Enhancing Mycoprotein Yield: Metabolic Modulation of Chitin Synthase in <i>Fusarium venenatum</i>

<i>Fusarium venenatum</i> is being extensively utilized for microbial protein production. However, its high dietary fiber content results in substantial carbon loss. Inhibition of chitin biosynthesis presents a promising strategy to improve the mycoprotein yield. Through transcriptomic and bioinformatics analyses, chitin synthase gene <i>FvChs3</i> was identified as crucial for chitin synthesis in <i>F. venenatum</i>. Knockout of the <i>FvChs3</i> gene resulted in mycelial expansion and a 26% reduction in the chitin content of strain Δ<i>FvChs3</i>. Ethanol production from fermentation decreased by 47%, while the carbon conversion efficiency and protein conversion increased by 16% and 36%, respectively. Transcriptomic analysis revealed an upregulation of nitrogen metabolism in Δ<i>FvChs3</i>, while genes related to the glycolysis pathway for ethanol synthesis were downregulated. Further knockout of pyruvate decarboxylase gene <i><b>FvPDC6</b></i> in Δ<i>FvChs3</i> accelerated growth, leading to improvements in carbon and protein conversion of 29% and 40%, respectively. This research lays the foundation for enhancing fungal protein production.