Genetic approach to discover a valuable gene for enhanced nutritional value in the edible filamentous fungus Fusarium venenatum

Mycoprotein is critical in a dietary shift toward a more sustainable food system. However, the strain improvement for enhancing mycoprotein via genetic manipulation is lacking. Here, we investigated the functions of proteins related to ubiquitin and small ubiquitin-like modifier (SUMO) modifications using a gene-knockout strategy in Fusarium venenatum, a mycoprotein fungus closely related to the fungal genetics model species Fusarium graminearum. Among the candidate genes, we specifically focused on the putative SUMO-associated gene UBQ14 based on phenotypic characteristics in F. graminearum. In the FvUBQ14 knockout mutant in F. venenatum, nutritional profiles showed prominent differences in amino acid and fatty acid composition compared to the wild-type strain. Furthermore, through proteomic analysis, we confirmed that the loss of FvUBQ14 leads to metabolic changes, particular in amino acid biosynthesis and degradation, resulting in an increase in amino acid composition in F. venenatum. Our findings provide new insights into filamentous fungal food improvement through genetic engineering and contribute to advances in alternative protein industry.