Hydrophobins line air channels in fruiting bodies of Schizophyllum communeand Agaricus bisporus

The hydrophobin SC4 was isolated from the medium of a dikaryon from Schizop hyllum commune with disrupted SC3 genes. Although not glycosylated, its bio physical properties were similar to those of SC3. As the hydrophobins SC3 f rom S. commune and ABH1 and ABH3 from Agaricus bisporus, SC4 self-assembled at hydrophilic-hydrophobic interfaces into an SDS insoluble amphipathic fi lm with a typical rodlet structure at its hydrophobic face, and also proved to be a powerful surfactant. Similar rodlet structures were observed in th e fruiting body plectenchyma. By immunodetection SC4 could be localized lin ing air channels within this tissue. A similar localization was found for t he ABH1 hydrophobin in fruiting bodies of A. bisporus. Probably, these hydr ophobin coatings prevent collapse of air channels allowing efficient gas ex change even under wet conditions.