The Impact of Fungal Developmental Structures on Mechanical Properties of Mycelial Materials

This study explores how suppressing asexual development in Aspergillus nidulans enhances the mechanical properties of mycelial materials. Using four aconidial mutants (∆brlA, ∆flbA, ∆fluG, and fadA^G42R ) lacking asexual development and a control strain (A28) that undergoes typical asexual development, we found that the absence of asexual development significantly improves mechanical strength. All mutants exhibited higher ultimate tensile strength (UTS) than the control, with ∆fluG and ∆brlA (fluffy nonsporulating, FNS phenotype) showing the highest UTS. Additionally, fadA^G42R and ∆flbA (fluffy autolytic dominant, FAD phenotype) demonstrated significantly higher strain at failure (SF), linked to increased autolysis and lower dry cell mass compared to the control and FNS mutants. Solid-state NMR analysis suggests that autolysis in FAD mutants may disrupt galactofuranose-related processes, altering cell wall composition and contributing to higher elasticity. These findings suggest suppression of asexual development increases mycelial material strength, while autolysis mechanisms influence elasticity. This research highlights the potential for genetic manipulation in fungi to engineer advanced mycelial-based materials with tailored mechanical properties.