Abstract
L. fermenti 36,when incubated with thiamine or TPD (thiamine propyldisulfide) in MaciasR broth containing cysteine, showed better growth-response to TPD than to thiamine at suboptimal concentrations. Thiamine contents of cells of lactobacilli were very low and getting higher on addition of surplus thiamine, but the thiamine added was found chiefly in the broth ; no significant difference of thiamine contents of cells between TPD and thiamine was found in any stage of the growth. Thiamine can penetrate into cells only when lactobacilli were preincubated in thiamine-deficient broth. Although thiamine in cells as its diphosphate, was proved to be decisive of the growth, TPD in the broth had no effect to elevate thiamine content of cells higher than that of cells in the broth containing equivalent thiamine. Better growth response to TPD shall be elucidated in the papers published later.
