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Lactic Acid Fermentation from Tapioca Starch by Lactobacillus casei TISTR 453 using Simultaneous Saccharifiation and Fermentation Process

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Chaowaree Adthalungron, Nidarat Saechua and Kasara Doungkaew

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-Lactic acid and its derivatives have wide applications in various industries. One of the most interesting applications of lactic acid is to serve as a monomer for polylactide synthesis. In the current research, lactic acid production from tapioca starch by lactic acid bacterium, Lactobacillus casei TISTR 453, was studied using a simultaneous saccharification and fermentation process. We focused on investigating optimum temperature and medium compositions. Tapioca starch was supplied at 150 g/L and starch hydrolysis was initiated by the addition of 0.10 % (v/starch wt.) - amylase. Subsequently, liquefied starch was used to prepare a fermentation medium (modified MRS formula). Afterwards, 0.10% (v/starch wt.) glucoamylase as well as lactic acid starter at 10 6 CFU/ml were simultaneously induced and lactic acid fermentation was allowed for 72 h. The results revealed that 40 C was an optimum temperature. For the optimization of glucoamylase and medium compositions when response surface methodology (RSM) with centrl composite design (CCD) was employed, the results suggested that 0.10% (v/starch wt.) glucoamylase, 87.5 g/L calcium carbonate, and 10.0 g/L yeast extract were optimal. The model generated from RSM showed a predicted lactic acid concentration at 131.50 g/L when fermentation was conducted using Lb. casei TISTR 453 with the optimized medium and incubated at 40 C for 48 h. Eventually, the results were validated using the optimized medium resulting in 130 g/L lactic acid, which corresponds to 0.87 g lactic acid/g starch.

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lactic acid, tapioca starch, simultaneous saccharification and fermentation