Abstract
Eremothecium ashbyii was cultivated on a peptone medium by tank culture and Increase and decrease in weight of the mycelium were investigated on the samples collected at various stages of the culture. At the same time, amount of riboflavin and FAD in the mycelium and the broth were determined. As a result it was found that the amount of riboflavin in mycelium showed a maximum during 50∼90 hours after the start of the culture, but the maximum of FAD occurred several ten hours later than the former. On the other hand, riboflavin in the broth suddenly increased in weight at a comparatively early stage of the culture and showed no sign of decreasing even after the mycelium began autolysis, while FAD in the broth gradually increased in weight after the mycelium began autolysis, though the total amount was very small.