Green chemical conversion of whole fungal mycelium into biodegradable films for sustainable material development

The escalating environmental impact of petroleum-based plastics demands the urgent development of sustainable, bio-based alternatives. While most research has focused on biopolymers derived from cellulose and plant or animal proteins, fungal mycelium has only recently emerged as a promising biomaterial. This PhD project explores the unexploited potential of fungal mycelium, as a renewable resource within a circular economy framework. A novel, streamlined chemical process was developed to produce biodegradable films directly from the whole mycelial mass, effectively bypassing the energy- and resource-intensive chitin purification step required in conventional methods. The primary objective was to establish an environmentally friendly and efficient route for converting the entire Pleurotus ostreatus mycelium into high-performance, tunable films. The resulting fungal films demonstrate the feasibility of using unrefined mycelial biomass as a sustainable and cost-effective platform for applications ranging from food packaging to biomedical engineering and flexible electronics. The research combined green chemical processing and materials engineering. A mild alkaline treatment with ammonia, using glycerol as a plasticizer, was optimized to convert the whole mycelial mass into flexible films. In the first phase, process parameters, such as incubation time and plasticizer content, were systematically studied to assess their effects on film morphology, physicochemical properties, mechanical performance, water vapor permeability, and biodegradability. In the second phase, natural additives such as wax and antioxidant-rich carminic acid were incorporated to tailor barrier and bioactive properties for packaging and biomedical uses, respectively. Finally, the films were evaluated as precursors for laser-induced graphene (LIG) to explore their potential in flexible electronics. The developed method successfully produced homogeneous, flexible, and biodegradable films without requiring purification steps. These films exhibited competitive mechanical strength compared to previously reported Pleurotus ostreatus films and other mushroom biomass, confirming the effectiveness of the alkaline–plasticizer treatment approach. The incorporation of natural wax significantly reduced water vapor permeability to levels comparable to polylactic acid (PLA), confirming suitability for food packaging applications, while carminic acid conferred fibroblast biocompatibility, confirming suitability for biomedical applications. Moreover, direct laser processing enabled the formation of LIG patterns, demonstrating the versatility of the films as green precursors for conductive materials.