Flavobacterium acetivorans sp. nov. and Flavobacterium galactosidilyticum sp. nov., psychrotolerant flavobacteria isolated from cultivated fish.

Two yellow-coloured strains, F-29T and F-340T, were isolated from fish farms in Antalya and Mugla in 2015 and 2017 during surveillance studies. The 16S rRNA gene sequence analysis showed that both strains belong to the genus Flavobacterium. A polyphasic approach involving a comprehensive genome analysis was employed to ascertain the taxonomic provenance of the strains. The overall genome-relatedness indices of digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) between the strains and the other members of the genus Flavobacterium were found to be well below the established thresholds of 70 and 95 %, respectively. The whole-genome-based phylogenetic analysis revealed that strain F-29T is closely related to Flavobacterium granuli (dDDH 39.3 % and ANI 89.4 %), while strain F-340T has a close relationship with the type strain of Flavobacterium pygoscelis (dDDH 25.6 % and ANI 81.5 %). Both strains were psychrotolerant with an optimum growth temperature of 25 °C. The chemotaxonomic characteristics of the strains were typical of the genus Flavobacterium. Both strains had phosphatidylethanolamine, aminolipids and unidentified lipids in their polar lipid profile and MK-6 as the isoprenoid quinone. The major fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The genome size of the strains was 3.5 Mb, while G+C contents were 35.3 mol% for strain F-29T and 33.4 mol% for strain F-340T. Overall, the characterizations confirmed that both strains are representatives of two novel species within the genus Flavobacterium, for which the names Flavobacterium acetivorans sp. nov. and Flavobacterium galactosidilyticum sp. nov. are proposed, with F-29T (JCM 34193T=KCTC 82253T) and F-340T (JCM 34203T=KCTC 82263T) as the type strains, respectively.

Comprehensive genome analysis of five novel flavobacteria: Flavobacterium piscisymbiosum sp. nov., Flavobacterium pisciphilum sp. nov., Flavobacterium flavipigmentatum sp. nov., Flavobacterium lipolyticum sp. nov. and Flavobacterium cupriresistens sp. nov.

Eight isolates were obtained through a study on culture-dependent bacteria from fish farms and identified as members of the genus Flavobacterium based on pairwise analysis of the 16S rRNA gene sequences. The highest pairwise identity values were calculated as 98.8 % for strain F-30 T and Flavobacterium bizetiae, 99.0 % for strain F-65 T and Flavobacterium branchiarum, 98.7 % for strain F-126 T and Flavobacterium tructae, 98.2 % for strain F-323 T and Flavobacterium cupreum while 99.7 % identity level was detected for strain F-70 T and Flavobacterium geliluteum. In addition, strains F-33, Fl-77, and F-70 T shared 100 % identical 16S rRNA genes, while strains F-323 T and Fl-318 showed 99.9 % identity. A polyphasic approach including comparative analysis of whole-genome data was employed to ascertain the taxonomic provenance of the strains. In addition to the morphological, physiological, biochemical and chemotaxonomic characteristics of the strains, the overall genome-relatedness indices of dDDH and ANI below the established thresholds confirmed the classification of the strains as five novel species within the genus Flavobacterium. The comprehensive genome analyses of the strains were also conducted to determine the biosynthetic gene clusters, virulence features and ecological distribution patterns. Based on the polyphasic characterisations, including comparative genome analyses, it is concluded that strains F-30 T, F-65 T, F-70 T, F126T and F-323 T represent five novel species within the genus Flavobacterium for which Flavobacterium piscisymbiosum sp. nov. F-30 T (=JCM 34194 T = KCTC 82254 T), Flavobacterium pisciphilum sp. nov. F-65 T (=JCM 34197 T = KCTC 82257 T), Flavobacterium flavipigmentatum sp. nov. F-70 T (Fl-33 = Fl-77 = JCM 34198 T = KCTC 82258 T), Flavobacterium lipolyticum sp. nov. F-126 T (JCM 34199 T = KCTC 82259 T) and Flavobacterium cupriresistens sp. nov. F-323 T (Fl-318 = JCM 34200 T = KCTC 82260 T), are proposed.

Flavobacterium coralii sp. nov., a marine bacterium isolated from coral culture seawater.

