Location: Food and Feed Safety Research
Title: Methods to Sample Air Borne Propagules of Aspergillus Flavus Authors
Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 2006
Publication Date: July 30, 2006
Citation: Bock, C.H., Cotty, P.J. 2006. Methods to sample air borne propagules of Aspergillus flavus. European Journal of Plant Pathology. 114:357-362. Interpretive Summary: The fungus named Aspergillus flavus produces a poison called aflatoxin when it infects several crops including cottonseed, peanuts and corn. Aflatoxin prevents crops from being used as either foods or feeds. A. flavus produces spores that spread this fungus between crops and from soil to crops. In order to study the biology of aflatoxin-producing fungi in the air, special techniques are required to trap and quantify the spores. In the current work, several techniques for trapping fungi in the air were developed and compared. We found several techniques used traditionally to trap fungi are not very good for aflatoxin producers. Techniques based on cyclone samplers were found to be very effective for the quantification of air-borne aflatoxin producing fungi. These samplers were found to have several characteristics that make them particularly useful under very dry, desert-like conditions. Cyclone samplers should be useful in the study of aflatoxin-producing fungi. These studies are necessary for scientists to develop strategies to prevent contamination.
Technical Abstract: Several techniques (cyclone samplers, filter samplers and rotorods) were evaluated for detection of airborne Aspergillus flavus Link propagules in a cultivated region of southwest Arizona. Cyclone samplers operated continuously for 168 h (7 d) collected a dry sample that was ideal for quantification of fungi through dilution plate technique. Measurements of conidia of A. flavus, and particle size caught by the cyclone sampler combined with filter retention studies, suggest that the predominant propagules caught by the cyclone sampler are conidia, rather than particles of sclerotia or infected vegetative matter. Where isolate culture and characterization is required, cyclone samplers are ideal for continuous monitoring of air borne A. flavus propagules.