Amphritea japonica sp. nov. and Amphritea balenae sp. nov., isolated from the sediment adjacent to sperm whale carcasses off Kagoshima, Japan.

Two novel species were isolated from the sediment adjacent to sperm whale carcasses off Kagoshima, Japan, at a depth of about 230 m. The isolated strains, JAMM 1866(T), JAMM 1548 and JAMM 1525(T), were Gram-negative, rod-shaped, non-spore-forming and motile by means of a single polar or bipolar flagellum. Phylogenetic analysis based on 16S rRNA gene sequences of strains JAMM 1866(T) and JAMM 1548 indicated a relationship to the symbiotic bacterial clone R21 of Osedax japonicus (100 % sequence similarity) and all three isolates were closely related to Amphritea atlantica (97.7-97.8 % similarity) within the class Gammaproteobacteria. The novel isolates were able to produce isoprenoid quinone Q-8 as the major component. The predominant fatty acids were C(16 : 0), C(16 : 1) and C(18 : 1), with C(12 : 1) 3-OH present in smaller amounts. The DNA G+C contents of the three isolated strains were about 47 mol%. Based on differences in taxonomic characteristics, the three isolated strains represent two novel species of the genus Amphritea for which the names Amphritea japonica sp. nov. (type strain JAMM 1866(T)=JCM 14782(T)=ATCC BAA-1530(T); reference strain JAMM 1548) and Amphritea balenae sp. nov. (type strain JAMM 1525(T)=JCM 14781(T)=ATCC BAA-1529(T)) are proposed.