DNA RELATEDNESS AND CHEMOTAXONOMIC FEATURE OF AEROBIC BACTERIOCHLOROPHYLL-CONTAINING BACTERIA ISOLATED FROM COASTS OF AUSTRALIA

Thirty-seven strains of aerobic bacteriochlorophyll (Bchl)-containing bacteria (ABB) isolated previously from the coasts of Australia were compared with the authentic ABB, Erthrobacter and Roseobacter. They were divided into four groups (GI-GIV) on the basis of cell color, absorption spectrum type of Bchl in the near infrared region and cell morphology. Furthermore, some members of GI and GII were separated genetically into 3 and 4 respectively based on the levels of DNA homology, Among the 37 strains tested, only strain OCh273, a strain of GIV, showed comparatively high DNA homologies (ca. 50%) with the type strains of Roseobacter spp., and the other 36 strains showed low DNA homologies (1 to 12%) with the type strains of Erythrobacter longus and Roseobacter spp. The ubiquinone system of all strains was Q-10 and the major cellular fatty acid (CFA) was C-18:1 acid except in five strains. The major CFA in four (OCh208, OCh229, OCh246 and OCh268) of the five strains was C-17:1 and that of the remaining strain (OCh492) was C-16:0 The guanine plus cytosine contents of the DNA of the 37 test strains examined were from 53.0 to 74.8 mol%.