Ciceribacter ferrooxidans sp. nov., a nitrate-reducing Fe(II)-oxidizing bacterium isolated from ferrous ion-rich...

A nitrate-reducing Fe(II)-oxidizing bacterial strain, F8825^T, was isolated from the Fe(II)-rich sediment of an urban creek in Pearl River Delta, China. The strain was Gram-negative, facultative chemolithotrophic, facultative anaerobic, non-spore-forming, and rod-shaped with a single flagellum. Phy-logenetic analysis based on 16S rRNA gene sequencing indicated that it belongs to the genus Ciceribacter and is most closely related to C. lividus MSSRFBL1^T (99.4%), followed by C. thiooxidans F43b^T (98.8%) and C. azotifigens A.slu09^T (98.0%). Fatty acid, polar lipid, respiratory quinone, and DNA G + C content analyses supported its classification in the genus Ciceribacter. Multilocus sequence analysis of concatenated 16S rRNA, atpD, glnII, gyrB, recA, and thrC suggested that the isolate was a novel species. DNA-DNA hybridization and genome sequence comparisons (90.88 and 89.86%, for values of ANIm and ANIb between strains F8825^T with MSSRFBL1^T, respectively) confirmed that strain F8825^T was a novel species, different from C. lividus MSSRFBL1^T, C. thiooxidans F43b^T, and C. azotifigens A.slu09^T. The physiological and biochemical properties of the strain, such as carbon source utilization, nitrate reduction, and ferrous ion oxidation, further supported that this is a novel species. Based on the polyphasic taxonomic results, strain F8825^T was identified as a novel species in the genus Ciceribacter, for which the name Ciceribacter ferrooxidans sp. nov. is proposed. The type strain is F8825^T (= CCTCC AB 2018196^T = KCTC 62948^T).