KKU Research Journal
ISSN 0859-3957

շ 19 Ѻ 6+ January - February 2015

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

Chaowaree Adthalungrong1,*, Nidarat Saechua1 and Kasara Doungkaew1

 

Department of Microbiology, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand

*Correspondent author: rchaowaree@yahoo.com

 

Abstract

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.

 

Keywords : lactic acid, tapioca starch, simultaneous saccharification and fermentation



 

Division of Research Administration.
Building2, 2nd Floor,Office of the President.
Khon Kaen University
Tel. 043-009700 ext. 42128
E-mail: kkurj@kku.ac.th