Thiamine Sparing Action of Ascorbic Acid on Lactobacillus Fermenti 36. ∗

Abstract

Summary

1. Ascorbic acid has been found to have thiamine sparing action on the growth of L. jermenti 36. The addition of both ascorbic acid and thiamine gives a greater growth response than either one when added alone. 2. Addition of pyrithiamine inhibits the utilization of ascorbic acid for growth of L. jermenti 36 in a thiamine-free medium. This result shows that ascorbic acid may function in part by stimulating the synthesis of thiamine. 3. Addition of iodoacetate, 2,4-dinitrophenol or sodium fluoride to the thiamine assay medium containing either thiamine or ascorbic acid shows the difference in inhibition of growth of L. jermenti 36. These results indicate that ascorbic acid must also function in a different metabolic pathway as compared to thiamine in carbohydrate metabolism. 4. It was found that L. jermenti 36 was able to synthesize thiamine when ascorbic acid was present. With the presence of both ascorbic acid and thiamine in the assay medium, the cell was found to contain more thiamine than the cell grown in thiamine medium alone.