Production of Mycelium-Based Nonwoven Fabrics via Submerged Fermentation

Fungal mycelium has emerged as a promising renewable raw material due to its carbohydrate- and protein-rich cell wall composition, its branched fibrous structure, and its ability to form well-connected fiber networks in materials such as nonwoven fabrics. Despite the potential, the applicability of mycelium-based materials is still limited due to low production throughput and the need for material development to meet performance requirements for demanding end uses. In this work, we investigated the use of mycelium obtained from submerged bioreactor cultivations as a basis for production of nonwoven sheets, with the goal of developing scalable processes toward efficient biomanufacturing. We studied how bioprocess conditions, biomass pretreatment, and formulation additives influence the nonwoven sheet tensile properties. Biodegradation tests, prototyping, and process scale-up trials were used to explore applicability and production feasibility. The mechanical properties of the mycelium sheets were strongly influenced by bioprocess conditions and mycelium pretreatment. Adding nanofibrillated cellulose fibers had a clear reinforcing effect. Formulations with nanofibrillated cellulose and plasticizers produced mycelium nonwoven sheets with ultimate tensile strengths of 11-19 MPa and fracture strains of 9-10%, depending on the mycelium pretreatment process applied. The materials biodegraded in aquatic environments within 28 days and showed rapid disintegration in industrial compost conditions within 1.5 months. Material finishing options were further demonstrated, and a prototype handbag was fabricated. Finally, a roll-to-roll production concept at a meter-scale was established. These results demonstrate that mycelium from submerged fermentation, when combined with a roll-to-roll material-forming process, offers a viable, scalable, and high-output route for efficient biomanufacturing of fiber-reinforced mycelium-based nonwoven fabrics.