Enzymes are natural catalysts which are gaining momentum as more selective alternatives to traditional chemical catalysts. However, enzymes are not adapted to the non-natural conditions to which they may be exposed during reactions (i.e. extreme pH or temperature, presence of organic co-solvents). Hence, they suffer from low stability which impacts their sustainability and cost-efficiency. To tackle this issue, we have focused on two main strategies: enzyme immobilization and flow chemistry. Enzymes can be immobilized by simple attachment to particles, becoming a more resistant heterogeneous biocatalyst and enabling its reusability. Recently, we have developed new immobilization strategies as well as novel materials from renewable sources to reduce the waste and costs of this technique. Once the enzyme is immobilized, we integrate the biocatalyst into a continuous-flow reactor for process intensification. By using flow biocatalysis, we have produced antiviral and anticancer drugs as well as fragrances in shorter times while obtaining higher product yields compared to batch reactions.