A Gram-stain-negative, non-motile, strictly aerobic, rod-shaped bacterium, with one polar flagellum and named D11R37T, was isolated from coral culture seawater of Acropora digitifera. Strain D11R37T grew with 0-6 % (w/v) NaCl (optimum, 0.5%), at 10-41 °C (optimum, 28 °C) and at pH 6.0-7.0 (optimum, 7.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain D11R37T formed a lineage within the genus Flavobacterium, and it was distinct from the most closely related species Flavobacterium suzhouense XIN-1T and Flavobacterium suaedae G16-7T with 16S rRNA gene sequences similarities of 95.97% and 95.48 %. The major respiratory quinone was menaquinone-6. The polar lipids comprised one phosphatidylethanolamine, two aminolipids and one unknown polar lipid. The predominant fatty acids (more than 10 % of total fatty acids) were iso-C15 : 0 (18.0%), iso-C17 : 0 3-OH (11.9 %) and summed feature 3 (10.9 %). The DNA G+C content was 41.3 mol%. Based on polyphasic taxonomic data, strain D11R37T is considered to represent a novel species within the genus Flavobacterium, for which the name Flavobacterium coralii sp. nov. is proposed. The type strain is D11R37T (=KCTC 82968T=MCCC 1K06440T).

Flavobacterium hydrocarbonoxydans sp. nov., isolated from polluted soil.

This paper presents a polyphasic taxonomic study of a Gram-stain-negative bacterium designated GA093T, a soil isolate capable of benzo(α)pyrene degradation. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain GA093T is a member of the genus Flavobacterium, and formed an independent phylogenetic line while clustering with the type strains of Flavobacterium hibernum, Flavobacterium branchiarum and Flavobacterium hydatis. Strain GA093T was facultatively anaerobic, and could grow at 4-33 °C (optimum, 30 °C), at pH 6-11 (optimum, pH 7) and in the presence of 0-2 % (w/v) NaCl (optimum, 0 %). Strain GA093T was capable of producing acid from various carbon sources, which was comparable to other related species of Flavobacterium. The strain contained MK-6 as the only isoprenoid quinone, iso-C15 : 0 as the major cellular fatty acid, phosphatidylethanolamine and phosphatidylinositol as diagnostic polar lipids, and sym-homospermidine as the major polyamine. The chemotaxonomic properties of strain GA093T were consistent with the general properties of Flavobacterium except the presence of phosphatidylinositol, which distinguished it from other related species. The total stretch of the obtained genome of GA093T was 5.05 Mbp, and the DNA G+C content was 34.79 mol%. The genome contained genes potentially related to the degradation of aromatic hydrocarbons. On the basis of the present polyphasic analysis, strain GA093T was found to have properties that distunguished it as representing a novel species of the genus Flavobacterium, for which the name Flavobacterium hydrocarbonoxydans sp. nov. is proposed. The type strain is GA093T (=KCTC 72594T=LMG 31760T).

Phenotypic and Genetic Characterization of Flavobacterium psychrophilum Recovered from Diseased Salmonids in China.

