Effect of amphotericin B on the metabolism of Aspergillus fumigatus.

Action of amphotericin B on the growth and metabolism of Aspergillus fumigatus has been investigated. The fungus proved to be very sensitive to amphotericin B, showing complete inhibition of growth at 0.5 units/ml. Amphotericin B suppressed the exogenous and endogenous respiration and glycolysis of A. fumigatus as well as the assimilation of various glycolysis and TCA cycle intermediates. Addition of cations and cholesterol failed to reverse the action of amphotericin B. The treated mycelium released a variety of cellular constituents and it is inferred that the antibiotic effects the permeability of A. fumigatus cells. In experiments with 32P labelled mycelium phosphorus compounds leached out in concentrations which were dependent on the antibiotic dose, period of contact, incubation temperature and metabolic state of the fungus.