From residues to clove: Harnessing novel phenolic acid decarboxylase for 4-Vinyl guaiacol production in industrial Yeast

Abstract

Growing demand for sustainable alternatives to petroleum-derived aromatic compounds highlights lignocellulosic biomass as a potentially valuable resource. Although cellulose and hemicellulose, the major components of lignocellulose, are widely used in biofuel and chemical production, lignin, another predominant plant biomass component, remains underutilized. Chemical pretreatment methods for lignocellulose, such as mild alkali, can release cross-linked hydroxycinnamic acids such as ferulic acid, a precursor to various aroma compounds such as 4-vinyl guaiacol (4-VG), which has a clove-like aroma. To improve 4-VG production, an industrial strain of Saccharomyces cerevisiae Ethanol Red™ was engineered to express a novel phenolic acid decarboxylase (PDC) gene from Rhodosporidium fluviale LM-2, Rf_PDC_B. Mutant strain expressing Rf_PDC_B achieved 4-VG levels comparable to those reported in the literature after 48 h of fermentation using maize pericarp hydrolysate as the substrate, demonstrating efficient biotransformation of ferulic acid from lignocellulosic hydrolysates into 4-VG. In summary, a transformed cell line was created for the direct biocatalytic production of aromatic compounds from lignocellulosic hydrolysates. This study contributes to the development of novel technologies related to the sustainable production of high-value compounds derived from lignin.