Flavobacterium psychrophilum, the etiological agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome, causes great economic losses in salmonid aquaculture worldwide. Recent molecular studies have uncovered important epidemiological and ecological aspects of this pathogen; however, such data are lacking for F. psychrophilum populations affecting aquaculture in China. Herein, F. psychrophilum phenotype, genotype, and virulence were characterized for isolates recovered from epizootics in multiple salmonid aquaculture facilities across China. Thirty-one F. psychrophilum isolates, originating from four provinces and three host fish species, were predominantly homogeneous biochemically but represented 5 sequence types (STs) according to multilocus sequence typing (MLST) that belonged to clonal complex CC-ST10 or 3 newly recognized singleton STs. PCR-based serotyping classified 19 and 12 F. psychrophilum isolates into molecular serotypes 1 and 0, respectively, showing an obvious relationship with host species. Antimicrobial susceptibility analysis via broth microdilution revealed reduced susceptibility to enrofloxacin, flumequine, and oxolinic acid, moderate susceptibility to gentamicin, erythromycin, and florfenicol, and variable susceptibility to ampicillin and oxytetracycline. In vivo challenge experiments confirmed the ability of two representative Chinese F. psychrophilum isolates to induce typical signs of BCWD and mortality in 1-year-old rainbow trout (Oncorhynchus mykiss). Findings collectively demonstrate (i) that BCWD outbreaks in China studied thus far are caused by F. psychrophilum lineages that are common on other continents (e.g., CC-ST10) and others that have not been reported elsewhere (e.g., ST355, ST356, ST357), (ii) that F. psychrophilum molecular serotypes distinguish isolates from different host fish species, even within STs, and (iii) reduced F. psychrophilum antimicrobial susceptibility against compounds used for BCWD control in China. IMPORTANCE Flavobacterium psychrophilum causes substantial economic losses in salmonid aquaculture worldwide. Although this bacterium is also believed to be a disease source in China, published reports of its presence do not yet exist. Herein, F. psychrophilum was linked to multiple disease outbreaks in several salmonid aquaculture facilities within four Chinese provinces, and polyphasic characterization revealed that most isolates were genetically distinct from strains recovered on other continents. Analyses further revealed the predominating molecular serotypes, antimicrobial susceptibility profiles, and pathogenic potential of two representative recovered isolates. Collectively, the results presented here provide important data on the epidemiology and disease ecology of F. psychrophilum in China and pave the way for targeted prevention and control methods to be pursued in the future.

Flavobacterium muglaense sp. nov. isolated from internal organs of apparently healthy rainbow trout.

Two yellow-pigmented isolates, F-60T and F-392, were isolated from the internal organs of an apparently healthy rainbow trout (Oncorhynchus mykiss). The strains were identified as members of the genus Flavobacterium based on the results of 16S rRNA gene sequence analysis. Strains F-60T and F-392 had the highest 16S rRNA gene sequence identity level of 97.4 % to the type strain of Flavobacterium crassostreae LPB0076T. A polyphasic taxonomic approach including phenotypic, chemotaxonomic and genomic characterization was employed to ascertain the taxonomic position of the strains within the genus Flavobacterium. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity based on blast (ANIb) values for strains F-60T and F-392 were calculated as 100 %. However, dDDH and ANI analyses between the strains and their close neighbours confirmed that both strains represent a novel species in the genus Flavobacterium. The strains shared the highest dDDH and ANIb levels of 23.3 and 77.9%, respectively, with the type strain of Flavobacterium frigidarium DSM 17623T while those values for F. crassostreae LPB0076T were obtained as 21.4-21.5 % and 76.3 %. The DNA G+C content of the strains was 34.5 mol%. Chemotaxonomic and phylogenomic analyses of these isolates confirmed that both strains are representatives of a novel species for which the name Flavobacterium muglaense sp. nov. is proposed, with F-60T as the type strain (=JCM 34196T=KCTC 82256T).

Flavobacterium turcicum sp. nov. and Flavobacterium kayseriense sp. nov. isolated from farmed rainbow trout in Turkey.

During a study on culturable microorganisms from fish farms, four yellow-pigmented gram negative, rod shaped isolates, F-47T, F-339T, F-380 and F-400, were recovered from rainbow trout samples exhibiting clinical signs. Based on 16S rRNA gene sequence analysis, the strains were identified as members of the genus Flavobacterium. Strains F-47T and F-380 shared the highest 16S rRNA gene sequence identity level of 97.6% with the type strain of Flavobacterium frigoris DSM 15719T while strains F-339T and F-400 shared the highest identity level of 97.6% with the type strain of F. caseinilyticum AT-3-2T. A polyphasic taxonomic approach including phenotypic and genomic characterization as well as whole-cell MALDI-TOF mass spectrometry analyses was employed to ascertain the taxonomic position of the strains within the genus Flavobacterium. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses between strains F-47T, F-339T and their close neighbours F. frigoris DSM 15719T and F. caseinilyticum AT-3-2T, respectively, confirmed that both strains represent novel species in the genus Flavobacterium. The DNA G+C contents of the strains F-47T and F-339T are 34.3% and 35.3%, respectively. It can be concluded on the basis of polyphasic characterization as well as pairwise genome comparisons that the strains F-47T and F-339T represent two novel species within the genus Flavobacterium, for which Flavobacterium kayseriense sp. nov. F-47T (=JCM 34195T=KCTC 82255T) and Flavobacterium turcicum sp. nov. F-339T (=JCM 34202T=KCTC 82262T) are proposed, respectively.

