Quantitative Studies on Glycolytic Enzymes in Lactobacillus plantarum

The intracellular activity of glyceraldehyde-3-phosphate dehydrogenase was estimated. The dehydrogenase was purified about 70-fold by ammonium sulfate fractionation and DEAE cellulose chromatography. Basal properties of the purified enzyme were examined. From the activity of the enzyme in the sonicate, the intracellular activity was calculated by correcting the value for the intracellular conditions which were known previously. The intracellular activity of the dehydrogenase was found to be nearly equal to that of the lactate-forming activity from glucose in original washed cells, showing a significant participation of the dehydrogenase in the metabolic pathway of lactic acid fermentation in this organism.