based on its melting temperature (75.18 °C). Kinetic parameters including Km and Vmax values for GADLbHYE1 were 4.99 mmol/L and 0.224 mmol/L/min, respectively. In addition, the production of gamma-aminobutyric acid in E. coli BL21 harboring gadlbhye1/pET28a was increased by adding pyridoxine as a cheaper coenzyme.

Nioella aestuarii sp. nov., of the family Rhodobacteraceae, isolated from tidal flat.

A bacterium, designated strain MME-018T, was isolated from a tidal flat of the Muui-do in the Republic of Korea and identified within the family Rhodobacteraceae. The 16S rRNA gene sequence of the isolate showed the highest similarity to that of Nioella sediminis JS7-11T (98.9 %), followed by Nioella nitratireducens SSW136T (97.1 %). In phylogenetic analyses, these taxa formed a clade at neighbour-joining, maximum-likelihood, and maximum-parsimony algorithms, in which it was separated from other genus belonging to the family Rhodobacteraceae. Ubiquinone-10 (Q-10) was the major respiratory quinone. Major polar lipids included phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two unidentified phospholipids, and an unidentified lipid. Major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) C16 : 0, cyclo C19 : 0ω8c, and 11-methyl C18 : 1ω7c. Genomic DNA G+C content was 61 mol%. Cells were Gram-stain negative, non-motile, aerobic, and rod-shaped. This strain grew in 1‒4 % (w/v) NaCl, at 4-40 °C and pH 6.0‒8.0, with optimal growth in 2 % (w/v) NaCl, at 25‒30 °C and pH 7.0. DNA-DNA hybridization values between strain MME-018T and Nioella sediminis KCTC 42144T and Nioella nitratireducens KCTC 32417T were 17±3 and 13±1 %, respectively. On the basis of polyphasic taxonomic analysis, strain MME-018T is proposed to represent a novel species of the genus Nioella, for which the name Nioellaaestuarii sp. nov. The type strain of Nioellaaestuarii is MME-018T (=KCCM 43135T=JCM 30752T).

Paenibacillus arcticus sp. nov., isolated from Arctic soil.

A Gram-positive, endospore-forming, strictly aerobic and rod-shaped bacterium, designated strain MME2_R6T, was isolated from Arctic soil, and it was identified by using a polyphasic taxonomic approach. This strain was psychrotolerant, growing at 4‒24 °C. 16S rRNA gene sequence analysis showed that strain MME2_R6T was closest to Paenibacillus swuensis DY6T, with 93.9 % similarity. However, in phylogenetic analysis based on the 16S rRNA gene sequence, strain MME2_R6T showed that it clustered with Paenibacillus contaminans CKOBP-6T and the sequencing similarity between the two species was 93.7 %. Its major cellular fatty acid was anteiso-C15 : 0, like other Paenibacillus species. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The predominant isoprenoid quinone was menaquinone-7. The diagnostic diamino acid in the cell wall was meso-diaminopimelic acid. The genomic DNA G+C content was 44.2 mol%. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, a novel species, Paenibacillus arcticus sp. nov., is proposed. The type strain is MME2_R6T (=JCM 30981T=PAMC 28731T).

Flavimarina flava sp. nov., isolated from Salicornia herbacea.

A Gram-stain-negative, motile-by-gliding, aerobic, non-spore-forming, rod-shaped and yellow-pigmented bacterium was isolated from Salicornia herbacea in the Yellow Sea and designated as strain MBLN091T. It belonged to the family Flavobacteriaceae. The 16S rRNA gene sequence of this isolated strain was similar to that of Flavimarina pacifica IDSW-73T with 94.8 % similarity, and with 92.3-92.8 % similarities to those of other closely related species of the genus Leeuwenhoekiella. The similarities of the RNA polymerase subunit B gene between this strain and F. pacifica KCTC 32466T and Leeuwenhoekiella marinoflava DSM 3653T were 80.5 and 80.2 %, respectively. Growth of strain MBLN091T was observed in the presence of 0.5‒15.0 % (w/v) NaCl at 4‒35 °C and pH 6.0-8.0, with optimal growth in the presence of 2.5‒5.0 % (w/v) NaCl at 20‒25 °C and pH 7.0. This isolate was able to hydrolyse gelatin. The only respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and two unidentified lipids. Major fatty acids of the isolate were iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), iso-C17 : 0 3-OH and iso-C15 : 1 G. The genomic DNA G+C content was 39.6 mol%. The physiological features were closely related to F. pacifica. Therefore, strain MBLN091T is considered to represent a novel species within the genus Flavimarina, for which the name Flavimarina flava sp. nov. is proposed. The type strain is MBLN091T (=KCTC 52527T=JCM 31731T).

Lawsonia intracellularis in the feces of wild rodents and stray cats captured around equine farms.

