Abstract
The cell free extracts from L. fermenti was proved to metabolize ribose-5-phosphate quickly on incubation and no formation of hexose was demonstrated. Addition of thiamine diphosphate accelerated the degradation of ribose-5-phosphate ; this suggested that lactobacilli has the enzyme-system connected with thiamine diphosphate as coenzyme in the hexcse phosphate pathway. L. fermenti, preincubated with TPD (thiamine propyldisulfide), cysteine and other effective components of the broth, was demonstrated to contain the strongest enzymatic activity of metabolizing ribose-5-phosphate per mg protein of its cell free extracts in comparison with lactobacilli preincubated with or without thiamine in control experiments. Addition of TDP to the cell free extracts in all the cases was effective to accelerate the reaction, especially for lactobacilli preincubated with TPD. Lactobacilli, preincubated with TPD, cysteine and other effective components of the broth, was proved to be superior to those, preincubated with thiamine in its growth on incubation of the washed cells with MaciasR broth containing no thiamine.
