Flavobacterium lacunae sp. nov., isolated from a freshwater pond

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

Strain LLJ-11^T, isolated from water sampled from a freshwater stream in Taiwan, was characterized using a polyphasic taxonomy approach. Cells of strain LLJ-11^T 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-11^T is affiliated with species in the genus Flavobacterium. Strain LLJ-11^T was most closely related to Flavobacterium amniphilum KYPY10^T with 98.0 % 16S rRNA gene sequence identity. The DNA-DNA relatedness of strain LLJ-11^T with respect to Flavobacterium species was less than 35 %. Average nucleotide identity and digital DNA-DNA hybridization values between strain LLJ-11^T and the type strains of other closely related Flavobacterium species were 70.0-76.3 % and 21.1-23.9 %, respectively. Strain LLJ-11^T 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-11^T is considered a representative of a novel species within the genus Flavobacterium. The name Flavobacterium amnicola sp. nov. is proposed, with strain LLJ-11^T (=BCRC 81124^T=LMG 30599^T=KCTC 62514^T) as the type strain.

Flavobacterium hydrophilum sp. nov. and Flavobacterium cheongpyeongense sp. nov., isolated from freshwater

Two Gram-stain-negative, non-motile, yellow-pigmented bacterial strains, designated IMCC34758^T and IMCC34759^T, were isolated from freshwater. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains formed a distinct clade within the genus Flavobacterium and they shared 97.9 % sequence similarity. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values (dDDH) between the two strains were 85.5 and 30.2 %, respectively, indicating that they are separate species. The two strains showed ≤98.5 % 16S rRNA gene sequence similarities, 80.6-81.3 % of ANI and 24.7-25.1 % of dDDH values to closely related species of the genus Flavobacterium, indicating that the two strains each represent novel Flavobacteriumspecies. The respiratory quinone detected in both strains was menaquinone-6 (MK-6). The major polar lipids of the two strains were phosphatidylethanolamine, an unidentified aminolipid, an unidentified aminophospholipid and an unidentified polar lipid. The DNA G+C contents of strains IMCC34758^T and IMCC34759^T were 34.0 and 34.1 mol%, respectively. The major fatty acids of the two strains were very similar to each other, comprising iso-C15 : 0, iso-C15 : 1 G, anteiso-C15 : 0 and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). Phenotypic characteristics including enzyme activities and carbon source utilization differentiated the two strains from other Flavobacteriumspecies. Based on these results, strains IMCC34758^T and IMCC34759^T were considered to represent novel species in the genus Flavobacterium, for which the names Flavobacterium hydrophilum (IMCC34758^T=KACC 19591^T=NBRC 113423^T) and Flavobacterium cheongpyeongense (IMCC34759^T=KACC 19592^T=NBRC 113424^T) are proposed, respectively.

Chemical and molecular characterization of metabolites from Flavobacterium sp

In this study, a Flavobacterium sp. is isolated from natural spring, and identified using molecular techniques. Extracellular and intracellular secondary metabolites are identified using solid phase microextraction gas chromatography-mass spectrometry and ultra performance liquid chromatography. Cytotoxic activity of the extracellular compounds produced by the Flavobacterium sp. and quercetin as the standard are measured using ECV304 human endothelial cells in vitro. Our results show that Flavobacterim sp. isolate has the highest percentage of similarity with Flavobacterium cheonhonense strain ARSA-15 (99%). Quercetin is detected as the major extracellular compound produced by the Flavobacterium sp. Methanol extract of Flavobacterium sp. resulted in a higher cell viability results when compared to DMSO extracts. Computational chemistry approach was used and it has been found that polar solvent (methanol) contributed to higher antioxidant activity. In conclusion, Flavobacterium sp. can be used to produce quercetin for industrial purposes.

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 HS916^T was closely related to members of the genus Flavobacterium, exhibiting the highest sequence similarities with Flavobacterium glycines Gm-149^T (96.4%), followed by F. granuli Kw05^T (96.3%), F. fluminis 3R17^T (96.3%), F. aquicola TMd3a3^T (96.2%), and F. nitratireducens N1^T (96.2%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HS916T was placed in a monophyletic cluster with F. nitratireducens N1^T and F. fluminis 3R17^T. The predominant fatty acids (> 5% of the total) of strain HS916^T were iso-C_15:0, anteiso-C_15:0, iso-C_15:0 3-OH, C_17:1ω6с, C_16:0 3-OH, iso-C_17:0 3-OH, and summed feature 3 (C_16:1ω7с and/or C_16:1ω6с). 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 HS916^T was 34.9 mol%. Based on polyphasic analyses, strain HS916^T 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 19448^T = JCM 32368^T).