Green and sustainable bioboards: Biomanufacturing of mycelium-based composite boards with tunable properties

The contradiction between the inefficient management of agricultural and food residues and the scarcity of natural resources is a critical issue that human societies must address to achieve sustainable development. Mycelium-colonized materials on organic residues can replace fossil-sourced polymers in material manufacturing, offering sustainable solutions. In this study, we evaluated the performance of mycelium-based composite bioboards (MBs) formed by hot-pressing Ganoderma lucidum mycelium incubated on straw and food residues, and explored the potential bonding mechanisms of mycelium in MBs as bioadhesives. We found that MBs exhibited internal bond strengths up to 1.53 MPa and static flexural strengths up to 8.91 MPa. These results can be attributed to hydrogen and amide-ester bonding between polysaccharides and proteins in the mycelium, and reducing sugars produced from lignocellulose degradation during hot-pressing. We also conducted multiaspect comparisons between the MBs and various commercial materials (plastics, plywood, natural wood, and plasterboard). It has been found that MBs possess advantages and application potential in mechanical properties, thermal barrier, flame retardancy, safety, cost, and sustainability. Although there are certain challenges and limitations regarding the water resistance of MBs, this work still offers further impetus for the development of bioadhesives and mycelium-based materials.