a n d Institute of Physical a n d Chemical Research, Wako-shi, Saitama 351,2 J a p a n The deoxyribonucleic acid homologies among 33 strains of coryneform bacteria with various cell wall types reflected the previous grouping of these organisms by Yamada and Komagata on the bases of the mode of cell division, principal amino acids in the cell wall, and the base composition of deoxyribonucleic acid. In addition, the following four homology clusters were found: (i) six strains of corynebacteria with a glycolyl type of cell wall, (ii) four strains of glutamic acidproducing bacteria, (iii) two strains of Breuibacterium linens, and (iv) three strains of coryneform bacteria containing LL-diaminopimelic acid in the cell wall.The aerobic, nonsporeforming, irregularly shaped, gram-positive rods of the genera Corynebacterium, Arthro bacter, Cellulomonas, Curtobacterium (32), Breuibacterium, and Microbacterium are referred to as coryneform bacteria (19). Phenotypic characteristics seem to be of little value in the taxonomy of coryneform bacteria, but chemotaxonomic information on the chemical composition of cells has been useful in this regard. Yamada and Komagata (33) divided coryneform bacteria into seven groups, mainly on the bases of the mode of cell division (14), principal amino acids in the cell wall (30), and deoxyribonucleic acid (DNA) base composition (32). These groupings have subsequently been supported by the cell wall peptidoglycan types (21), the phospholipid compositions of the cells (16), and the menaquinone systems (4, 29) of these organisms. Studies on the DNA homologies of Corynebacterium renale and phenotypically related strains (lo), cheese coryneforms and soil arthrobacters (6), plant pathogenic coryneform bacteria (25), arthrobacters and brevibacteria (23), and cellulomonads (24) have been reported. However, little information is available on the DNA homology of aerobic coryneform bacteria in general.This report deals with DNA homologies among representative strains of coryneform bacteria selected from each of the groups described by Yamada and Komagata (33) and compares the results with the chemotaxonomic characteristics of these organisms.
MATERIALS AND METHODSBacterial strains. The bacterial strains studied were selected from those previously studied by Komagata et al. (14) and . A Caseobacter polymorphus strain, a species recently established by Crombach (7), was also studied. The strains studied are listed in Table 1, together with their strain numbers, several corresponding culture collection designations, and their chemotaxonomic profiles. Names which are not on the Approved Lists of Bacterial Names, 1980 (22) are enclosed within quotation marks.As references for the DNA homology experiments, generally one strain was chosen from each group. However, for group 1, which has a wide range of DNA base compositions, four strains-Corynebacterium equi CNF 002, Corynebacterium uitarumen CNF 008 (17), Breuibacterium ammoniagenes CNF 012, and Corynebacterium glutamicum CNF 016-were selected as referenc...