Edible mycelium bioengineered for enhanced nutritional value and sensory appeal using a new synthetic biology toolkit

Genetic engineering of filamentous fungi has promise for accelerating the transition to a more sustainable food system and enhancing the nutritional value, sensory appeal, and scalability of microbial foods. However, genetic tools and demonstrated use cases for bioengineered food production by edible strains are lacking. Here, we developed a synthetic biology toolkit for Aspergillus oryzae, an edible fungus traditionally used in fermented foods and currently used in protein production and meat alternatives. Our toolkit includes a CRISPR-Cas9 method for genome integration, neutral loci, and new promoters. We use these tools to enhance the elevate levels of the nutraceutical ergothioneine and intracellular heme in the edible biomass. The biomass overproducing heme is red in color and is readily formulated into imitation meat patties with minimal processing. These findings highlight the promise of genetic approaches to enhance fungal meat alternatives and provide useful engineering tools for diverse applications in fungal food production and beyond.