Ability of S-Methyl-L-cysteine to Annul the Inhibition of Yeast Growth by L-Ethionine and by S-Ethyl-L-cysteine

SUMMARY: The inhibition of growth of a brewer's yeast and four other yeasts by L-ethionine, and the annulment of the inhibition by L-methionine were examined. S-Methyl-L-cysteine, DL-methionine sulphoxide and DL-α-amino-n-butyric acid were also able to decrease the growth inhibition. At a fivefold molar concentration, S-methyl-cysteine annulled completely the effect of ethionine on the brewer's yeast. S-Ethyl-L-cysteine was ineffective and in certain conditions it acted as a growth inhibitor; this inhibition was annulled by methionine and by S-methylcysteine.