Abstract
The effects of riboflavin on the formation of kojic acid from dihydroxyacetone, glycerol, fructose, glucose, galactose and disaccharides by the riboflavin-less mutant of Aspergillus oryzae were investigated, and it was found that riboflavin accelerated significantly the formation of kojic acid. In the presence of riboflavin and maltose, kojic acid was formed from dihydroxyacetone without any lag period, and large amounts of riboflavinylglucoside and of riboflavinyltrioside were again produced at the early stages of fermentation. But when the amount of riboflavin diphosphate, which was produced in the later stages of fermentation, was found to be superior to that of riboflavinylglucoside, the velocity of kojic acid formation became diminishing. Therefore, the sugar compound of riboflavin was suggested to play an important role on the biosynthesis of kojic acid.
