DIFFERENTIATION OF ECTOTHIORHODOSPIRACEAE BASED ON THEIR FATTY-ACID COMPOSITION

The fatty acid composition of 27 strains from 7 described Ectothiorhod ospira species, including ail type strains, were analyzed and compared using the ''Microbial Identification System''. According to their abi lity to grow in media with 15% total salts and more or to require much lower salt concentrations the comparison of the strains was made in t wo different groups. The strains grown in the established standard med ium for Ectothiorhodospira species at 15% and 25% (w/v) salinity forme d four major clusters. Two of these enclosed strains of E. halophila, the others E. abdelmalekii (one strain) and E. halochloris (3 strains) , respectively. Those strains with salt optima significantly below 10% (w/v) salinity formed three major clusters. The first included strain s of E. mobilis and E. marismortui. The second cluster contained strai ns of E. shaposhnikovii, E. vacuolata and one strain that had been ten tatively identified as E. mobilis but should be considered as a strain of E. shaposhnikovii. The third group contained strains that were ass igned to E. mobilis but should be regarded as a separate and new speci es. The observed similarities support and extend patterns of relations hips obtained by other taxonomic investigations on the basis of a smal ler number of strains.