Flavobacterium salilacus sp. nov., isolated from surface water of a hypersaline lake, and descriptions of Flavobacterium salilacus subsp. altitudinum subsp. nov. and Flavobacterium salilacus subsp. salilacus subsp. nov.

Two yellow-pigmented, Gram-stain-negative, aerobic, rod-shaped bacteria were isolated from the water of the hypersaline Chaka Salt Lake (strain SaA2.12T) and sediment of Qinghai Lake (strain LaA7.5T), PR China. According to the 16S rRNA phylogeny, the isolates belong to the genus Flavobacterium, showing the highest 16S rRNA sequence similarities to Flavobacterium arcticum SM1502T(97.6-97.7 %) and Flavobacterium suzhouense XIN-1T(96.5-96.6 %). Moreover, strains SaA2.12T and LaA7.5T showed 99.73 % 16S rRNA sequence similarity to each other. Major fatty acids, respiratory quinones and polar lipids detected in these isolates were iso-C15 : 0, menaquinone-6 and phosphatidylethanolamine, respectively. Strains SaA2.12T and LaA7.5T showed significant unique characteristics between them as well as between the closest phylogenetic members. The highest digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between SaA2.12T and its closest neighbours were 25.3 and 82.8 %, respectively; whereas these values (highest) between LaA7.5T and its closest members were 25.2 and 82.8 %, respectively. The dDDH and ANI values between strains SaA2.12T and LaA7.5T were calculated as 75.9 and 97.2 %, respectively. Therefore, based on polyphasic data, we propose that strain SaA2.12T represents a novel species with the name Flavobacterium salilacus sp. nov., with the type strain SaA2.12T (=KCTC 72220T=MCCC 1K03618T) and strain LaA7.5T as a subspecies within novel Flavobacterium salilacus with the name Flavobacterium salilacus subsp. altitudinum subsp. nov., with the type strain LaA7.5T (=KCTC 72806T=MCCC 1K04372T). These propositions automatically create Flavobacterium salilacus subsp. salilacus subsp. nov. with SaA2.12T (=KCTC 72220T=MCCC 1K03618T) as the type strain.

Flavobacterium sandaracinum sp. nov., Flavobacterium caseinilyticum sp. nov., and Flavobacterium hiemivividum sp. nov., novel psychrophilic bacteria isolated from Arctic soil.

This study presents taxonomic description of strains LB-D12T, AT-3-2T, AT-3-7, and TSA-D2T isolated from Arctic soil. All strains were psychrophilic, Gram-stain-negative, aerobic, non-motile, and rod-shaped. Phylogenetic analysis showed that these strains belonged to the genus Flavobacterium. Strains LB-D12T, AT-3-2T and AT-3-7 were closest to Flavobacterium psychrolimnae LMG 22018T (98.5-98.8% sequence similarity). Strain TSA-D2T was closest to Flavobacterium degerlachei DSM 15718T (98.3 % sequence similarity). These strains shared common chemotaxonomic features comprising MK-6 as a sole quinone, phosphatidylethanolamine as the principal polar lipid, and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C16 : 0 3-OH, C15 : 1ω6c, iso-C16 : 0, and anteiso-C15 : 0 as the main fatty acids. The ANI and dDDH values between these novel isolates and their closest relatives were below the cut-off values of 95 and 70 %, respectively used for species demarcation. The DNA G+C content of all strains ranged from 34.2 to 34.6 mol%. The obtained polyphasic taxonomic data suggested that the isolated strains represent novel species within the genus Flavobacterium, for which the names Flavobacterium sandaracinum sp. nov. (type strain LB-D12T=KEMB 9005-737T=KACC 21180T=NBRC 113784T), Flavobacterium caseinilyticum sp. nov. (type strain AT-3-2T=KEMB 9005-738T=KACC 21176T=NBRC 113785T), and Flavobacterium hiemivividum sp. nov. (type strain TSA-D2T=KEMB 9005-741T=KACC 21179T=NBRC 113788T) are proposed.

