150 



THE ACTINOMYCETES, Vol. I 



acid has been reported in *S'. griseus and in 

 certain *S'. lavendulae fermentations, and 

 acetic acid in others. These acids have been 

 looked upon as transitory products accumu- 

 lating under fermentation conditions and 

 inhibiting normal growth of the actinomy- 

 cete. They are further metabolized by these 

 organisms if the fermentation period is ex- 

 tended or if aeration is increased. In certain 



100 



S. fradiae cultures where the medium is 

 poorly buffered, sufficient acetic acid accu- 

 mulates to inhibit further growth and me- 

 tabolism (Hubbard and Thornberry). The 

 accumulated acetate is metabolized when 

 the pH of the medium is raised. 



Wang et al. (1958) carried out time course 

 experiments on the oxidation of C^^-labeled 

 glucose and acetate by 8. griseus. With 



O RESTING CELLS 

 A GROWING CELLS 



TIME 



HOURS 



i 



Figure 70. Utilization of acetate-1-C" by growing and resting cells of S. gnseus (Heprodnced from: 

 Gilmour, C. M. et al. J. Bacteriol. 69: 721, 1955). 



