Production of lactic acid by continuous electrodialysis fermentation with a glucose concentration controller

In this study, the system of electrodialysis fermentation (EDF) was improved by a glucose concentration controller (GC controller) which could control glucose concentration stable and low in fermentation broth. Under the control of the GC controller, there were little inhibitory effects of the end product and substrate on bacteria so as to result in high activity of bacteria and, further, in high productivity of lactic acid. Moreover, the low glucose concentration in the fermentation broth brought about little glucose leakage to the recovery solution and hence high yield of lactic acid. Compared with the EDFs carried out in the previous studies, the continuous EDF with a glucose concentration controller (CEDF with GC controller) was higher in productivity, yield and conversion ratio of lactic acid, indicating that it was a system more efficient to produce lactic acid. (c) 2005 Elsevier B.V. All rights reserved.