Thiamine Limited Steady State Growth of the Yeast Cryptococcus albidus

SUMMARY The concentration/growth rate relationship of thiamine-requiring Cryptococcus albidus was examined. Data suggest a diffusion-limited mechanism characterized by an apparent Michaelis constant for growth of 4·7 × 10–13 m. This relationship was obtained from continuous culture at steady state and tested by a non-steady state procedure and in batch growth. It was concluded that most natural water systems have sufficient thiamine to support some thiamine-requiring micro-organisms at above rate limiting concentrations.