Volatile Profiles of Toxigenic and Non-to xigenic Aspergillus flavus Using SPME for Solid Phase Extraction

Toxigenic and atoxigenic strains of Aspergillus flavus were grown on potato dextrose agar (PDA) and wetted (23% moisture) sterile, cracked corn for 14 and 21 days, respectively. Volatile compounds produced by A. flavus, as well as those present in the PDA controls and sterile cracked maize, were collected using solid-phase micro-extraction (SPME) and identified by gas chromatography/mass spectrometry. Results show that growth substrate had a major impact on the number and type of volatiles detected. Growth on sterile cracked maize produced many more volatiles than did potato dextrose agar. There were also differences observed in the type of volatiles produced between toxigenic and non-toxigenic isolates, as well as between isolates of the same toxigenic grouping.