Flavobacterium endophyticum sp. nov., a nifH gene-harbouring endophytic bacterium isolated from maize root

A novel Gram-stain-negative, aerobic, rod-shaped bacterium, designated strain 522T, was isolated from surface-sterilized root tissue of maize planted in Fangshan District of Beijing, China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belonged to the genus Flavobacterium and showed less than 93.9 % similarity to the type strains of all recognized species of the genus Flavobacterium. The predominant respiratory quinone was menaquinone-6 and the polar lipid profile was composed of the major lipids phosphatidylethanolamine, phosphatidylserine and two unidentified amino lipids. The major fatty acids were C15 : 0, iso-C15 : 0, iso-C15 : 1 G and iso-C16 : 0.The G+C content of the DNA was 37.7 mol%. The results of physiological and biochemical tests and the differences in fatty acid profiles allowed the clear phenotypic differentiation of strain 522T from closely related species of the genus Flavobacterium. Strain 522T therefore represents a novel species within the genus Flavobacterium, for which the name Flavobacterium endophyticum sp. nov. is proposed. The type strain is 522T ( = ACCC 19708T = DSM 29537T).