ENEEGY SUPPLY OF THE CELL 



87 



medium. Neither of these two species maintain the reduction 

 potential very long; it rises slowly in ordinary aerobic cultures. 

 Micr. pyogenes aureus and Corynebacterium diphtheriae have a lower 



Fig. 5. — Relation between reduction potentials and acidity. 



potential in aerobic cultures than in anaerobic. Perhaps they need 

 oxygen to produce the energy required for the maintenance of the 

 potential. With glucose, the potential is not as low as without. 

 Serum prevents a low potential; it probably acts as an oxygen carrier. 



