1971 Volume 66 Issue 4 Pages 404-410
The formation of kynurenic acid from yeast was investigated. Kynurenic acid was formed from yeast from tryptophan and kynurenine but was not formed from other amino acids contained in sake. The velocity of kynurenic acid formation from kynurenine was faster than tryptophan.
The activity of kynurenic acid formation from tryptophan was high at the log phase of yeast growth. This fact was corresponded with the case of sake moromi mash.
Kynurenic acid formation from tryptophan was inhibited by histidine, arginine, threonine, serine, alanine, cysteine, p-CMB, monoiodoacetate, cyanide, azide and semicarbazide, but was accelerated by glycine, β-alanine, EDTA, sodium sulfite, ascorbic acid, nicotinamide and Ca-pantothenate. Elevated amounts of kynurenic acid were excreted in vitamin B6 deficient or less yeasts.
Acceleration of kynurenic acid formation by nicotinamide accounted for the conversion of tryptophol formation into kynurenic acid formation. The amounts of kynurenic acid formed by various yeasts correlated closely to the contents of nicotinic acid in yeasts.
