Integrated omics-based analysis reveals the role of ferulic acid activating a co-production of 4-vinyl guaiacol and fumaric acid by Rhizopus oryzae.

The efficient valorization of lignocellulose-derived phenolics remains a major challenge in sustainable biomanufacturing. Here, an integrated omics approach was employed to elucidate how ferulic acid (FA) activates the co-production of 4-vinyl guaiacol (4-VG) and fumaric acid by Rhizopus oryzae. Co-supplementation of FA with glucose significantly enhanced metabolic performance, increasing fumaric acid yield by 16.9% and inducing simultaneous 4-VG synthesis. Metabolomic profiling revealed that FA reprograms cellular metabolism by reinforcing the tricarboxylic acid cycle and redox pathways while redirecting carbon flux from amino acid biosynthesis toward C4-dicarboxylic acid and fatty acid metabolism. Proteomic analysis confirmed a dual regulatory strategy: up-regulation of enzymes involved in energy production, peroxisomal function, and lipid metabolism, accompanied by down-regulation of amino acid and ribosomal proteins. Interpretation of combined omics datasets suggests that FA may function both as a substrate and as a signaling-like metabolic regulator, driving a production-optimized, redox-balanced state. This systemic reconfiguration maximizes energy and precursor efficiency for dual-product formation. The study provides mechanistic insight into FA-induced metabolic adaptation, offering a rational basis for metabolic engineering and process intensification in lignocellulosic biorefineries.