Flavobacterium cellulosilyticum sp. nov., a novel psychrophilic bacterium isolated from Arctic soil.

A novel psychrophilic, light-yellow-coloured, aerobic, Gram-stain-negative, rod-shaped, non-motile bacterium, designated strain AR-3-4T was isolated from a sample of Arctic soil. Strain AR-3-4T grew at 0-25 °C, pH 6.0-9.0 and 0-1.0 % (w/v) NaCl concentration. The 16S rRNA gene sequence analysis showed that strain AR-3-4T belonged to the genus Flavobacterium, with nearest phylogenetic neighbour being Flavobacterium fluvii H7T (97.5 % sequence similarity). The strain comprised phosphatidylethanolamine as the main polar lipid, MK-6 as predominant respiratory quinone, and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), anteiso-C15 : 0 and iso-C15 : 0 as the major fatty acids. The average nucleotide identity and in silico DNA-DNA hybridization values between strain AR-3-4T and closest members were below the threshold values of 95 % and 70 %, respectively. The DNA G+C content was 33.0 mol%. Based on the polyphasic taxonomic data, the novel species Flavobacterium cellulosilyticum sp. nov. is proposed with the type strain AR-3-4T (=KEMB 9005-740T=KACC 21171T=NBRC 113787T).

Flavobacterium humi sp. nov., a flexirubin-type pigment producing bacterium, isolated from soil.

A yellow pigmented, Gram-stain-negative, strictly aerobic, rod-shaped, motile by means of gliding, catalase and oxidase positive bacterium, designated strain DS2-AT, was isolated from soil. Growth was observed at 4-32°C (optimum, 28°C), pH 6-9 (optimum, 7.0), and with 0-0.25% (w/v) NaCl (optimum, 0%). Phylogenetic analysis of 16S rRNA gene sequence revealed that strain DS2-AT belonged to the genus Flavobacterium and was most closely related to Flavobacterium aquatile LMG 4008T (96.4%), Flavobacterium terrae DSM 18829T (95.6%), Flavobacterium vireti THG-SM1T (95.5%), Flavobacterium inkyongense IMCC27201T (95.4%), Flavobacterium brevivitae TTM-43T (95.2%), and Flavobacterium cucumis DSM 18830T (95.2%). Strain DS2-AT produces flexirubin-type pigments. The major fatty acids were iso-C15:0, iso-C17:0 3-OH, and iso-C15:0 3-OH. The major respiratory quinone was identified as menaquinone-6. The major polar lipid was found to be phosphatidylethanolamine. The average nucleotide identity values between strain DS2-AT and selected taxa, F. aquatile LMG 4008T, F. terrae DSM 18829T, and F. cucumis DSM 18830T, were 72, 72.7, and 71.6%, respectively. The draft genome of strain DS2-AT has a number of 14 contigs, scaffold N50 of 476,310 bp and a total size of 3,563,867 bp. Additionally, strain DS2-AT contains 3,127 of gene, 41 of tRNA, 6 of rRNA, and 3 of ncRNA. The DNA G + C content of stain DS2-AT was 40.7 mol%. Based on phylogenetic and phenotypic analyses, strain DS2-AT is considered as a novel species of the genus Flavobacterium, for which the name Flavobacterium humi sp. nov., (type strain DS2-AT = KACC 19715T = JCM 32786T) has been proposed.

Flavobacterium zhairuonensis sp. nov., a gliding bacterium isolated from marine sediment of the East China Sea.

