Oxidation-reduction potentials of cultures of haemolytic streptococci. I

Abstract

The fall in potential during growth is much greater with peptone-infusion broth than with tryptic-digest broth. In freshly boiled broth the potential falls more rapidly and to a lower level than in unboiled broth. In vigorously aerated cultures, H2O2 appears after 16-24 hrs. growth and the electrode potential is high in every case. Glucose and lactic acid retard H2O2 formation. A low concentration of H2O2 in broth causes a long lag period, but after this the normal potential-time curve is obtained.