Saccharomycopsis capsularis

Saccharomycopsis capsularis is an ascomycetous yeast species that acts as a significant agent of biodeterioration in agricultural products. In the context of agronomy, it is primarily recognized for its role in the degradation of stored grains and oilseeds. While not a direct pathogen of growing field crops, its impact during the post-harvest phase can be economically devastating.

The fungus functions by colonizing substrates rich in carbohydrates. Through its metabolic activity, it causes fermentation, which alters the chemical composition of the stored product. This process not only affects the aesthetic quality but also significantly diminishes the nutritional value and viability of seeds, rendering them unsuitable for planting or industrial processing.

Crops most susceptible to this fungus include wheat, corn, rice, and various oilseeds. The pathogen is opportunistic, often thriving in storage environments where temperature and moisture control are inadequate. High humidity levels are the primary trigger for the rapid colonization and spread of these yeast-like organisms.

Symptoms of infestation include:

• a creamy or whitish film or dust on the grain surface;
• a distinct fermented, sour, or yeast-like odor;
• hot spots within stored grain piles due to microbial activity;
• loss of seed germination potential;
• discoloration of the seed coat resulting from metabolic byproducts.

Effective management requires strict adherence to post-harvest handling protocols. Drying grain to a safe moisture content (typically below 14%) and maintaining proper aeration in storage bins are the most critical preventative measures. Routine monitoring of grain temperature and the use of sanitizing agents for storage facilities are essential strategies to mitigate the risks associated with this fungus.