Abstract
TPD (thiamine propyldisulfide) in the broth containing a mixture of amino acids instead of casamino acids, was shown to have better growth-response on L. fermenti than thiamine-HCl. When TPD or thiamine was preincubated with each amino acid of the broth and cysteine for 6 hours and then rests of amino acids and other components were added, TPD was proved to have better growth-responsse on L. fermenti than thiamine only in preincubation with arginine, glutamic acid, histidine, phenylalanine or proline. Among components other than amino acids, glucose, xylose, riboflavin, nicotinic acid or pantothenate in preincubation with TPD and cysteine was shown to be more effective than thiamine-HCl for the growth of L. fermenti. TPD with cysteine alone in preicubation, however, showed to have equal growth-response to thiamine-HCl. Preincubation of TPD, cysteine and some components of the broth is necessary for better growth-response of lactobacilli which might have accelerated by reduced thiamine by cysteine and some components in the broth.
