Abstract
A continuous packed bed reactor for NADH-dependent biocatalysis using enzymes co-immobilized on a simple carbon support was optimized to 100% conversion in a residence time of 30 min. Conversion of pyruvate to lactate was achieved by co-immobilized lactate dehydrogenase and formate dehydrogenase, providing in situ cofactor recycling. Other metrics were also considered as optimization targets, such as low E factors between 2.5-11 and space-time yields of up to 22.9 g L(-1) h(-1). The long-term stability of the biocatalytic reactor was also demonstrated, with full conversion maintained over more than 30 h of continuous operation.