Yarrowia lipolytica

Yarrowia lipolytica is a species of yeast-like fungus that acts as an opportunistic plant pathogen, primarily causing post-harvest decay. While often utilized in industrial microbiology, its presence in agricultural environments poses a significant risk to the quality and storage stability of various fruit and vegetable crops.

The host range of this pathogen includes various pomaceous and stone fruits, as well as several vegetable species. The fungus is particularly attracted to tissues that have already been compromised, whether by mechanical injury during harvest, pest feeding, or environmental stress such as frost or sunscald. Once an entry point is established, the fungus colonizes the substrate rapidly.

Symptoms of the infection typically manifest as localized soft rot. The affected areas of the fruit often darken and become depressed, eventually covered by a characteristic white or yellowish, creamy fungal bloom. This proliferation of fungal mass leads to the total degradation of the internal structure of the produce, often accompanied by an off-odor caused by the metabolic breakdown of fats and sugars.

The development of Yarrowia lipolytica is highly dependent on humidity levels. High relative humidity and poor ventilation are the primary drivers for the rapid spread of the fungus in storage facilities. Under these conditions, the fungal spores are easily dispersed, potentially contaminating entire lots of stored produce within a very short timeframe.

Management of this pathogen focuses primarily on preventative measures rather than curative chemical treatments. Producers should prioritize:

• Gentle handling during harvest to minimize surface wounds.
• Cleaning and sanitation of storage crates, pallets, and warehouse walls.
• Implementation of cool-chain management to slow fungal metabolism.
• Regular monitoring and removal of infected fruits to prevent secondary spread.