Flavobacterium panici sp. nov. isolated from the rhizosphere of the switchgrass Panicum virgatum
Résumé
A Gram-staining-negative non endospore-forming strain, PXU-55 T , was isolated from the rhizosphere of the switchgrass Panicum virgatum and studied in detail to determine its taxonomic position. The results of 16S rRNA gene sequence analysis indicated that the isolate represented a member of the genus Flavobacterium . The isolate shared highest 16S rRNA gene sequence similarities with the type strains of Flavobacterium chungangense (98.78 %) and Flavobacterium chilense (98.64 %). The average nucleotide identity (ANI) and in silico DNA–DNA hybridization (isDDH) values between the PXU-55 T genome assembly and the ones of the most closely related type strains of species of the genus Flavobacterium were 87.3 and 31.9% ( Flavobacterium defluvii ), and 86.1 and 29.9% ( Flavobacterium johnsoniae ). Menaquinone MK-6 was the major respiratory quinone. As major polar lipids, phosphatidylethanolamine, an ornithine lipid and the unidentified polar lipids L2, L3 and L4 lacking a functional group were found. Moderate to minor amounts of another ornithine lipid, the unidentified lipid L1 and a glycolipid were present, as well. The major polyamine is sym -homospermidine. The fatty acid profiles contained major amounts of iso-C 15:0 , iso-C 15:0 3-OH, iso-C 17:0 3-OH, C 15:0 , summed feature 3 (C 16:1 ω7 c and/or iso-C 15:0 2-OH) and various hydroxylated fatty acids in smaller amounts, among them iso C 16:0 3-OH, C 16:0 3-OH and C 15:0 3-OH, which supported the classification of the isolate as a member of the genus Flavobacterium . Physiological and biochemical characterisation and ANI calculations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of the strain. For this reason, we propose that strain PXU-55 T (=CIP 111646 T =CCM 8914 T ) represents a novel species with the name Flavobacterium panici sp. nov.