Abstract
The respiration of baker's yeast was found to be stimulated by the addition of thiamine and inhibited with sorbate. However, during the studies on the sorbate inhibition concerned with the yeast respiration using pyruvate as substrate, the authors found that the coexistence of thiamine and sorbate has a significant inhibitory effect on the respiration. Butyrylthiamine disulfide or thiamine diphosphate in place of thiamine show the same effect, but none of benzoate, salicylate, dehydroacetate or propionate in place of sorbate show the effect. This characteristic effect was also observed with the substrate, glucose or acetate. The inhibitory effect was also found at the growth of the microorganism under the condition of shaking culture, but, at stationary condition this effect was no longer observed. The fact that this effect is hardly observed in the cells containing high level of CoA would give us an available suggestion for the inhibition mechanism.
