Aflatoxin Production and Tolerance to Organic Acids byAspergillus flavusandAspergillus parasiticusIsolated from Acid Treated Moist Grain

Publisher Website
Google Scholar
Abstract
A total of 101 isolates of A. flavus/parasiticus originating from acid treated feeding grain in Sweden were identified according to conidial ornamentation. A. flavus was the most common (71% of all isolates) of the two species. Aflatoxin production was detected in 76% of the isolates. The highest toxin production was found in A. parasiticus isolated from formic acid treated grain. The non-toxigenic isolates were all A. flavus. Spores and mycelium were inoculated separately from all isolates on agar plates with 0, 0.1%, 0.3% and 0.5% (by weight) of formic or propionic acid. As for mycelium inoculations there was no difference between the acids; growth was only observed on agar with the lowest concentration (0.1%) of acids added. As for spore inoculations formic acid was less effective than propionic acid in inhibiting fungal growth. No growth was found on plates with 0.3% propionic acid but on plates with 0.3% formic acid growth was observed in 21% of the isolates, all originating from formic acid treated grain.