THE EFFECT OF THE OXIDATION-REDUCTION CHARACTER OF THE MEDIUM ON THE GROWTH OF AN AEROBIC FORM OF BACTERIA

Abstract

These studies indicate that the oxidation-reduction (O-R) potentials of the medium affect materially the ability of certain aerobic bacteria to initiate growth, as evidenced by growth about O-R centers fixed in petri plate cultures. In shake-agar test-tube cultures, growth levels were established by the bacteria at various depths in the tubes, depending on the O-R potential of the medium. The growth level appeared nearer the surface in the more reduced media. Physical aids, such as addition of filter paper, sand, etc., to liquid media, seemed to enhance the ability of the organisms to overcome unfavorable O-R potentials. Large inocula were more effective than small.