A yellow pigmented, Gram-stain-negative, aerobic bacterium designated A5.7T was studied to evaluate the taxonomic position following the modern polyphasic approach. The strain was isolated from sediments near Zhairuo Island, which is situated in the East China Sea. Cells were non-spore forming rods without flagella but showed motility by gliding. Growth was observed at 15-35°C (optimum 28°C), pH 6.0-9.0 (optimum pH 6.5) and 0-2% (w/v) NaCl (optimum 0-0.5%) in LB broth. The major respiratory quinone of A5.7T was menaquinone 6. The major polar lipid of A5.7T was phosphatidylethanolamine and the predominant fatty acids (> 5%) were iso-C15:0, iso-C17:0 3-OH, C15:1ω6c, iso-C15:0 3-OH, iso-C15:1 G, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Flavobacterium and shares the highest sequence similarities with Flavobacterium sharifuzzamanii A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T (98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%), Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans THG 01T (97.6%), and Flavobacterium foetidum CJ42T (97.6%). Digital DNA-DNA hybridization and average nucleotide identity values between the strain and its closest phylogenetic neighbors showed the ranges from 19.6 to 34.1% and 73.7 to 87.9%, respectively. Therefore, based on polyphasic characteristics, strain A5.7T represents a novel species of the genus Flavobacterium for which the name Flavobacterium zhairuonensis sp. nov. is proposed. The type strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).

Flavobacterium cerinum sp. nov., isolated from Arctic tundra soil.

In the present paper, we describe a new species of the genus Flavobacterium, designated as strain 1E403T, which was isolated from a soil sample collected from the Arctic. Strain 1E403T was Gram-stain-negative, yellow-pigmented, rod-shaped, gliding and aerobic. Growth occurred at 4-37 °C (optimum, 28 °C), pH 6.0-9.0 (pH 7.0) and with 0-2 % (w/v) NaCl (0 %) on modified marine agar 2216. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain 1E403T was affiliated with the genus Flavobacterium and was more closely related to Flavobacterium subsaxonicum DSM 21790T (96.6 %) than to other species. In silico genomic comparisons, including average nucleotide identity and the digital DNA-DNA hybridization values, showed 73.9 % and 18.8 % identity to the closest relative Flavobacterium subsaxonicum DSM 21790T, respectively. The average amino acid identity value between strain 1E403T and Flavobacterium aquatile DSM 1132T was 63.8 %. The DNA G+C content of the strain was 36.8 %, while the sole respiratory quinone was menaquinone-6. Iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) were the major fatty acids (>10 %) of strain 1E403T. The polar lipid profile of strain 1E403T contained phosphatidylethanolamine, four unidentified aminolipids and two unidentified phospholipids. Based on the phenotypic characteristics, chemotaxonomic characteristics and phylogenetic inference, strain 1E403T represents a novel species of the genus Flavobacterium, and we propose the name Flavobacterium cerinum sp. nov. The type strain of Flavobacterium cerinum sp. nov. is 1E403T (=KCTC 62960T=MCCC 1H00356T).

Flavobacterium silvisoli sp. nov., isolated from forest soil.

During a study of the Kyonggi University soil bacterial diversity, an aerobic, non-motile, Gram-stain-negative, non-spore-forming, rod-shaped, yellow pigmented bacterium, designated strain RD-2-33T was isolated. Strain RD-2-33T grew optimally at 28-35 °C and pH 7.0-7.5; hydrolysed gelatin and DNA; and tolerated 1 % of NaCl. A phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain RD-2-33T clustered with the genus Flavobacterium. The closest member was Flavobacterium dankookense ARSA-19T (97.1 % sequence similarity) and Flavobacterium cheonhonense ARSA-15T (96.7 %). Sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine and an unidentified polar lipid. The major cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, and iso-C15 : 1 G. The DNA G+C content was 38.6 mol%. The average nucleotide identity (ANI) and in silico DNA-DNA hybridisation relatedness between strain RD-2-33T and Flavobacterium dankookense DSM 25687T were 75.2 and 19.3 %, respectively. Based on the polyphasic and phylogenetic data, strain RD-2-33T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium silvisoli sp. nov. is proposed. The type strain is RD-2-33T (=KEMB 9005-742T=KACC 21178T=NBRC 113789T).

Flavobacterium amnicola sp. nov., isolated from a sub-tropical stream.

