Abstract
Trametes versicolor, Gloeophyllum trabeum and Poria placenta are known as wood destructive fungi, causing high economic losses in construction wood and wood composite products. To evaluate the quality of wood as raw-material for the production of high engineering property products, a reliable and sensitive detection of wood rotting fungi is needed. A rapid and non-destructive method for the evaluation of fungal infestation can focus on volatile organic compounds (VOC) released by fungi.
Beech wood (Fagus sylvatica) was inoculated either with G. trabeum, P. placenta or T. versicolor and incubated at 22 °C for one week prior to sampling of VOC. Volatiles released to the head space were collected using solid phase microextraction (SPME), 85 µm Carboxen/PDMS StableFlex fiber type, and were analysed by GC-MS. Each fungus growing on beech released a specific pattern of VOC. The detected VOC can be categorised into two broad groups, aliphatic C5-C8 compounds and isoprenoids. Typical fungal odour compounds like 1-octen-3-ol and 3-octanone were produced by all three fungi. Two monoterpenes, alpha-pinene and 3-carene were found. However, dominant components with respect to abundance were sesquiterpenes. Sesquiterpene patterns were characteristic for each species. Moreover, 6-protoilludene was specifically produced by G. trabeum in high amounts. Alpha- and beta-barbatene were typical and dominant VOC of T. versicolor.
Cis boleti, an insect typically feeding on fruiting bodies of wood rotting fungi like T. versicolor was used for electroantennographic recordings of fungal volatiles. On the basis of these measurements the feasibility of a biosensor for the detection of wood rotting fungi was assessed.