Modified recipe to inhibit GSK-3 for the living fungal biomaterial manufacture

Living fungal mycelium with suppressed or abolished fruit-forming ability is a self-healing substance particularly valuable biomaterial for further engineering and development in applications such as monitoring/sensing environmental changes and secreting signals. The ability to suppress fungal fruiting is also a useful tool for maintaining stability (e.g., shape, form) of a mycelium-based biomaterial with ease and lower cost. The objective of this present study is to provide a biochemical solution to regulate the fruiting body formation to replace heat killing of mycelium during production. We discovered that GSK-3 activity directly correlates with the development of fruiting bodies in fungi, especially mushroom forming fungi such as Coprinopsis cinerea. By regulating GSK-3 expression and activity, one can control the fungal fruiting body development. We successfully demonstrated that treatment of an inhibitor of GSK-3 kinase activity resulted in acceleration in mycelium growth rate, absence of fruiting body and general decrease in GSK-3 gene expression. Therefore, GSK-3 inhibitor is suggested to be included in the mycelium cultivation recipes for regulating the growth of fungal mycelium and for inhibiting the development of fruiting bodies. This is the first report of using a GSK-3 inhibitor, such as lithium or any other GSK-3 inhibitor, to suppress or abolish fruiting body formation in living fungal mycelium-based biomaterial. It also provides an innovative strategy for easy, reliable, and low cost maintenance of biomaterial containing live fungal mycelium.