Production of gluconic acid with immobilized glucose oxidase in airlift reactors

An external loop airlift bubble column, an internal loop airlift and a normal bubble column were employed as promising bioreactors to carry out the immobilized glucose oxidase catalyzed oxidation of glucose with air to produce gluconic acid as a model of immobilized enzyme reactions. We used the calcium alginate gel beads entrapping glucose oxidase as well as fine palladium particles to decompose hydrogen peroxide formed together with gluconic acid. Since hydrogen peroxide deactivates glucose oxidase, it is important to control accumulation of hydrogen peroxide in the gel beads. Optimal reactor design and operating conditions were searched for in relation to its accumulation based on the reaction kinetics and reactor characteristics. (C) 1997 Elsevier Science Ltd.