Sustainable Substrates for Mushroom Production: A Review

Abstract

Mushroom farming is gaining worldwide increasing recognition as an establishment of nutritional, therapeutic and economic importance. The biotechnological procedure utilizes various organic resources as substrates for the production of edible and therapeutically active fungal biomass. Traditionally, sawdust, composted manure and wheat straw were the essential substrates. Nevertheless, increasing demand for cheaper production and fungal-mediated bioremediation warrants the utilisation of alternative substrates. In addition, using unconventional farming inputs with parameters: agricultural residues (rice husk, corn stover, sugarcane bagasse) or industrial by-products (spent grains, coffee husks, brewery waste) or organic waste materials (food scraps, garden waste) can free up some precious resources. These are principles of sustainable agriculture and the circular economy, including resource conservation, reduced environmental contamination and higher mushroom production. Nevertheless, issues like pollutants, compositional heterogeneity, invasive plants and potentially pathogenic microorganisms can be encountered and must be addressed prior to substrate utilization e.g., through fermentation, steaming, or chemical pre-treatments to improve substrate safety and efficiency. Although established substrates have demonstrated efficacy, availability and resource recycling, they also share drawbacks like competition with other applications, seasonal availability, contamination threats, higher prices and ecological impacts. In the case of mushrooms, using alternative substrates comes with economic and costs benefits while being considered more sustainable, but there remain some other essential sustainability parameters like optimal growth condition, quality and variability of substrate and cost effective feasibility that needs thorough research and refinement of this strategy on large scale for transitioning from established mushroom species production with convention substrate to sustainable production practice by using alternative substrate. The paper highlights the utilisation of alternative substrates, including agricultural residues (e.g., rice husk and corn stover), industrial by-products (such as spent grains and coffee husks), and organic waste materials (including food scraps and garden waste), to address the increasing demand for sustainable and cost-effective practices in mushroom cultivation.