BACKGROUND: Proliferative enteropathy is a global enteric disease of particular importance in pigs. The causative bacterium, Lawsonia intracellularis, has a wide range of susceptible host species. Recently, L. intracellularis has been recognized as an etiologic agent of an emerging enteric disease in foals called equine proliferative enteropathy (EPE). The presence of L. intracellularis in nonruminant wildlife has raised questions regarding the role of these species in EPE transmission. RESULTS: This study investigated exposure to L. intracellularis in wild rodents and feral cats from eight farms with confirmed EPE. Serum (42) and fecal (40) samples from resident foals and fecal samples (131), intestinal mucosa tissues (14), and mesenteric lymph nodes (14) from wild and feral animals were collected for the evaluation of the farm status and the molecular detection of L. intracellularis following the diagnosis of EPE in index cases. Fresh feces from wild rodents and feral cats were collected from the ground while walking the premises or after trapping the animals using live traps. A total of 3 brown rats, 7 house mice, 1 striped field mouse, 2 grey red-backed voles, and 3 feral cats showed evidence of prior exposure to L. intracellularis. CONCLUSIONS: Our data add to increasing evidence demonstrating the potential for L. intracellularis transmission and infection in wild rodents and feral cats and provide possible evidence of interspecies transmission. The exposure of wild rodents and feral cats provides potential evidence for the spillover of L. intracellularis to wildlife species and raises the question of spillback to horses. Additionally, these animals may represent an indicator of environmental exposure or may be actively involved in the transmission of L. intracellularis to foals by acting as potential reservoir/amplifier hosts. This study is the first to demonstrate the magnitude of L. intracellularis shedding in the feces of wild rodents and feral cats and to indicate the significant infection risk that wild rodents and feral cats pose to naïve horses in South Korea.

Thalassobius litorarius sp. nov., isolated from a tidal flat.

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, belonging to the family Rhodobacteraceae, designated strain MME-075T, was isolated from a tidal flat. Strain MME-075T grew with 1-5% (w/v) NaCl at 20-35 °C and at pH 7-9. Optimal growth occurred with 2% (w/v) NaCl at 25-30 °C and at pH 7. The dominant respiratory quinone was ubiquinone-10, whereas summed feature 8 (C18:1ω7c and/or C18:1ω6c), 11-methyl C18:1ω7c, and C16:0 were the major fatty acids. The major polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an unidentified lipid. The genomic DNA G+C content was 62.1 mol%. The highest 16S rRNA gene sequence similarity values were between strain MME-075T and Thalassobius aestuarii, Thalassococcus lentus, Thalassobius maritimus and Shimia marina and were 97.6, 97.5, 97.2 and 96.2%, respectively. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees, based on 16S rRNA gene sequences, revealed that strain MME-075T clustered with species of the genus Thalassobius. Based on phenotypic and phylogenetic taxonomic properties, this strain is proposed as a representative of a novel species of the genus Thalassobius, for which the name Thalassobius litorarius sp. nov. is proposed. The type strain is MME-075T (=KCCM 43143T=JCM 30758T).

Pseudoruegeria aestuarii sp. nov., of the family Rhodobacteraceae, isolated from a tidal flat.

A Gram-stain-negative, non-motile, aerobic and rod-shaped bacterium, designated strain MME-001T, was isolated from the tidal flat of Muui-do in the Republic of Korea. Phylogenetic trees based on the 16S rRNA gene sequence showed that strain MME-001T belonged to the genus Pseudoruegeria in the family Rhodobacteraceae and that it shared the highest 16S rRNA gene sequence similarity with Pseudoruegeria sabulilitoris GJMS-35T (98.0 % similarity of the 16S rRNA gene). Growth of strain MME-001T occurred in the presence of 1.0-7.0 % (w/v) NaCl at 15-40 °C and pH 7.0-9.0, with optimal growth in the presence of 2.0-3.0 % (w/v) NaCl at 25-30 °C and pH 7.0. Ubiquinone-10 was the major respiratory quinone. Major polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an unidentified lipid. The major cellular fatty acids were C18 : 1ω7c and C16 : 0. The genomic DNA G+C content was 62 mol%. DNA-DNA hybridization values between strain MME-001T and P. sabulilitoris KCTC 42111T, 'Pseudoruegeria limi' KCTC 32460, Pseudoruegeria lutimaris KCTC 22690T, Pseudoruegeria aquimaris KCTC 12737T and Pseudoruegeriahaliotis KACC 17214T was 36±5, 57±7, 34±4, 18±5 and 21±3 %, respectively. Based on the phenotypic and phylogenetic taxonomical properties, this strain MME-001T represents a novel species of the genus Pseudoruegeria, for which the name Pseudoruegeria aestuarii sp. nov. is proposed. The type strain is MME-001T (=KCCM 43133T=JCM 30751T).