Development of specific experimental systems for flavinogenesis using non-growing cell of Eremothecium ashbyii.

Abstract

Experimental systems using non-growing cell of Eremothecium ashbyii to elucidate the mechanism of flavinogenesis were established in this paper.1. It was found that vacuum infiltration of purines for 2, 3 and 5 min and moderate shaking of non-growing cell brought about a good reproducibility of the stimulatory effects on flavinogenesis by purines and furthermore, a higher flavinogenesis.2. The addition of an inhibitor of protein synthesis, chloramphenicol, to the basal medium at the concentration of 6mM after 1 day of cultivation resulted in a 45.1% inhibition of the growth measured after 2 days of cultivation and a 65.1% inhibition of riboflavin production measured after 4 days of cultivation. On the other hand, the addition of an inhibitor of purine de novo synthesis, sulfanilamide at 4mM resulted in a 24.3% inhibition of the growth after 2 days and a 44.1% inhibition of riboflavin formation after 4 days respectively.3. The addition of these drugs and another inhibitor of protein synthesis, cycloheximide to the non-growing cell medium brought about little effects on flavinogenesis and only cycloheximide showed a 25% inhibition of riboflavin production at 7mM.4. It was elucidated from above results that non-growing cell under such the special conditions shows little or no synthesis of protein and purine derivatives but there occurs flavinogenesis to a fair extent.5. It was found that xanthine is the most flavinogenic purine among various purines during these experiments.