Biofabrication of mycelium-fabric biocomposites from textile residues

The chitinous fibrous network of mycelium has recently been implemented as a sustainable packaging or leather alternative. Other endeavors are currently explored given the environmentally friendly biofabrication process, suitable mechanics, flame resistance, and insulative properties. In this proof-of-concept study, we explore the potential of mycelium (Pleurotus ostreatus) to form bio-blocks by propagating across cotton, polyester, and mixed shredded textile fabrics (MSTF). Biocomposites showed distinct colonization patterns as a function of inoculation condition and textile type. Cotton-based composites demonstrated good structural integrity, reaching a flexural strength of 82.5 kPa and a toughness of 3298 kJm−3. Polyester-based composites exhibited a similar flexural strength of 80.5 kPa but showed nearly half the toughness at 1414 kJ/m−3. Flammability tests revealed flame extinction after 30 s in cotton composites, with 40 % of the area burned, whereas polyester composites reduced the combustion rate by 76 %. A comprehensive life cycle assessment (LCA) focusing on environmental impacts shows a cradle-to-gate commercial-scale climate change potential of 0.05 and 4.28 kg-CO2-equiv per kilogram of biobrick considering renewable-based and fossil-based energy mix scenarios, respectively. Our findings establish mycelium as an effective binding agent for textiles towards the formation of materials with complex forms benefiting from the inherent attributes of textiles.