Abstract
In order to elucidate the mechanism of growth-inhibition of Saccharomyces carlsbergensis 4228 by thiamine, effects of thiamine on growth and vitamin B_6 content of the yeast cells growing in the media containing alanine, phenylalanine, or glutamic acid and methionine as the nitrogen source were investigated. The transient increase of the vitamin B_6 content at the initial growth phase was depressed by addition of thiamine to the medium in all cases, but at the peak stages vitamin B_6 content of the yeast in the medium containing alanine was much higher than those in the medium containing phenylalanine or glutamate and methionine. The amino acids detected in these media after growth of the yeast were not markedly different from those detected in the media with thiamine, but the consumption rate in the Atkin's medium with thiamine was found to be higher in alanine, aspartic acid, glutamic acid, and arginine, and to be lower in threonine, glycine, valine, proline, and serine than that in the medium without thiamine.
