The facultatively aerobic, non-hydrogenotrophic, iron (Fe0)-corroding, nitrate-reducing Prolixibacter sp. strain MIC1-1(T) was characterized for representation of a novel species of the genus Prolixibacter. Strain MIC1-1(T) grew optimally at 35-37 °C, at pH 6.5 and with 2% (w/v) NaCl. Strain MIC1-1(T) also grew fermentatively on some pentoses, hexoses, disaccharides and soluble starch. Succinic acid was the major end-product from D-glucose fermentation. Strain MIC1-1(T) was differentiated from the type strain of Prolixibacter bellariivorans by cell size, optimum growth temperature, range of temperature and NaCl for growth, and nitrate reduction. On the basis of phenotypic features and the phylogenetic position, a novel species of the genus Prolixibacter is proposed for strain MIC1-1(T), to be named Prolixibacter denitrificans sp. nov. The type strain is MIC1-1(T) ( = JCM 18694(T) = NBRC 102688(T)= DSM 27267(T)). Emended descriptions of the genus Prolixibacter and Prolixibacter bellariivorans are also provided.