Thermomycosis

Thermomycosis is caused by thermophilic fungi of the genus Thermomyces, specifically Thermomyces lanuginosus. These microorganisms are unique due to their ability to thrive at high temperatures that inhibit most other biological life.

These fungi are saprophytic organisms that possess strong cellulolytic and amylolytic enzyme systems. They effectively break down organic matter in stored grains, seeds, and agricultural products.

The fungus produces a dense, whitish-to-brownish mycelium that permeates the substrate. The high heat generated by its metabolism creates a self-sustaining cycle of temperature increase.

Thermophilic spores of Thermomyces are highly resistant to environmental stress. They can remain viable for years, contaminating grain storage facilities, transportation belts, and drying machinery.

Because they are thermophilic, their biological cycle accelerates as the temperature rises. This distinguishes them from typical storage molds that prefer cooler or moderate temperatures.

The development of thermomycosis is primarily linked to the self-heating of bulk stored materials. This occurs when high-moisture seeds are stored without proper initial drying.

High moisture content in seeds combined with poor aeration creates the ideal microenvironment for Thermomyces. The respiration of the grain and the fungi themselves causes heat entrapment.

Storage silos or warehouses lacking adequate ventilation systems are high-risk areas. If heat cannot escape the grain bulk, the temperature quickly reaches the optimal range for the fungus (40–55°C).

Impurities such as dust, chaff, and damaged grains act as food sources and thermal insulators. Their presence within the grain mass dramatically increases the risk of mold outbreaks.

Poor management of silo temperature monitoring is a key factor. Without precise data on internal heat spots, the infection can spread throughout the entire volume of stored goods.

The primary impact of thermomycosis is the total loss of germination potential in seeds. The fungal enzymes destroy the embryonic tissue, rendering the batch useless for planting.

The nutritional quality of the grain is severely compromised, leading to lower protein and fat contents. This makes the product unsuitable for food or high-quality animal feed.

Fungal infection can result in the accumulation of hazardous mycotoxins. These toxins represent a significant health risk to livestock, often leading to reduced growth or mortality.

Economic damage is substantial, as an infected batch often requires disposal rather than being sold. It represents a total loss of investment in crop production and storage.

Physical clumping and crusting of the grain occur as the mycelium binds particles together. This creates significant mechanical issues during the unloading process from large silos.

The most important control measure is drying the crop to a safe moisture level before storage. Moisture management is the primary barrier against all storage-borne fungi.

Installation and maintenance of aeration systems are vital. Moving ambient air through the grain mass prevents heat accumulation and keeps the grain at safe, cool temperatures.

Regular sanitation of grain storage facilities is essential. Thorough cleaning and disinfection of bin interiors help eliminate fungal spores from previous seasons.

Frequent temperature checks using digital sensors allow for early detection of hotspots. Detecting a rise in temperature enables farmers to address the issue before colonization begins.

Effective screening and pre-cleaning of the harvest to remove chaff and fine debris limit the availability of nutrients for Thermomyces and improve the airflow through the pile.