Kinetic of lactic acid production from sugarcane juice using Lactobacillus plantarum NCIM 2912

Abstract

ABSTRACTKinetics of batch fermentation of sugarcane juice for lactic acid production by Lactobacillus plantarum NCIM 2912 under anaerobic conditions has been analyzed. Lactic acid fermentation with this bacterium is found to be homolactic. Kinetics of cell growth and multiplication fits reasonably into Monod's kinetic model, and the Luedeking–Piret equation has been found to reliably predict kinetics of lactic acid production. The kinetic parameters have been determined on the basis of experimental data using a program developed in Microsoft Excel and matlab. The value of the key kinetic constants estimated is the maximum specific growth rate (μmax), 0.92/h; substrate limitation constant (Ks), 44.1 g/L; growth‐associated constant (α), 10.08 g/g; and nongrowth‐associated constant (β), 0.92 g/g h for lactic acid production. Maximum lactic acid concentration and productivity were found to be 89.5 g/L and 1.243 g/L h, respectively. Kinetic analysis thus revealed that lactic acid production is predominantly growth associated. Effect of substrate inhibition has been observed to be relatively small. Stoichiometric parameters have been estimated to be the maximum product yield coefficient YPS, 0.83 g, lactic acid/g sucrose and average cell mass yield coefficient Yxs, 0.47. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.