Description of Prasinibacter corallicola gen. nov., sp. nov., a zeaxanthin-producing bacterium isolated from stony coral Porites lutea

Thermal stress is considered one of the main causes of mass scleractinian coral degradation; however, it is still unknown how corals can adapt to future global warming. In this study, 11 strains of coral-associated Flavobacteria were shown to produce zeaxanthin, a carotenoid antioxidant, which may help coral holobionts to alleviate thermal stress. In addition, a novel zeaxanthin-producing Flavobacterium, designated R38^T, was identified using polyphasic taxonomy. Although strain R38^T shared a maximum 16S rRNA gene sequence similarity of 93% with Mesoflavibacter aestuarii KYW614^T, phylogenetic analyses based on whole genome and 16S rRNA gene sequences revealed that strain R38^T forms a distinct branch in a robust cluster composed of strain R38^T and Leptobacterium flavescens KCTC 22160^T under the family Flavobacteriaceae. Strain R38^T exhibited average nucleotide identities of 70.2% and 72.5% for M. aestuarii KYW614^T and L. flavescens KCTC 22160^T, respectively. The only detected respiratory quinone was menaquinone 6 (MK-6). The genomic DNA G + C content was 33.2 mol%. The major polar lipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, one unidentified ninhydrin phospholipid, three unidentified ninhydrin-positive lipids, and three unidentified lipids. The major cellular fatty acids were iso - C_15: 0, iso - C_15: 0 ω6c, C_16:2 DMA, and C_13:1 ω3c. The distinct biochemical, chemotaxonomic, phylogenetic, and phylogenomic differences from validly published taxa suggest that strain R38^T represents a new species of a new genus, for which Prasinibacter corallicola gen. nov., sp. nov. is proposed. The type strain R38^T (= MCCC 1K03889^T = KCTC 72444^T).

Identification of a novel bacterial taxon associated with bovine mastitis showing a close evolutionary relationship with Elizabethkingia sp

Recently, the characteristics of prevalent bacterial pathogens causing bovine mastitis have become increasingly complicated, and many commensal or unusual bacterial species have been isolated from milk samples of cows with mastitis. Strain JS20170427COW was isolated dominantly from the milk of Holstein Friesian cows with mastitis in Jiangsu province in China. Colonies of this strain showed a hillock-like protrusion, with a pale-yellow color at the protrusion and a transparent edge, 4-5 mm in diameter after cultivation at 37 °C for 24 h on 5% sheep blood-enriched agar. Although 16 s rRNA analysis showed the closest relationship with the family Flavobacteriaceae containing Elizabethkingia spp., Riemerella sp. and Soonwooa buanensis, the bacterial species of strain JS20170427COW could not be identified adequately because it had a sequence identity of less than 95 % in 16 s rRNA when compared with all the known species of the family Flavobacteriaceae. Unexpectedly, both the first and re-sequencing data determined the whole genome size of strain JS20170427COW to be 2.69 Mb, which is different from the above three closest bacterial species. Therefore, we hypothesized that strain JS20170427COW is a novel taxon of Flavobacteriaceae. Further identification using conserved genes, single-nucleotide polymorphisms (SNPs), phylogenetic and average nucleotide identity analyses based on whole genome data suggested that JS20170427COW was more likely to be an Elizabethkingia-like strain, but that it does not belong to the Elizabethkingia genus. Comparison of the predicted open reading frames (ORFs) revealed that strain JS20170427COW encodes more special genes than Elizabethkingia species. In summary, we identified a novel Flavobacteriaceae taxon showing a close relationship with Elizabethkingia subspecies, which has potential pathogenicity in bovine mastitis.

