Thermomyces lanuginosus

Thermomyces lanuginosus is a well-known thermophilic fungus recognized for its significant role in the degradation of organic matter and agricultural products. It thrives in high-temperature environments, making it a major concern in post-harvest technology and the storage of various grains and oilseeds.

This fungus typically attacks crops such as wheat, corn, soy, and other stored commodities. It is particularly prevalent in grain bulks that experience "self-heating," where metabolic processes raise the internal temperature of the grain mass to levels between 45°C and 60°C, creating a perfect habitat for the fungus to colonize rapidly.

Symptoms of infestation include the development of a brownish-grey or olive-colored mycelial mat on the surface of grains. As the pathogen breaks down starch and proteins, it causes significant changes in the chemical composition of the host material. This results in discolored seeds, unpleasant odors, and a marked reduction in seed viability and overall grain quality.

The conditions favoring the spread of Thermomyces lanuginosus are directly linked to poor moisture management and improper ventilation. When stored moisture levels are not regulated, biological activity within the grain mass accelerates. Once the temperature enters the thermophilic range, the fungus rapidly outcompetes other organisms, leading to severe spoilage.

Effective management and prevention strategies include:

• Ensuring proper post-harvest drying to bring moisture content below safe levels.
• Implementing automated temperature monitoring systems in silos to detect hot spots.
• Optimizing airflow and ventilation to prevent self-heating.
• Sanitizing storage facilities and machinery to reduce initial spore loads.

The economic impact of this fungus is substantial, as it leads to the degradation of stored grain value and potential contamination of feedstocks. Due to its intense enzyme production, including lipases and proteases, the presence of this mold can compromise the technological properties of grain, rendering it unsuitable for food production and industrial processing.