Mole % guanine plus cytosine (GC%) of butyrate-producing anaerobic cocci was determined. Experiments were carried out to clarify DNA-DNA homology among these organisms and evaluate the present taxonomy of anaerobic cocci. The following results were obtained.
The GC% of butyrate-producing
Peptococcus was in a range from 23.8 to 50.8. Especially, that of
P. asaccharolyticus and
P. prevotii was variable. The results of experiments to clarify DNA-DNA homology amog butyrate producing
Peptococcus organisms suggest that the taxonomy of these organisms may have to be revised.
The GC% of
“Gaffkya anaerobia”, the specific name of which has been rejected and the taxonomical position of which not yet proposed, was very close to that of
P. asaccharolyticus or
P. prevotii, but the first organism was genetically distinct from these organisms.
Coprococcus and
Gemmiger requiring carbohydrate to grow were different from other butyrate-producing cocci, judging from the results of experiments on both GC% and DNA-DNA homology.
Acidaminococcus and
Megasphaera, both of which are gram-negative and butyrate-producing anaerobic cocci, had similar GC%, but they were genetically different from each other.
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