Determining key Growth factors and evaluating impact of Different Natural Coating Agents on Mycelium Bricks

Mycelium-based composites (MBCs) represent an emerging class of wholly bio-fabricated, carbon-neutral building materials grown through the controlled colonization of lignocellulosic substrates by fungal hyphal networks. This study evaluates their structural viability by combining a systematic literature review of peer-reviewed evidence with an original experimental investigation of 24 mycelium brick samples fabricated under home-controlled conditions. The research addresses four core objectives: identifying the governing parameters of mycelial growth, fabricating standard-sized bricks, and quantitatively evaluating the impact of natural coating agents on moisture absorption, density, and compressive strength relative to biodegradability requirements. Empirical testing revealed that uncoated bricks exhibit high moisture susceptibility, with a mean water absorption (WA) of 59.58%. However, the application of natural surface treatments significantly mitigated water uptake, reducing the mean WA to 15.21% for beeswax, 31.79% for shellac, and 40.87% for chitosan. Beyond moisture resistance, coating treatments influenced mechanical properties; beeswax coated bricks demonstrated superior performance, achieving the highest mean density of 0.20 g/cm³ and a peak mean compressive strength of 2.02 N/mm². These findings validate the established density–strength correlation and confirm that natural, bio-based coatings function as effective, fully biodegradable surface treatments.