Thermophilic Fungi in Composts: Their Role in Composting and Industrial Processes

Thermophilic fungi are of broad interest due to their potential to produce heat-tolerant enzymes for biotechnological processes. They constitute a small fraction of the fungal biota that have a minimum temperature of growth at or above 20 °C and a maximum temperature of growth extending up to 60–62 °C. Composting is a promising source of new organisms and thermostable enzymes that may be helpful in environmental management and industrial processes. The process has raised much attention lately since it is also an environmentally sound method that avoids all pollution concerns. One of its benefits comes from its use in microorganisms to degrade organic waste into nutrient and produce organic fertilizer. While the current understanding tells us that bacteria are the dominant degraders in thermophilic composting processes, there is much to be said about the minority of thermophilic fungi during the composting process. This review covers the diversity of thermophilic fungi during composting, their role, and potential applications in biotechnology. The biotechnological applications of thermophilic fungi are numerous. They possess a variety of extracellular enzymes capable of hydrolyzing polymers such as starch, protein, pectin, hemicellulose, cellulose, and lignin. Several thermophilic fungi have already been used in industries involving food processing, bioconversion of organic materials, biodegradation of plastics, biosorption of metals/radionuclides, cancer treatment, and synthesis of nanoparticles.