Flavobacterium humidisoli sp. nov., isolated from riverside soil

A novel Gram-stain-negative, yellow-pigmented, non-motile and rod-shaped bacterial strain designated MMS21-Er5^T was isolated and subjected to polyphasic taxonomic characterization. MMS21- Er5^T could grow at 4-34 °C (optimum, 30 °C), at pH 6-8 (optimum, pH 7) and in the presence of 0-2% NaCl (optimum, 1 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that MMS21- Er5^T showed low levels of sequence similarities with other species, as the highest similarity of 97.83 % was observed with Flavobacterium tyrosinilyticum THG DN8.8^T, then 97.68 % with 'Flavobacterium ginsengiterrae' DCY 55 and 97.63 % with Flavobacterium banpakuense 15F3^T, which were well below the suggested cutoff for species distinction. The whole genome sequence of MMS21-Er5^T consisted of a single contig of 5.63 Mbp, and the DNA G+C content was 34.06 mol%. The in-silico DNA-DNA hybridization and orthologous average nucleotide identity values were highest with Flavobacterium tyrosinilyticum KCTC 42726^T (45.7 and 91.92% respectively). The predominant respiratory quinone for the strain was menaquinone-6 (MK-6), the major cellular fatty acid was iso-C_15 : 0, and the diagnostic polar lipids were phosphatidylethanolamine and phosphatidyldiethanolamine. The combination of physiological and biochemical tests clearly distinguished the strain from related species of the genus Flavobacterium. On the basis of these results, strain MMS21-Er5^T evidently represents a novel species of the genus Flavobacterium, for which the name Flavobacterium humidisoli sp. nov. is proposed (type strain=MMS21-Er5^T=KCTC 92256^T =LMG 32524^T).