Mycelium-based leather-like material from Absidia koreana grown on agro-residues: Process optimisation, functionalisation, and material performance

Abstract

Developing sustainable, eco-friendlier leather-like material using fungal mycelium is a promising solution to environmental, animal welfare, and human health concerns associated with the traditional leather industry. Thus, having identified Absidia koreana BN223 as a fungus with potential for mycofabrication, its growth and biomass production were optimised using readily available agro-residues. Subsequently, the mycelium was processed into a biomaterial with a leather-like appearance through deacetylation, crosslinking, plasticisation and surface coating; after which selected functional properties were evaluated. Results indicated wheat bran and casein as the most effective carbon and nitrogen sources, respectively, for A. koreana mycelium production. Further, response surface methodology-based optimisation culminated in a 2.7-fold increase in biomass. The processed mycelial mat exhibited thermal stability up to 230 °C with increased compactness and uniform morphology relative to the raw mycelium, indicating improved surface consolidation. The leather-like material had an ultimate tensile strength, elongation at break and Young's modulus of ~3.18 MPa, 3.53% and 159.65 MPa, respectively, while also exhibiting a flexural rigidity of 89.73 μNm, a bending modulus of 16.01 MPa, and a critical tearing energy of 2.4 N/mm. Furthermore, benchmarking the material properties within the ANSYS framework indicated a comparable mechanical performance to the commercial leather analogues, Muskin and Pinatex. The biomaterial also displayed enhanced hydrophobicity, with water absorption decreasing 15.22 times compared to the untreated material, and water contact angle up to 96.23 °C. These findings lay the foundation for a waste-to-wealth approach to producing sustainable mycelium-based materials, with potential applications in the fashion industry, especially in low-stress leather applications and packaging, among others. Future studies on life cycle assessments and technoeconomic analyses are needed to validate the cost-effectiveness and environmental friendliness of the developed material. • Statistically optimised production increased A. koreana mycelium by 2.7-fold. • Mycelial-based biomaterial with thermostability of ~230 °C and tensile strength of 3.18 MPa. • Processing enhanced hydrophobicity, decreased water absorption with a contact angle up to 96.23°. • Sustainable mycelial-based leather substitute with potential in fashion and packaging.