In contrast to the application of soluble enzymes in industry, immobilized enzymes often offer advantages in view of stability, volume specific biocatalyst loading, recyclability as well as simplified downstream processing. In this tutorial review the focus is set on the evaluation of immobilized enzymes in respect to mass transport limitations, immobilization yield and stability, to enable industrial applications.

The bacterial decarboxylase (AMDase) catalyzes the enantioselective decarboxylation of prochiral arylmalonates with high enantioselectivity. Although this reaction would provide a highly sustainable synthesis of active pharmaceutical compounds such as flurbiprofen or naproxen, competing spontaneous decarboxylation has so far prevented the catalytic application of AMDase. Here, we report on reaction engineering and an alternate protection group strategy for the synthesis of these compounds that successfully suppresses the side reaction and provides pure arylmalonic acids for subsequent enzymatic conversion. Protein engineering increased the activity of the synthesis of the (S)‐ and (R)‐enantiomers of flurbiprofen. These results demonstrated the importance of synergistic effects in the optimization of this decarboxylase. The asymmetric synthesis of both enantiomers in high optical purity (>99 %) and yield (>90 %) can be easily integrated into existing industrial syntheses of flurbiprofen, thus providing a sustainable method for the production of this important pharmaceutical ingredient.

To overcome limitations due to the high viscosity in the solvent free esterification of polyglycerol-3 and related polyols, such as poly(ethylene glycol)s, an alternative reactor concept was developed. The new reactor comprises a bubble column that prevents mechanical erosion of Novozym 435 (lipase B from Candida antarctica) found by mechanical stirring of the mixture. That way polyglycerol-3 laurate was synthesized at a space time yield (sty) of 3042 g/L/d and PEG-55-propylene glycol dioleate at a sty of 738 g/L/d. To proof the broad application range of this system, low-viscosity myristyl myristate was synthesized at a sty of 6731 g/L/d, thus outperforming conventional methods such as stirred tank or fixed bed. The newly developed reactor concept is universally applicable to esterification reactions and can be advantageously applied in the synthesis of a broad range of high quality surfactants.

The immobilization of an endoglucanase, benzoylformate decarboxylase (BFD) from Pseudomonas putida, as well as of lipase B from Candida antarctica (CALB) onto the carrier supports Sepabeads EC-EP, Sepabeads EC-EA, and Sepabeads EC-BU was accomplished. It is shown that via these immobilized biocatalysts the synthesis of both fine and bulk chemicals is possible. This is illustrated by the syntheses of polyglycerol esters and (S)-hydroxy phenyl propanone. The benefit of immobilization is illustrated by repetitive use in a bubble column reactor as well as in a stirred tank reactor. High stability of two biocatalysts was achieved and reusability up to eight times was demonstrated. The comparison of CALB immobilized on Sepabeads EC-EP to Novozym 435 shows similar activity.