Identification of the Psychrophilic Histamine-Producing Marine Bacteria Previously Referred to as the N-group Bacteria

The taxonomic position of the psychrophilic histamine-producing marine bacteria previously referred to as the N-group bacteria, were studied phenotypically and genotypically. These strains were facultatively anaerobic Gram-negative asporogenous coccobacilli, which were motile by means of unsheathed polar flagella. They were also positive for D-glucose fermentation and poly-β-hydroxybutyrate accumulation, and had guanine plus cytosine contents of genomic DNA of 40 to 43 mol%. The N-group bacteria exhibited high levels of genomic DNA hybridization homologyto the type strain of Photobacterium phosphoreum. The phenotypic and genotypic data suggested that the N-group bacteria are members of P. phosphoreum.