A comparative study of mycelium films from nine fungal species for biocomposite applications

Mycelium-based biocomposites (MBC) offer a sustainable alternative to synthetic materials due to their biodegradability and low environmental impact. This study examined the structural and mechanical properties of mycelium films produced from nine fungal species representing monomitic, dimitic, and trimitic hyphal systems. These species were selected following preliminary screening of 21 strains for growth characteristics and mechanical performance. Growth rates varied significantly, with Irpex lacteus exhibiting the fastest growth (8 mm/day), while Fomes fomentarius and Daedaleopsis confragosa grew more slowly but exhibited superior mechanical strength. Tensile testing identified D. confragosa as the strongest fungus (6.51 MPa), followed by F. fomentarius, although considerable variability was noted. Ganoderma spp. and Trametes spp. showed moderate to low tensile strength. No consistent correlation was found between mycelium density and tensile strength, nor did chitin content alone explain mechanical performance. For instance, I. lacteus had the highest chitin content but weak tensile properties. Scanning electron microscopy revealed differences in hyphal diameter, density, and cell wall structure, indicating that factors such as glucan-chitin interactions and hyphal morphology influence mechanical behavior. These findings highlight the potential of less investigated fungal species in advancing MBC development.