Psychromonas japonica sp. nov., Psychromonas aquimarina sp. nov., Psychromonas macrocephali sp. nov. and Psychromonas ossibalaenae sp. nov., psychrotrophic bacteria isolated from sediment adjacent to sperm whale carcasses off Kagoshima, Japan.

Four novel species of psychrotrophic bacteria were isolated from sediment adjacent to sperm whale carcasses off Kagoshima, Japan, at a depth of 228-250 m. Cells of the five isolated strains, JAMM 0394(T), JAMM 0404(T), JAMM 0415(T), JAMM 0700 and JAMM 0738(T), were Gram-negative, rod-shaped, non-sporulating and motile by means of a single polar flagellum. The novel strains were able to produce isoprenoid quinone Q-8 as the major component. The predominant fatty acids were C(16 : 0) and C(16 : 1). Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel strains represent a separate lineage within the genus Psychromonas. The G+C contents of the novel strains were 38.8-42.8 mol%. DNA-DNA hybridization values between these strains and reference strains of the genus Psychromonas were significantly lower than that generally accepted as the threshold for the phylogenetic definition of species. The names Psychromonas japonica sp. nov. (type strain JAMM 0394(T)=JCM 14783(T)=ATCC BAA-1525(T)), Psychromonas aquimarina sp. nov. (type strain JAMM 0404(T)=JCM 14784(T)=ATCC BAA-1526(T)), Psychromonas macrocephali sp. nov. (two strains, type strain JAMM 0415(T)=JCM 14785(T)=ATCC BAA-1527(T)) and Psychromonas ossibalaenae sp. nov. (type strain JAMM 0738(T)=JCM 14786(T)=ATCC BAA-1528(T)) are proposed.