Molecular and Cellular Biology
We investigated the effects of different substrates (potato dextrose agar [PDA], nutrient agar [NA], and corn meal agar [CMA]) and temperatures on growth and aflatoxin production in Aspergillus flavus. Contaminated peanuts from retailers at different locations in Georgia were used throughout the experiment and 200 seeds were selected from each sample. PDA, NA, and CMA served as the substrate to express the mold from the contaminated seeds. Seeds were plated equidistantly on each of the media and incubated at 10° C, 27° C, 30° C, and 37° C, respectively. Seeds incubated on moist filter paper served as control. Neither growth of A. flavus nor detectable levels of aflatoxin was observed at the temperature of 10° C on any of the media. While no growth of this mold was observed at a temperature of 37° C in most media, some growth was seen in PDA media at this temperature. However, maximum growth of A. flavus, along with detectable levels of aflatoxin, was attained at the temperatures of 27° C and 30° C. Of the three media tested, PDA supported vigorous growth of A. flavus at the temperatures of 27° C and 30° C.
Georgia Journal of Science