Influence of Sucrose, Glucose, Stevia Leaf and Stevioside on the Growth and Lactic Acid Production by Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus casei

Probiotics are beneficial bacteria that exert beneficial health effects on the host. These bacteria produce lactic acid as a product of fermentation. The aim of this study was to optimize growth and production of lactic acid by three strains of probiotic bacteria at different concentrations of sucrose, glucose, stevia leaf and stevioside. These three strains were Lactobacillus casei, Lactobacillus brevis and Lactobacillus plantarum. Lactic acid production and bacterial growth were, respectively, estimated by use of gas chromatography and colony-forming units (CFU) assay. The highest bacterial growth and lactic acid production in these three strains were obtained by high concentration of sucrose. Among these three bacteria, Lact. casei and Lact. brevis can produce more lactic acid compared to Lact. plantarum. All strains could produce lactic acid in the presence of sucrose, glucose and stevia leaf extract in a dose dependent manner. The effect of stevioside on lactic acid production in these strains at high and low concentrations was almost same. In conclusion, data indicate that sucrose is the best carbon source for lactic acid production and bacterial growth. Stevioside and stevia leaf also have a good potential to increase lactic acid production in these three strains.