Volatile organic compounds emitted by mycoparasitic fungi Hypomyces perniciosus and Cladobotryum mycophilum suppress the growth of Agaricus bisporus

Hypomyces perniciosus and Cladobotryum mycophilum are mycoparasitic fungi infecting Agaricus bisporus and causing wet bubble and cobweb diseases, respectively. In this work, the role of volatile organic compounds (VOCs) emitted by these fungal mycoparasites in the suppression of A. bisporus was investigated. The VOCs of H. perniciosus and C. mycophilum effectively reduced the mycelial growth of A. bisporus by 60% and 73% after 5 days of incubation, respectively, compared to that of the control as assessed by the two-sealed-base-plates assay. Further, the VOCs of H. perniciosus and C. mycophilum were collected in a headspace solid-phase microextraction procedure, and their components analysed by means of gas chromatography-mass spectrometry. Ethanol was identified as the major volatile component in H. perniciosus and C. mycophilum. Ethanol vapour significantly retarded the growth of A. bisporus in an in vitro assay. The results of this study suggest that ethanol produced by H. perniciosus and C. mycophilum could be involved in the suppression of A.