Flavobacterium aurantiibacter sp. nov., an orange-pigmented bacterium isolated from cyanobacterial aggregates in a eutrophic lake

Abstract

A bacterial strain, designated TH167T, was isolated from cyanobacterial aggregates in eutrophic Lake Taihu in China. Cells were observed to be slightly curved rod-shaped, motile by gliding, aerobic, Gram-stain-negative, proteorhodopsin-containing. Optimal growth was obtained at pH 7.0 (range: 6.0-9.0), 28 °C (range: 4-32 °C) and 0 % (w/v) NaCl (range: 0-2.0 %) in Reasoner's 2A broth. No growth was observed at 37 °C. The cells were found to be positive for catalase and oxidase activities. The major fatty acids (>10 %) were identified as iso-C15 : 0, iso-C15 : 1 G and anteiso-C15 : 0. The major polar lipids of the isolate comprised phosphatidylethanolamine, one unidentified phospholipid and two unidentified aminolipids. The major respiratory quinone was menaquinone-6. The genomic G+C content of strain TH167T was 40.4 mol% based on total genome calculations. Based on similarities of 16S rRNA gene sequences, strain TH167T was affiliated with the genus Flavobacterium, exhibiting the highest sequence similarities to Flavobacterium eburneum SA31T (94.16 %), Flavobacterium yanchengensehgT (94.09 %) and Flavobacterium lacus NP180T (93.95 %). The phenotypic, chemotaxonomic and phylogenetic properties, and genome analysis suggested that strain TH167T represented a novel species within the genus Flavobacterium, for which the name Flavobacterium aurantiibacter sp. nov. is proposed. The type strain is TH167T (=CGMCC 1.15805T=LMG 29719T).