[Oxidation-reduction status of the culture medium during the biosynthesis of amphotericin B]

The possibility of potentiometric estimation of the oxidation-reduction state of the fermentation broth during production of amphotericin B was studied. It was shown that the reduction capacity of the fermentation broth was high and did not change significantly during the antibiotic biosynthesis. It contained electrochemically active compounds in amounts providing stable potentials on the indicator electrodes. Both the platinum and the glass redoxmetric electrodes not sensitive to changes in the level of oxygen dissolved in the fermentation broth might be used for measuring the oxidation potential of the fermentation broth. Investigation of the dynamics of the oxidation potential changing revealed that during the process of amphotericin B biosynthesis the potential changed within wide ranges and every stage of the culture development was characterized by particular direction of the potential changing. This allowed, in combination with other parameters of the process, estimation of physiological activity of the culture at any moment of its growth.