Continuous synthesis of l-malic acid using whole-cell microreactor

► Saccharomyces cerevisiae cells were immobilized within a plastic microchannel. ► A whole-cell microbioreactor was used for a continuous biotransformation. ► Several process parameters were evaluated regarding process productivity. ► The use of a microbioreactor enabled fast and low-cost process optimization. ► A volumetric productivity of 646 mM/day of l-malic acid was achieved.