Continuous lactic acid fermentation with concentrated product recovery by ultrafiltration and electrodialysis

Abstract

Lactose of sweet whey permeate was converted into sodium lactate byLactobacillus helveticus. To increase the, productivity of the lactic acid fermentation and to reduce the amounts of effluents, the bioreactor was coupled with an ultrafiltration module and an electrodialysis unit. Without the electrodialyzer, with total cell recycling and at a dilution rate of 0.88 h⁻¹, a cellular concentration of 64 gl⁻¹ and a productivity of 22 gl⁻¹ h⁻¹ were obtained. When the electrodialysis unit is coupled, the outlet concentration of lactate was stabilized at 85±5 gl⁻¹.