EFFECTS OF AMPHOTERICIN-B ON GLUCOSE-METABOLISM IN CANDIDA-ALBICANS BLASTOSPORES EVIDENCED BY C-13 NMR

Candida albicans blastospores harvested from 8-(exponential phase) or 48-h (stationary phase) cultures were incubated with 60 x 10(-3) M [1- C-13]glucose with or without 10(-4) M amphotericin B (AmB). The utiliz ation of [1-C-13]glucose was monitored by in vivo C-13 NMR under anaer obiosis. With exponential phase cells, in the presence of AmB, the con sumption of glucose and the production of ethanol, trehalose, and glyc erol continuously decreased with time, and after 25 min, the metabolis m was blocked. On stationary phase cells AmB had almost no effect on g lucose metabolism. Comparison with previous experiments evidenced that AmB induced first K+ leakage, then acidification, and finally a stop of the metabolism. In parallel, in vitro C-13 NMR spectra were perform ed on supernatants and cell-free extracts of yeast suspension incubate d under the same conditions. For both exponential and stationary phase cells, AmB induced an increase in the membrane permeability to glycer ol; no change was observed for the other metabolites.