Use of solid phase microextraction (SPME) for profiling fungal volatile metabolites

Aims: The influence of isolation methods: solid phase microextraction (SPME) with different fibres and simultaneous distillation extraction (SDE) on the profile of isolated fungal volatile metabolites was investigated. Methods and Results: Four SPME fibre types: Polydimethylsiloxane, Polyacrylate, Carboxen/PDMS and Carboxen/Divinylbenzene/PDMS were evaluated in terms of their efficiency in extracting volatile metabolites emitted by Penicillium roqueforti grown on wheat kernel medium. All fibres showed varied efficiency and selectivity in extracting volatile compounds. Sesquiterpene hydrocarbons were the predominant fraction of volatile compounds isolated by all fibres, and ranged from 55.4 to 93.7% of all volatiles depending on the type of fibre used. Alcohols and ketones ranged from 2.7 to 20.5%, esters from 1.2 to 12.8%, and monoterpene hydrocarbons from 1.2 to 5.4%. Profile of volatile compounds obtained by SDE differed from SPME and the oxygenated sesquiterpenes formed the predominant fraction of volatiles isolated using SDE. Significance and Impact of the Study: The data in this study show that analysed profile of volatile compounds emitted by fungi is highly dependent on the extraction method.