Use of headspace solid-phase microextraction and headspace sorptive extraction for the detection of the volatile metabolites produced by toxigenic Fusarium species.

An efficient methodology was developed to determine the growth of toxigenic Fusarium spp., based on headspace solid-phase microextraction (SPME) and stir bar sorptive extraction of the fungal volatile metabolites produced. SPME and headspace sorptive extraction (HSSE) were used to monitor the de novo production of sesquiterpene hydrocarbons, such as trichodiene, a volatile marker and intermediate in the biosynthesis of trichothecenes. On growth media such as malt extract agar and potato dextrose agar, it was found that trichodiene was produced by toxigenic strains of Fusarium sambucinum and Fusarium sporotrichioides. It was the main volatile metabolite in the headspace extract of the cultures. On the other hand, deoxynivalenol producing Fusarium graminearum showed a completely different pattern of volatile sesquiterpenes and could easily be distinguished from a zearalenone producing strain of F. graminearum based on the headspace profile. Hence, it can be concluded that headspace analysis of volatile fungal metabolites by SPME and HSSE in combination with gas chromatography/mass spectrometry is a suitable monitoring technique to differentiate toxigenic strains of Fusarium.