Abstract
Broth cultures of Staph. aureus develop and maintain a reducing potential in the neighborhood of [long dash]0.150 volt at 37.5[degree] C. These cultures reduce K ferricyanide at a constant rate. Further observations indicate that the potentials observed in bacterial cultures are a resultant of rate of activation of substrate molecules and their rate of oxidation. These potentials are therefore closely connected with the metabolic activities of the cells.