Biocatalytic synthesis of vanillin from biomass-derived compounds: A review

Vanillin is an important flavoring compound commonly obtained through natural extraction or by chemical synthesis. However, the supply of naturally extracted vanillin is insufficient to meet the growing demand, and the utilization of chemically synthesized vanillin in various industries such as food and perfume is constrained due to growing health and environmental concerns. In light of this situation, biocatalysis offers promising perspectives to tackle these emerging challenges by employing either isolated enzymes or whole cells as biocatalysts. Recently, the biocatalytic synthesis of vanillin using biomass-derived compounds as precursors has been attracting increasing attention. This review aims to discuss recent advances in the synthesis of vanillin from various renewable biomass-based substrates through biocatalytic processes. A variety of recently discovered enzymes or recombinant cells used as biocatalysts for the production of vanillin are summarized. In addition, the protein engineering and the different strategies of constructing enzymatic cascade reactions applied to improve the bioconversion efficiency in vanillin production are also discussed.