Influence of growth rates, microstructural properties and biochemical composition on the thermal stability of mycelia fungi

Mycelium fungal species exhibit fire retardant characteristics. The influence of the growth media on the fungal growth rates, biochemical composition, and microstructural characteristics and their relationship to thermal properties is poorly understood. In this paper, we demonstrate that molasses can support the growth of non-pathogenic Basidiomycota phylum fungal species producing bio-derived materials with potential fire retardation characteristics. Scanning electron microscopy and Fourier transform infrared (FTIR) spectrometry were used to interrogate the microstructural and biochemical properties of the molasses-grown mycelia species. Thermal decomposition of molasses-fed mycelia was evaluated via thermogravimetric analysis interfaced with FTIR for real-time evolved gas analysis. The morphological and microstructural characteristics of the residual char post-thermal exposure were also evaluated. The material characterization enabled the establishment of a relationship between the microstructural, biochemical properties, and thermal properties of molasses-fed mycelia. This paper presents a comprehensive exploration of the mechanisms governing the thermal degradation of three mycelial species grown in molasses. These research findings advance the knowledge of critical parameters controlling fungal growth rates and yields as well as how the microstructural and biochemical properties influence the thermal response of mycelia.