Continuous Electrodialysis Fermentation of Lactic Acid by Lactobacillus rhamnosus

Abstract

In this study, electrodialysis fermentation (EDF) was carried out by means of continuous EDF with feed medium. To keep the volume of fermentation broth constant, feed medium was controlled by a level controller. When glucose concentration in feed medium was 175 g/L, the continuous EDF lasted for above 350 h and was stable for above 200 h. Compared with the other EDFs, the continuous EDF with a level controller had the highest productivity and the longest fermentation term. Hence, the amount of lactic acid produced was about 19.5 times greater than that of the conventional batch EDF. The glucose was, however, insufficient in fermentation broth from around 100 h with the result that the activity of bacteria decreased after 200 h, which caused the excess of glucose in fermentation broth after 200 h.