The current petroleum-based non-degradable plastic packaging foams cause serious environmental pollution problems and place a burden on landfill. Fungal mycelium-based bio-foams are emerging waste-derived bio-degradable alternatives by utilizing fungal mycelium as the adhesive and waste as the substrate. Fungal mycelium is sustainable and plays an important role in developing mycelium-based biomaterial. However, with only a few species characterized, many unidentified species with the potential to construct high-quality mycelial materials are waiting to be explored.

This study evaluated the performance of mycelium-based biomaterials using six unexplored novel mycelium species (Fomes fomentarius, Flammulina velutipes, Trichaptum biforme, Coprinopsis macrocephalus, Trametes pubescens, Bjerkandera adusta) and two commonly used mycelium species (Pleurotus ostreatus, Ganoderma lucidum). This study also examined the performance of nutrient-supplied mycelium-based biomaterials and non-supplied mycelium-based biomaterials using three additional mycelium species (Pleurotus ostreatus, Ganoderma lucidum, Flammulina velutipes). A mother-culture based method was applied during the fabrication process of making mycelium-based biomaterials. The growth performance, morphological analysis, dry density, moisture content, shrinkage percentage, mechanical properties (firmness, compression modulus, recovery rate), thermogravimetric analysis, water absorption and thickness swelling properties of eleven mycelium-based bio-foams were investigated.

The results showed that the mycelium-based bio-foams' physical and mechanical properties depend on the mycelium species inherent characteristics and nutrient supplement conditions. Bio-foams made by Bjerkandera adusta and Fomes fomentarius had great colonization conditions, dense and solid tangled hyphae, thick hydrophobic mycelial skin, and similar density and mechanical properties to packaging foams. Additional nutrient supplements supported the mycelium growth on the substrate, increased bio-foams density, enhanced compressive firmness, and improved the recovery rate after compression. Besides commonly used mycelium species Pleurotus ostreatus and Ganoderma lucidum, the two novel mycelium species Bjerkandera adusta and Fomes fomentarius are promising fungal species for making mycelium-based packaging foams.