Mycelial growth of wood fungus Ganoderma sessile in porous scaffolds

Abstract

[EN] The mycelium of filamentous wood fungi exhibits adaptive growth strategies influenced by their host material. In 2D solid-state fermentation, densely packed substrates limit oxygen access, resulting in hyphal growth mainly at the substrate-air interface. To address this challenge, we investigated open porous scaffolds as growth environments for the filamentous fungus Ganoderma sessile, quantifying mycelial biomass formation via ergosterol content. This quantitative approach directly demonstrates a scaffold-associated biomass increase of 60% after 7 days compared to plate cultures and thus provides experimental evidence linking increased accessible surface area in porous substrates to enhanced biomass formation in solid-state fungal growth. Mycelium colonization of the hydrogel scaffold also enhanced their mechanical properties, including stiffness and elastic recovery. This scaffold-associated biomass increase was not observed for G. lucidum or P. ostreatus, underscoring a species-specific effect with ergosterol levels for G.sessile peaking at 2 wt% malt extract in the substrate, in contrast to both higher and lower malt extract concentrations. These findings improve our understanding of solid-state fermentation, highlight the importance of species-specific responses and guide the design of substrates for fungi-based materials with tailored properties.