Candida kefyr

Candida kefyr (often identified as Kluyveromyces marxianus) is a yeast species that functions as a post-harvest phytopathogen. While primarily known for its role in dairy fermentation, it can act as a causative agent for the decay of various fruits and vegetables, causing significant economic losses for producers and distributors alike.

The disease caused by this pathogen is classified as yeast rot. The infection process begins when the yeast enters plant tissues through wounds, surface cracks, or insect punctures. Once inside, the yeast cells multiply rapidly by budding, secreting enzymes that degrade the structural integrity of the plant cell walls, leading to the rapid softening of the infected tissues.

Target crops include those with high sugar content and significant water availability, such as grapes, tomatoes, apples, and various stone fruits. Because the pathogen thrives in environments where sugars are accessible, it is particularly problematic in crops that have reached peak maturity or are close to over-ripening, as their protective epidermal layers are more susceptible to breach.

Symptoms of Candida kefyr infestation are distinct. Affected areas of the fruit typically become soft, watery, and discolored. A signature diagnostic feature is the distinct odor of fermentation, often described as yeasty or slightly acidic. In conditions of high humidity, a thin, creamy-white microbial film or fuzz may develop on the surface of the lesion, consisting of an massive accumulation of yeast cells.

Effective management and prevention of Candida kefyr focus on minimizing opportunities for fungal entry and inhibiting yeast growth during storage. Key practices include maintaining low, stable temperatures in storage facilities to slow down metabolic activity, ensuring rigorous hygiene in packing houses to prevent the spread of spores, and removing any mechanically damaged or overripe fruit before they are placed into long-term storage.