Flavicella sediminum sp. nov., isolated from marine sediment

A novel, Gram-stain-negative, motile, flagellated, aerobic, rod-shaped (0.5-0.7 µm wide and 1.0-1.2 µm long) and faint-yellow strain, designated ALS 84^T, was isolated from marine sediment sampled at Ailian bay, Rongcheng, PR China. Growth occurred in the presence of 1-3 % (w/v) NaCl (optimum, 2 % NaCl), at pH 4.0-8.0 (pH 6.0-7.0) and at 8-30 °C (28 °C). The genome size was 4.37 Mbp. The G+C content of the genomic DNA was 33.6 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences suggested that strain ALS 84^T belongs to the genus Flavicella within the family Flavobacteriaceae, and is most closely related to Flavicella marina (95.6 % similarity). The major fatty acids (>10 %) were iso-C_{15 : 0} 3-OH (22.9 %), iso-C_{15 : 0} (14.0 %) and C_{16 : 0} (10.9 %). The major polar lipids were phosphatidylethanolamine and three unidentified lipids. Menaquinone-6 (MK-6) was identified as the respiratory quinone. On the basis of the phenotypic, phylogenetic and chemotaxonomic data obtained in the study, strain ALS 84^T is considered to represent a novel species of the genus Flavicella, for which the name Flavicella sediminum sp. nov. is proposed. The type strain of the novel species is strain ALS 84^T (=KCTC 62398^T=MCCC 1K03480^T).

Spongiiferula fulva gen. nov., sp. nov., a Bacterium of the Family Flavobacteriaceae Isolated from a Marine Sponge

A Gram stain-negative, strictly aerobic, brown-pigmented, non-motile, rod-shaped, chemoheterotrophic bacterial strain-designated A6F-119(T) was isolated from a marine sponge (Rhabdastrella sp.). Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the new strain represented a member of the family Flavobacteriaceae of the phylum Bacteroidetes and that it showed highest sequence similarity (93 %) to Tenacibaculum maritimum NBRC 15946(T). The strain could be differentiated phenotypically from the recognized members of the family Flavobacteriaceae. The DNA G + C content of strain A6F-119(T) was determined to be 30.8 mol%; MK-6 was identified as the major menaquinone; and the presence of iso-C15:0, iso-C17:0 3-OH, and C16:1 ω7c and/or C16:1 ω6c as the major (>10 %) cellular fatty acids. A polar lipid profile was present consisting of phosphatidylethanolamine, an unidentified aminolipid, and three unidentified lipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel genus for which the name Spongiiferula fulva gen. nov., sp. nov. is proposed. The type strain of S. fulva is A6F-119(T) (= KCTC 42752(T) = NBRC 111402(T)).

Aurantivirga profunda gen. nov., sp. nov., isolated from deep-seawater, a novel member of the family Flavobacteriaceae

A Gram-stain-negative, aerobic, proteorhodopsin-containing, orange, rod-shaped bacterium, designated SAORIC-234T, was isolated from deep seawater in the Pacific Ocean. 16S rRNA gene sequence analysis revealed that the strain could be affiliated with the family Flavobacteriaceae of the phylum Bacteroidetes and shared less than 94.6 % similarity with other species of the family with validly published names. The phenotypic characteristics of this novel isolate, such as growth properties and enzyme activities, could be differentiated from those of other species. The strain was non-motile, oxidase-positive and catalase-negative. The G+C content of the genomic DNA was determined to be 34.8 mol% and menaquinone-6 (MK-6) was the predominant isoprenoid quinone. The predominant fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C16 : 0 3-OH, iso-C17 : 0 3-OH and iso-C15 : 0 3-OH. The major polar lipids comprised phosphatidylethanolamine, three unknown aminolipids and three unknown lipids. On the basis of the taxonomic data collected in this study, it was concluded that strain SAORIC-234T represents a novel genus and species in the family Flavobacteriaceae, for which the name Aurantivirga profunda gen. nov., sp. nov. is proposed. The type strain of the type species, Aurantivirga profunda sp. nov., is SAORIC-234T ( = NBRC 110606T = KACC 18400T).

Pseudofulvibacter geojedonensis gen. nov., sp. nov., a polysaccharide-degrading member of the family Flavobacteriaceae isolated from seawater, and emended description of the genus Fulvibacter

A Gram-negative, non-spore-forming, aerobic, non-flagellated, non-gliding rod, designated YCS-9T, was isolated from seawater in the South Sea, South Korea. Strain YCS-9T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain YCS-9T fell within the family Flavobacteriaceae and formed a cluster with Fulvibacter tottoriensis MTT-39T with a bootstrap resampling value of 75.4 %. Strain YCS-9T showed 92.3 % 16S rRNA gene sequence similarity to F. tottoriensis MTT-39T and 89.0–93.7 % sequence similarity to the other strains used in the phylogenetic analysis. Strain YCS-9T contained MK-6 as the only menaquinone and iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids. The major polar lipids were one unidentified lipid and one unidentified aminolipid. The DNA G+C content was 34.2 mol%. Strain YCS-9T could be differentiated from F. tottoriensis NBRC 102624T by differences in fatty acid composition, polar lipid profile and some phenotypic properties. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain YCS-9T represents a novel species in a new genus within the phylum Bacteroidetes , for which the name Pseudofulvibacter geojedonensis gen. nov., sp. nov. is proposed. The type strain of Pseudofulvibacter geojedonensis is YCS-9T ( = KCTC 23884T  = CCUG 62114T). An emended description of the genus Fulvibacter is also presented.