Strain LLJ-11T, isolated from water sampled from a freshwater stream in Taiwan, was characterized using a polyphasic taxonomy approach. Cells of strain LLJ-11T were Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and formed translucent yellow colonies. Optimal growth occurred at 25 °C, pH 7 and 0 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain LLJ-11T is affiliated with species in the genus Flavobacterium. Strain LLJ-11T was most closely related to Flavobacterium amniphilum KYPY10T with 98.0 % 16S rRNA gene sequence identity. The DNA-DNA relatedness of strain LLJ-11T with respect to Flavobacterium species was less than 35 %. Average nucleotide identity and digital DNA-DNA hybridization values between strain LLJ-11T and the type strains of other closely related Flavobacterium species were 70.0-76.3 % and 21.1-23.9 %, respectively. Strain LLJ-11T contained iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0) as the predominant fatty acids. The major isoprenoid quinone was MK-6. The polar lipid profile consisted of phosphatidylethanolamine, three uncharacterized aminophospholipids and two uncharacterized phospholipids. The major polyamine was homospermidine. The DNA G+C content was 34.8 mol%. On the basis of the phylogenetic inference and phenotypic data, strain LLJ-11T is considered a representative of a novel species within the genus Flavobacterium. The name Flavobacterium amnicola sp. nov. is proposed, with strain LLJ-11T (=BCRC 81124T=LMG 30599T=KCTC 62514T) as the type strain.

Molecular detection of microbial colonization in cervical mucus of women with and without endometriosis.

PROBLEM: Intrauterine microbial colonization and its association with the pathogenesis of endometriosis via an innate immune cascade have been reported. As a potential source of microbial transmission, information on microbial colonization in cervical mucus is unknown. We investigated pattern of microbiota in the cervical mucus collected from women with and without endometriosis using next-generation sequencing (NGS) technology. METHOD OF STUDY: Cervical mucus samples were collected from women with (n = 30) and without (n = 39) endometriosis. The communities of microbiota in cervical mucus in the endometriosis group and the control group were examined by Gram staining and NGS targeting the V5-V6 region of 16S ribosomal RNA gene. Copy number of some target bacteria was detected by real-time PCR. RESULTS: We confirmed visual presence of bacteria in cervical mucus by Gram staining. NGS analysis showed that distribution of microbiota was similar in cervical mucus of women with and without endometriosis regardless of the phases of the menstrual cycle. In addition to predominant Lactobacilli spp., the populations of Corynebacterium, Enterobacteriaceae, Flavobacterium, Pseudomonas, and Streptococcus were increased in the endometriosis group. Of them, Enterobacteriaceae and Streptococcus were identified as the more significant candidates in the endometriosis group than in controls by real-time PCR (P < 0.05 for each). CONCLUSION: Our NGS analysis of cervical mucus indicated that among a variable microbiota, two candidates (Enterobacteriaceae and Streptococcus) were more frequently detected in women with endometriosis. Further investigation is needed to elucidate a mechanistic link of these bacteria in the pathophysiology of endometriosis.

Flavobacterium dasani sp. nov., a psychrotolerant bacterium isolated from Arctic soil.

A novel yellow-colored, Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive, and rod-shaped psychrotolerant bacterium, designated strain PLR-18-3T, was isolated from Arctic soil and was subjected to polyphasic taxonomic study. Cells were able to grow at 0-30 °C, pH 6.0-10.5, and 0-3.0% (w/v) NaCl concentration. Based on the 16S rRNA gene sequence analysis, this Arctic strain belonged to the genus Flavobacterium, with the closest neighbor being Flavobacterium noncentrifugens R-HLS-17T (96.2% sequence similarity). The strain contained MK-6 as a sole respiratory quinone, phosphatidylethanolamine as the major polar lipid, and summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C15:0, iso-C15:0 G, iso-C17:0 3-OH, iso-C15:0 3-OH, anteiso-C15:0, and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl) as the predominant fatty acids. The DNA G + C content was 37.9 mol%. On the basis of polyphasic data, strain PLR-18-3T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium dasani sp. nov. is proposed. The type strain is PLR-18-3T (=KEMB 9005-713T=KACC 19627T=NBRC 113347T).

Flavobacterium knui sp. nov., a novel member of the family Flavobacteriaceae.

