Continous production of free gluconic acid by Gluconobacter suboxydans IFO 3290 immobilized by adsorption on ceramic honeycomb monolith: effect of reactor configuration on further oxidation of gluconic acid to keto-gluconic acid

Summary Gluconobacter suboxydans IFO 3290 was immobilized by adsorption on ceramic honeycomb monolith, and continuous production of free gluconic acid from 100 g/l glucose was carried out in one- and three-stage monolith reactors. Further oxidation of gluconic acid to keto-gluconic acid by the immobilized cells has been found to be more suppressed in the three-stage monolith reactor. This finding can be explained by the fact that, with the three-stage reactor, the opportunity to oxidize gluconic acid further was decreased because the residence time of the reaction mixture at glucose conversion above the threshold value was shorter.