Flavobacterium oryzagri sp. nov. and Flavobacterium oryzicola sp. nov., isolated from paddy soil

Two bacterial strains, designated M3-11 T and M6-14 T , were isolated from paddy field soils in the Republic of Korea. Cells were aerobic, Gram-stain-negative, rod-shaped and non-flagellated but motile. The strains exhibited optimal growth at 28 °C and pH 7.0 and in the absence of NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains M3-11 T and M6-14 T were placed within the genus Flavobacterium , showing the highest similarity to Flavobacterium zhairuonense A5.7 T (97.98%) and Flavobacterium nitrogenifigens NXU-44 T (98.23 %), respectively. The genomic similarity between two strains and their closely related strains was 39.3 and 51.1 % for digital DNA–DNA hybridization and 90.0 and 93.2 % for orthologous average nucleotide identity, both of which were lower than the thresholds recommended for species delineation. The respiratory quinone was menaquinone-6, and the major polar lipids were phosphatidylethanolamine and aminolipid. The major fatty acids (>10 %) were iso-C 15 : 0 and summed feature 3. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that strains M3-11 T and M6-14 T represent novel species of the genus Flavobacterium , for which the names Flavobacterium oryzagri sp. nov. (type strain M3-11 T =KACC 22761 T =JCM 35942 T ) and Flavobacterium oryzicola sp. nov. (type strain M6-14 T =KACC 22763 T =JCM 35943 T ) are proposed.