3. Natural" vanillin production by filamentous fungi

3.1 Obtaining the natural precursor of vanillin: ferulic acid

Ferulic acid is an abundant compound in plant cell walls, where it is generally esterified to polysaccharides via oses such as arabinose or galactose. It can also be found in the aromatic fraction of inexpensive agricultural by-products available in large quantities. Two agricultural co-products from existing technologies, corn bran (residues from the starch industry) and beet pulp (residues from the sugar industry), were chosen as sources of precursors with aromatic structure, due to their low cost, availability and high phenolic...