Elstera cyanobacteriorum sp. nov., a novel bacterium isolated from cyanobacterial aggregates in a eutrophic lake.

A bacterial strain, TH019, was isolated from cyanobacterial aggregates in a eutrophic lake, Taihu Lake, China. Cells were observed to be slightly curved rod-shaped and stained Gram-negative. Optimal growth was obtained at pH 7.0 (range, 5.0-9.0) and 28 °C (range, 20-37 °C) in R2A broth. The cells were found to be positive for oxidase and catalase activities, nitrate reduction and denitrification. The major respiratory quinone was ubiquinone Q-10. The major fatty acids were identified as C18 : 1 ω6c/C18 : 1 ω7c and C18 : 1 2OH. The 16S rRNA gene sequence of strain TH019 was phylogenetically related to Elstera litoralis Dia-1 (97.9 % similarity). The genomic G+C content of strain TH019 was 62.4 mol% based on total genome calculations. Average nucleotide identity and digital DNA-DNA hybridization values for complete genomes were 78.8 and 19.8 %, respectively, between strain TH019 and Elstera litoralis Dia-1. The phenotypic, chemotaxonomic and phylogenetic properties, and genome analysis suggested that strain TH019 represented a novel species within the genus Elstera, for which the name Elstera cyanobacteriorum sp. nov. is proposed. The type strain is TH019 (=CGMCC 1.15802=LMG 29721).