Flavobacterium cyanobacteriorum sp. nov., isolated from cyanobacterial aggregates in a eutrophic lake

A Gram-reaction-negative, aerobic, non-flagellated, non-gliding, rod-shaped and yellow-pigmented bacterium, designated strain TH021T, was isolated from cyanobacterial aggregates in a eutrophic lake, Taihu Lake, China. Optimal growth occurred at pH 7.0 (range: 5.0–10.0), 28 °C (range, 4–32 °C) and 0 % (w/v) NaCl (range, 0–1.0 %) in Reasoner’s 2A broth. No growth was observed at 37 °C. The cells were found to be positive for oxidase and catalase activities. The major respiratory quinone was menaquinone-6. The major fatty acids (>10 %) were identified as iso-C15 : 0 and C16 : 1ω7c/C16 : 1ω6c. The major polar lipid was phosphatidylethanolamine. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was affiliated with the genus Flavobacterium , with the highest sequence similarity found to Flavobacterium hauense BX12T (94.92 %), followed by Flavobacterium suzhouense XIN-1T (94.85 %), Flavobacterium arcticum SM1502T (94.79 %) and Flavobacterium beibuense F44-8T (94.30 %). The genomic G+C content of strain TH021T was 41.9 mol% based on total genome calculations. Average nucleotide identities and digital DNA–DNA hybridizations values for complete genomes ranged from 69.4 to 72.8 and 18.0 to 23.8 % between strain TH021T and strains within the genus Flavobacterium . The phenotypic, chemotaxonomic and phylogenetic properties, and genome analysis suggested that strain TH021T represents a novel species within the genus Flavobacterium , for which the name Flavobacterium cyanobacteriorum sp. nov. is proposed. The type strain is TH021T (=LMG 29720T=CGMCC 1.16325T).