A Gram-negative, non-spore-forming, aerobic rods, strain YIC4121T, was isolated from root nodule of Sesbania cannabina grown in Dongying (Yellow River Delta), Shandong Province, PR China. Based on phylogenetic analysis of 16 S rRNA gene sequences, strain YIC4121T was assigned to the genus Agrobacterium with 99.7, 99.3, 99.0, 98.8 and 98.7% sequence similarities to Agrobacterium radiobacter LMG140T, A. pusense NRCPB10T, A. arsenijevicii KFB 330T, A. nepotum 39/7T and A. larrymoorei ATCC51759T. Analysis of the concatenated housekeeping genes (recA-atpD-glnII), showed lower sequence similarities (≤94.6%) between strain YIC4121T and other recognized Agrobacterium species. Strain YIC4121T shared whole-genome average nucleotide identities (ANI) 87.94, 91.27 and 77.42%, with A. pusense NRCPB10T, A. radiobacter LMG140T and A. larrymoorei ATCC51759T. The predominant cellular fatty acids were C19:0 cyclo ω8c, summed feature 2 (C12:0 aldehyde/unknown 10.9525), summed feature 8 (C18:1 ω7c/C18:1 ω6c), C16:0 3 OH and C16:0. The G + C content of strain YIC4121T was 59.80 mol%. Tween 80, lactulose, citric acid, α-ketoglutaric acid, glycyl-L-glutamic acid and 2, 3-butanediol could not be utilized as carbon source, distinguishing strain YIC4121T from the other related species. Based on the distinctly genetic and phenotypic dissimilarity, a novel species Agrobacterium deltaense sp. nov. is proposed with YIC4121T (=HAMBI 3654T = LMG 29283T) as the type strain.
Keywords: ANI; Agrobacterium; Sesbania cannabina.