Abstract
By culturingStaphylococcus aureusFDA 209P, Nos. 19, 31, and 36 strains in a neutralbouillon broth supplemented with 1, 000 r/ml of streptomycin, SM-small colony mutants were obtained. These mutants were classified into two groups according to the phase of their size, and their biological characters as well as coagulase action were studied. The results are as follows.
1. As for the decomposition of glucose and lactose by these mutants there could be recognized no change of these sugars as with the parent strain, but in the case of decomposition ofd-mannitol there was a tendency of delay.
2. Coagulase action differed considerably according to different strains and also there was a phase of low resistance to sodium chloride.
From these findings it has been deduced that the small colony mutant results from the changes in the metabolic functions ensuing the nutrient requirements necessitated by enzyme inhibitory action of streptomycin.
