Rosenbergiella nectarea gen. nov., sp. nov., in the family Enterobacteriaceae, isolated from floral nectar

Gram-negative, rod-shaped, oxidase-negative, facultatively anaerobic, yellow-orange-pigmented and motile bacterial strains, designated 8N4^T, 9N2 and 10N3, were isolated from flower nectar of Amygdalus communis (almond) and Citrus paradisi (grapefruit). The 16S rRNA gene sequences of the strains shared highest sequence similarity of 97.0% with that of Phaseolibacter flectens ATCC 12775^T and lower similarity with sequences from other type strains of genera of the Enterobacteriaceae. A polyphasic approach that included determination of phenotypic properties and phylogenetic analysis based on 16S rRNA, gyrB, rpoB and atpD gene sequences supported the classification of strains 8N4^T, 9N2 and 10N3 within a novel species in a novel genus in the family Enterobacteriaceae. Strain 8N4^T, and the reference strains of the novel species, grew at 4-356C (optimum, 28-30 6C), with 0-5.0% NaCl (optimum, 3% NaCl) and with 0-60% sucrose (optimum, 10-25% sucrose). Their major cellular fatty acids were C_{16: 0}, C_{17: 0} cyclo, C_{18: 1}v7c and summed feature 3 (C_{16: 1}v7c and/or iso-C_{15: 0} 2-OH). The DNA G+C content of strain 8N4^T was 46.8 mol%. On the basis of phenotypic properties and phylogenetic distinctiveness, the floral nectar isolates are classified within a novel species in a new genus in the family Enterobacteriaceae, for which the name Rosenbergiella nectarea gen. nov., sp. nov. is proposed. The type strain of Rosenbergiella nectarea is 8N4^T (5LMG 26121^T5DSM 24150^T).