Process considerations for use of galactose oxidase as an industrial biocatalyst

In nature galactose oxidase (GOase, EC.1.1.3.9) catalyses the oxidation of the C6 hydroxyl group of D-galactose to the corresponding aldehyde, while reducing molecular oxygen to hydrogen peroxide. In recent years a great effort has been made to broaden the substrate scope, enabling GOase to oxidize C6-OH of glucose and fructose, as well as secondary alcohols to ketones. The widened substrate scope of GOase opens up many important industrial applications, such as synthesis of industrially relevant compounds containing aldehydes and ketones (e.g. the oxidation of 5-hydroxymethylfurfural to diformylfuran), deracemization of secondary alcohols, and modification of a wide range of naturally occurring polysaccharides [1,2]. Despite these promising characteristics of GOase, application at industrial scale has not been achieved so far. This can in part be ascribed to the process challenges experienced when performing oxidative biocatalysis at a large scale