Development of the dichlorvos-ammonia (DV-AM) method for the visual detection of aflatoxigenic fungi

Area of Science:

• Agricultural Science
• Mycology
• Food Safety

Background:

• Aflatoxins (AFs) are toxic, carcinogenic metabolites from fungi like Aspergillus flavus.
• Accurate detection of AF-producing fungi is crucial for crop safety and regulation.
• Existing methods may lack sensitivity or visual clarity for field applications.

Purpose of the Study:

• To develop a novel, sensitive, and visual method for detecting aflatoxigenic fungi.
• To differentiate AF-producing fungi from other species.
• To enable rapid screening and characterization of fungal contamination in crops.

Main Methods:

• Development of the dichlorvos-ammonia (DV-AM) visual detection method.
• Utilizing dichlorvos (DV) to inhibit esterase in AF biosynthesis, leading to precursor accumulation.
• Applying ammonia (AM) vapor to induce a color change in fungal colonies.
• Investigating optimal culture conditions for enhanced color intensity.

Main Results:

• The DV-AM method successfully identified AF-producing fungi via a color change from light yellow to brilliant purple-red.
• The method demonstrated high sensitivity and visual clarity.
• Discrimination between Aspergillus section Flavi and other AF precursor-producing species was achieved.
• The DV-AM method proved effective for isolating nonaflatoxigenic fungi and screening inhibitors of AF production.

Conclusions:

• The DV-AM method offers a highly sensitive and visible indicator for detecting aflatoxigenic fungi.
• This technique supports crop monitoring, fungal characterization, and screening of AF inhibitors.
• The DV-AM method enhances food safety by enabling precise identification of toxic fungal contaminants.