| Abstract |
Two aerobic, Gram-stain-negative, non-motile and rod-shaped bacterial strains designated GGG-R5T and M4-18T were isolated from flowers of golden wave (Coreopsis grandiflora) and rice paddy soil, respectively in the Republic of Korea. Both strains were pigmented and produced flexirubin-type pigments. Based on phylogenetic analysis using 16S rRNA gene sequence, both strains were placed within the genus Mucilaginibacter with M. agri R11T and M. jinjuensis YC7004T both being the closest relatives to GGG-R5T (97.7%) and in case of M4-18T, M. ginsenosidivorax KHI28T (98.5%) was the nearest neighbor. Characteristic to genus Mucilaginibacter, the major cellular fatty acids in both strains were iso-C15:0, iso-C17:0 3-OH, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c); menaquinone-7 was the major menaquinone and phosphatidylethanolamine was the major polar lipid observed. Comparison of genome sequences with the other members of Mucilaginibacter indicated orthologous average nucleotide identity (orthoANI) at 73.3-73.5% for GGG-R5T and 78.9-88.5% for M4-18T. Digital DNA-DNA hybridization (dDDH) values ranged at 19.1-19.7% between GGG-R5T and its neighbor species. In case of M4-18T, the observed range was at 21.9-36.6%. Considering the 16S rRNA similarity, orthoANI and dDDH values as well as comparison of phenotypic and chemotaxonomic characteristics indicated that both strains belonged to genus Mucilaginibacter but were distinctly distinguishable from previously described species. The strains GGG-R5T and M4-18T, therefore represent distinct novel species for which names Mucilaginibacter florum GGG-R5T and Mucilaginibacter oryzagri M4-18T are proposed. The type strains are GGG-R5T (= KACC 22063T = JCM 36590T) and M4-18T (= KACC 22773T = JCM 35894T).
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