No abstract

The uptake of tartrate by P. clcnrlesii has been studied for cult~~res that were either aerated by shaking or were kept stationary. Stationary cultures were permeable to tartrate when high concentrations of NH4+ (above 36 mM) and glucose (278 mM) were present. Manganous ion (10-5 M ) was required for the uptake of tartrate by stationary cultures containing high concentrations of NH4+. Both stationary and shake cultures were able to remove tartrate from the medium when the glucose concentration was reduced below 278 mM; the process was then no longer dependent upon the presence of MnZ1-. The influence of changes in the concentrations of glucose and NH4+ was not related to the biochemical events of spore germination.

The utilization of L(+)-tartrate in Aspergillus flavus is constitutive. The use of tartrate by these cells is inhibited by the metabolic poisons 2,4-dinitrophenol and sodium azide. Glucose, mannose, and sucrose at high extracellular concentrations prevent the utilization of L(+)-tartrate by the young mycelium. Ammonium ion increases the inhibition due to glucose, while the addition of ferric ions to the external medium prevents the glucose-induced inhibition of tartrate utilization.