TOTAL DNA RESTRICTION PATTERN AND QUINONE COMPOSITION OF MEMBERS OF THE FAMILY ECTOTHIORHODOSPIRACEAE

Total DNA restriction pattern analysis was employed to study the genom ic similarities among fifteen strains belonging to the family Ectothio rhodospiraceae. UPGMA analysis produced clusters of electrophoretic re striction patterns corresponding to the species distribution. Two stra ins were separated from the respective clusters of strains belonging t o the same species. The determination of the quinone composition showe d a clear separation between moderately and extremely halophilic strai ns of the family Ectothiorhodospiraceae and was also useful for the di fferentiation of the species. Strain EST8, which has already been desc ribed, without assigning it to a species, was shown to share some simi larities with E. marismortui on the basis of both restriction fingerpr int and quinone content. Our data show that a thorough study of a larg e number of strains is necessary to obtain a more precise description of the taxonomic structure of the family Ectothiorhodospiraceae.