Integration of a multi-enzyme system with a liquid membrane in Taylor flow regime for the production and in situ recovery of gluconic acid from cellulose

Since the demand for gluconic acid has increased during the last years, alternative processes to minimize its production costs associated to raw material and separation are being developed. In this study, a hybrid process consisting of gluconic acid production by a multi-enzyme system with an in situ gluconic acid recovery by a liquid membrane in Taylor flow is analyzed. Gluconic acid production was carried out from microcrystalline cellulose, using the following enzymes: cellulase, β-glucosidase, glucose oxidase and catalase. The liquid membrane in Taylor flow system was constituted by a membrane phase of trioctylamine/1-dodecanol, a receiving phase of sodium carbonate and the donor phase was the multi-enzyme broth. Enzymes did not show inhibitory effects by the organic phase of the liquid membrane. pH control by the liquid membrane in Taylor flow, as well as low ionic strength in the multi-enzyme broth, enhances gluconic acid production. Gluconic acid productivity and yield in the hybrid system were 1.6- and 1.7-fold higher than the values obtained using the multi-enzyme system with sodium acetate buffer, respectively. In situ gluconic acid recovery by the liquid membrane in Taylor flow system is a promising approach to enhance gluconic acid production by the multi-enzyme system.