Pure mycelium materials production from agri‐processing water: Effects of feedstock composition on material properties for packaging applications

In this work, pure mycelium materials (PMMs) were produced by cultivating fungi Trametes versicolor and Irpex lacteus on lignocellulose-rich agricultural processing water. This water was a side stream from the alkali treatment of purposely grown biomass (miscanthus) for cellulose fiber extraction and contained lignocellulosic residues. Agri-processing water yielded ~75-mg/L PMMs with superior mechano-physical properties than synthetic medium-based ones. These properties were further enhanced by PMM post-processing with glycerol. The thermal stability of PMMs was demonstrated by their higher melting temperature than low density polyethylene (LDPE) while their degradation between 200-380°C, and density of <1.0 g/cm3, like LDPE. Their mechanical performance was studied on filmlike specimens via dynamic mechanical analyzer. PMMs showed a viscoelastic behavior with a high storage modulus of 34 MPa at 65°C suggesting their suitability for packaging applications. This work provides guidelines on optimizing PMM production using agri-processing water to obtain tunable mechano-physical properties. PRACTITIONER POINTS: Valorization of agri-processing water to produce high-value PMM packaging products. No pure or expensive nutrient supplementation was needed for agri-based feedstock. Relationships between feedstock composition and PMM properties were established. PMMs showed a similar thermal profile and density as typical petro-based packaging materials. The addition of glycerol postproduction induced flexibility in PMMs.