In situ separation of lactic acid from fermentation broth using ion exchange resins

Lactic acid fermentation is an end product inhibited reaction. In situ separation of lactic acid from fermentation broth using ion exchange resins was investigated and compared with conventional fermentation system. Amberlite resin (IRA-400, Cl⁻) was used to separate lactic acid from fermentation broth and pH was controlled online with an automatic pH controller. The effect of process variables on lactic acid production by Lactobacillus casei in whey permeate was studied. The maximum productivity was obtained at pH = 6.1, T = 37 °C and impeller speed = 200 rpm. The maximum concentration of lactic acid at optimum condition was found to be 37.4 g/L after 38 h of fermentation using in situ separation system. The productivity of in situ separation system was five times increased in comparison with conventional system.