Niveibacterium microcysteis sp. nov., isolated from a cyanobacterial bloom sample.

Abstract

A novel bacterial strain, named HC41T, was isolated from a cyanobacterial bloom sample and was characterized as Gram-stain-negative, rod-shaped and non-motile. According to 16S rRNA phylogenetic analyses, this strain HC41T belongs to the family Rhodocyclaceae and is most closely related to Niveibacterium umoris KACC 17062T (=MIC 2059T; 98.63 %) and Uliginosibacterium gangwonense 5YN10-9 T (=KACC 11603T; 93.64 %). The genome size and DNA G+C content of strain HC41T were 4.8 Mbp and 64.17 mol%, respectively. Moreover, the average nucleotide identity, digital DNA-DNA hybridization and amino acid identity values between strain HC41T and N. umoris KACC 17062T were 81.8, 43.1 and 90.89 %, respectively. Additionally, strain HC41T exhibited weak catalase and oxidase activities and had no motility (swimming and swarming motilities). The cells grew at 11-40 °C (optimum, 30 °C), pH 5.5-8.0 (optimum, pH 7) and with 0-1.0 % (w/v) NaCl (optimum, 0 % NaCl) in Reasoner's 2A medium. Its major respiratory quinone was ubiquinone-8 and its major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Furthermore, C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; C16 : 1 ω6c and/or C16 : 1 ω7c) were the predominant cellular fatty acids in strain HC41T according to fatty acid methyl ester analysis. Based on its genotypic and phenotypic characteristics, strain HC41T was identified as representing a novel Niveibacterium species, for which the name Niveibacterium microcysteis sp. nov. is proposed (=KACC 22091T=DSM 111425T).