DNA relatedness and chemotaxonomic feature of aerobic bacteriochlorophyll-containing bacteria isolated from coasts of australia

Abstract

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 C18:1acid except in five strains. The major CFA in four (OCh208, OCh229, OCh246 and OCh268) of the five strains was C17:1and that of the remaining strain (OCh492) was C16:0-The guanine plus cytosine contents of the DNA of the 37 test strains examined were from 53.0 to 74.8 mol%. © 1994, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.