抄録
Thiamine, when added to the thiamine-free Atkin's broth in increasing concentrations, first stimulated the growth of Saccharomyces carlsbergensis 4228 slightly better than the control, but in higher concentrations than 10^<-6>M, caused a marked growth-inhibition which was counteracted by pyridoxine. Modified thiamine compounds in place of thiamine, were tried for their effects on the growth of Saccharomyces. (a) Thiamine disulfide, thiamine propyldisulfide and other asymmetric disulfides of thiamine showed similar patterns of stimulation and inhibition on the increase of concentrations. Only O-benzoylthiamine disulfide exhibited no inhibition but growth-stimulation in higher concentrations. (b) Among the acyl derivatives of thiamine, S-benzoylthiamine was the most powerful inhibitor. The effects of others were shown according to the following inequality : Thiamine>S-benzoylthiamine>O-benzoylthiamine>S-benzoylthiamine phosphate. O, S-diacetylthiamine exhibited no inhibition. O, S-dibenzoylthiamine (DBT) stimulated the growth in high concentration. (c) Both alkoxycarbonylthiamines and thioether-type thiamines showed no inhibition. (d) Thiamine monophosphate and diphosphate exhibited similar inhibition pattern to thiamine, dihydrothiamine, one tenth the inhibition of thiamine, but thiothiamine stimulated the growth. The inhibition caused by modified thiamine compounds was counteracted by pyridoxine. Correlations between growth-stimulation to Lactobacillus fermenti and growth-inhibition to Saccharomyces carlsbergensis by the compounds were observed. Noninhibitory DBT distributed much less than thiamine and was present as such in the cells. Hence the inhibitory effect of modified thiamine compounds seems to depend upon whether they are converted to thiamine by Saccharomyces carlsbergensis.
