Comparative Transcriptomics Reveals the Molecular Basis for Inducer-Dependent Efficiency in Gastrodin Propionylation by Aspergillus oryzae Whole-Cell Biocatalyst

Propionylated derivatives of gastrodin are valuable due to their enhanced lipophilicity and bioavailability. This study investigated the molecular basis for the differential catalytic efficiency of <i>Aspergillus oryzae</i> whole cells in gastrodin propionylation. A high conversion rate of 96.84% was achieved with soybean oil induction, compared to only 8.23% under glucose induction. Comparative transcriptomic analysis identified 20,342 differentially expressed genes (DEGs), which were significantly enriched in lipid metabolism and signal transduction pathways. From 26 upregulated lipase-related DEGs, a candidate triacylglycerol lipase gene (CL24.Contig40_All) was prioritized. Homology modeling and molecular docking supported its potential role by demonstrating that the encoded enzyme possesses a typical α/β hydrolase fold with a catalytic triad and favorable binding with both gastrodin and vinyl propionate. These findings indicate that soybean oil may enhance lipase expression by activating lipid metabolic and phosphatidylinositol signaling pathways, providing crucial transcriptional-level insights and genetic targets for the rational design of efficient whole-cell biocatalysts.