Hwangdonia seohaensis gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from a tidal flat sediment

A Gram-staining-negative, aerobic, non-flagellated, non-gliding and rod-shaped bacterial strain, HD-3(T), was isolated from a tidal flat sediment of Hwangdo in the Yellow Sea, South Korea. Strain HD-3(T) grew optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain HD-3(T) joined the cluster comprising the type strains of Jejuia pallidilutea and Hyunsoonleella jejuensis. Strain HD-3(T) exhibited 16S rRNA gene sequence similarity values of 93.8% to each of the type strains of J. pallidilutea and Hyunsoonleella jejuensis. Strain HD-3(T) contained MK-6 as the only menaquinone and iso-C(15:0), iso-C(15:1) G, iso-C(17:0) 3-OH and iso-C(15:0) 3-OH as the major fatty acids. The polar lipid profile of strain HD-3(T), which contained phosphatidylethanolamine and one unidentified lipid as major components and one unidentified phospholipid as a significant component, differed slightly from those of the type strains of J. pallidilutea and Hyunsoonleella jejuensis. The DNA G+C content of strain HD-3(T) was 42.3 mol%. Differential phenotypic and chemotaxonomic properties and phylogenetic data of strain HD-3(T) demonstrated that this strain is distinguishable from J. pallidilutea and Hyunsoonleella jejuensis. On the basis of the data presented, strain HD-3(T) is considered to represent a novel genus and species, for which the name Hwangdonia seohaensis gen. nov., sp. nov. is proposed. The type strain is HD-3(T) ( =KCTC 32177(T) =CCUG 63246(T)).

Aureitalea marina gen. nov., sp. nov., a member of the family Flavobacteriaceae, isolated from seawater

An irregular rod-shaped, non-gliding, yellow-pigmented bacterium was isolated from seawater from the western North Pacific Ocean near Japan. The strain, designated S1-66T, was Gram-negative, obligately aerobic, heterotrophic and oxidase-positive. Growth occurred in the presence of 1–4 % NaCl, with optimum growth at 2 % NaCl. The strain grew at 15–30 °C, with optimum growth at 20–25 °C. The G+C content of genomic DNA was 48.1 mol% (HPLC). The predominant isoprenoid quinone was MK-6 and the major cellular fatty acids were iso-C15 : 0 (26.4 %), iso-C15 : 1 (20.3 %) and iso-C17 : 0 3-OH (14.2 %). Phylogenetic trees generated by using 16S rRNA gene sequences revealed that strain S1-66T belongs to the family Flavobacteriaceae and showed 94.2 % sequence similarity to the most closely related type strain, Ulvibacter antarcticus IMCC3101T. On the basis of phenotypic and phylogenetic features, S1-66T is classified in a novel genus and species within the family Flavobacteriaceae , for which the name Aureitalea marina gen. nov., sp. nov. is proposed. The type strain of Aureitalea marina is S1-66T ( = NBRC 107741T  = KCTC 23434T).

Isolation from Tannery Wastewater and Characterization of Bacterial Strain Involved in Nonionic Surfactant Degradation

A bacterial strain OPQa3 capable of utilizing nonylphenol polyoxyethylene (NPnEO) as sole carbon source was isolated from water samples collected from tannery waste treatment plant suffered long-time application of NPnEO by enrichment method. It was preliminarily identified as Brevundimonas sp. (most similar to Brevundimonas diminuta (EU434566.1)), according to the observation of morphological characteristics, physiological-biochemical tests and the similarity analysis of its 16S rDNA gene sequence. Inoculated 2% of OPQa3 suspension, to give a final OD600of approximately 0.70, to inorganic salt medium in which the initial concentration of NPnEO was 746 mg•L-1, degradation test showed that, the degradation rate of strain OPQa3 was 84.5% within 120 hours, the optimum temperature was 30°C while the optimum pH value was about 7, and the growth period was of 24 hours.