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

Abstract

A novel bacterial strain, named HC41(T), was isolated from a cyanobacterial bloom sample and was characterized as Gramstain-negative, rod-shaped and non-motile. According to 16S rRNA phylogenetic analyses, this strain HC41(T) belongs to the family Rhodocyclaceae and is most closely related to Niveibacterium umoris KACC 170621 (=MIC 20591: 98.63%) and Uliginosibacterium gangwonense 5YN10-9(T) (=KACC 116031; 93.64%). The genome size and DNA G+C content of strain HC41(T) 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 HC41(T) and N. umoris KACC 170621 were 81.8, 43.1 and 90.89%, respectively. Additionally, strain HC41(T) exhibited weak catalase and oxidase activities and had no motility (swimming and swarming motilities). The cells grew at 11-40 degrees C (optimum, 30 degrees 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, C-16:0 and summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c: C-16:1 omega 6c and/or C-16:1 omega 7c) were the predominant cellular fatty acids in strain HC41(T) according to fatty acid methyl ester analysis. Based on its genotypic and phenotypic characteristics, strain HC41(T) was identified as representing a novel Niveibacterium species, for which the name Niveibacterium microcysteis sp. nov. is proposed (=KACC 22091(T)=DSM 111425(T)).