A Gram-stain negative, non-motile, rod-shaped bacterial strain, designated 2-56T, was isolated from water and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2-56T belongs to the family Flavobacteriaceae in the phylum Bacteroidetes and is closely related to Flavobacterium paronense KNUS1T (98.4%) and Flavobacterium collinsense 4-T-2T (96.7%). The G + C content of the genomic DNA of strain 2-56T was 33.4 mol%. The isolate contained MK-6 as the predominant respiratory quinone, and iso-C15:1 G (15.9%), iso-C15:0 (15.8%), iso-C17:0 3-OH (10.7%), and iso-C15:0 3-OH (9.6%) were the major fatty acids. The major polar lipids were phosphatidylethanolamine and an unidentified lipid. The phenotypic and chemotaxonomic data support the affiliation of strain 2-56T with the genus Flavobacterium. However, the DNA-DNA relatedness between the isolate and F. paronense and F. collinsense were 35.7 and 21.5%, respectively, clearly showing that strain 2-56T is not related to them at the species level. Strain 2-56T could be clearly differentiated from its close neighbours on the basis of its phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2-56T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium knui sp. nov. is proposed. The type strain is 2-56T (= KCTC 62061T = JCM 32247T).

Flavobacterium parvum sp. nov., isolated from soil polluted by sewer water.

A novel Gram-stain-negative, motile by means of gliding, and short rod-shaped bacterium, designated HS916T, was isolated from soil polluted by sewer water in Cheonan-si, South Korea. Growth occurred at 10-35°C (optimum 30°C), pH 6.0-8.0 (optimum pH 7.0), and 0-1% sodium chloride (NaCl, w/v). Based on similarities of 16S rRNA gene sequences, strain HS916T was closely related to members of the genus Flavobacterium, exhibiting the highest sequence similarities with Flavobacterium glycines Gm-149T (96.4%), followed by F. granuli Kw05T (96.3%), F. fluminis 3R17T (96.3%), F. aquicola TMd3a3T (96.2%), and F. nitratireducens N1T (96.2%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HS916T was placed in a monophyletic cluster with F. nitratireducens N1T and F. fluminis 3R17T. The predominant fatty acids (> 5% of the total) of strain HS916T were iso-C15:0, anteiso-C15:0, iso-C15:0 3-OH, C17:1ω6с, C16:0 3-OH, iso-C17:0 3-OH, and summed feature 3 (C16:1ω7с and/or C16:1ω6с). The major polar lipids of the strain comprised phosphatidylethanolamine, unidentified aminolipids, and five unidentified lipids. The predominant respiratory quinone and the major polyamine were menaquinone-6 (MK-6) and symhomospermidine, respectively. The DNA G + C content of strain HS916T was 34.9 mol%. Based on polyphasic analyses, strain HS916T represents a novel species belonging to the genus Flavobacterium, for which the name Flavobacterium parvum sp. nov. is proposed. The type strain is HS916T (= KACC 19448T = JCM 32368T).

Characterization of Flavobacterium aquimarinum sp. nov., a halotolerant bacterium isolated from seawater.

A novel, aerobic, Gram-stain-negative, non-motile, non-spore forming, rod-shaped bacterium, designated strain Dol 15-39T, was isolated from a seawater sample near Geoje Island in the South Sea, Republic of Korea. The strain was found to be oxidase-negative and catalase-positive. The isolate was observed to grow at temperatures from 4 to 37°C, at salinities of up to 7%, and at pH levels from 6 to 9; moreover, it was not able to degrade starch, DNA, esculin, or tyrosine. Phylogenetic analysis based on 16S rRNA gene sequences showed that Dol 15-39T was most closely related to Flavobacterium jumunjinense HME7102T with a sequence similarity of 97.3%. However, the levels of DNA-DNA relatedness between Dol 15-39T and the most closely related species were much lower than 70%, confirming that they represented distinct genomic species. The genomic DNA G + C content of Dol 15-39T was calculated to be 32.6 mol%. MK-6 was the predominant respiratory quinine, while iso-C15:0 (25.0%), iso-C15:1 G (17.0%), and iso-C17:0 3-OH (10.4%) were the major cellular fatty acids. Phosphatidylethanolamine was identified as a major polar lipid, while various unidentified aminolipids and polar lipids were also detected. Based on polyphasic taxonomic data, Dol 15-39T represents a novel species of the genus Flavobacterium, for which the name F. aquimarinum sp. nov. is proposed. The type strain is accessible under the culture collection numbers (KEMB 9005-617T = JCM 31930T).