Abstract—Experimental investigations has been carried to obtain high productivity of lactic acid by Lactobacillus (Lb.) casei MTCC 1423 cells immobilized in sodium alginate which is characterized by long term stability and high cell densities maintained in fermentation media. Influence of sugar concentration and dilution rate on lactic acid production in a continuous two stage process consists of constant stirred tank reactor and a packed bed column by immobilized Lb. casei cells has been investigated. After the 1st stage reactor (CSTR), with the dilution rate enhancement (0.05 - 0.3h^-1), lactic acid production had decreased from 106±3 to 65.36±3 g/L, from 68±2.6 to 43.64±2.5 g/L and 36.34±2.2 to 27.12±2.0 g/L at initial molasses sugar concentration of 175, 100 and 50 gm/L respectively. During 2nd stage, at the low dilution rate (=0.05 h^-1), an enhancement of approximately 10±2%, 8±1.5% & 5±1.5% in lactic acid production was observed at high initial sugar content of 175 g/L,100 g/L & 50 g/L respectively after 1st stage. Negligible/very low additional lactic acid production/sugar consumption was observed in the 2nd stage reactor (plug flow reactor) for dilution rate ≥0.1 h^-1.
 

Index Terms—constant stirred reactor, packed bed reactor, immobilized cells, Lactobacillus casei, dilution rate, sugar concentration

Cite: Avinash Thakur, Paramjit S. Panesar, and Manohar S. Saini, "Continuous Production of Lactic Acid in a Two Stage Process Using Immobilized Lactobacillus casei MTCC 1423 Cells," International Journal of Food Engineering, Vol. 4, No. 3, pp. 216-222, September 2018. doi: 10.18178/ijfe.4.3.216-222