Use of electrodialysis technique for the separation of lactobionic acid produced by Zymomonas mobilis

The separation of lactobionic acid (LBA), a product of a biotechnological process catalyzed by the enzymes glucose-fructose oxidoreductase and glucono-δ-lactonase of the bacteria Zymomonas mobilis, was studied using ion selective membranes in electrodialysis (ED). The recovery of LBA, present in a solution with a concentration of 20 g L-1, was 38.7% in 250 min of testing for an electrical potential difference of 15 V. When compared with a solution containing all the components present in the bioconversion (lactose, fructose, and sorbitol), the recovery was inhibited by the presence of non-ionic substances and the LBA recovery efficiency decreased to 16.2%. The same behavior was observed when a Z. mobilis bioconversion medium was used, with a recovery of 14%. Despite the low recovery efficiency the high specificity in relation to the other bioconversion components makes this process suited for LBA production.