Preliminary characterization of hydrophobins from a Bjerkandera sp.

Hydrophobins are fungal proteins that have the ability to change the hydrophobic or hydrophilic nature of a surface once they self-assemble into an amphipathic membrane at the surface interface. Their potential for industrial applications is high and since their discovery in a Schizophyllum commune isolate, hydrophobins from different species have been isolated and sequenced. As a general characteristic they present similar hydropathy patterns, high percentage of cysteine residues but low sequence homology even within same genera. Three strains, two fungal unidentified isolates and Bjerkandera sp. BOS55 from the laboratory collection were tested for hydrophobin production. Fungal ITS amplification and sequencing allowed the identification to species of the isolates, respectively, Mucor circinelloides and Trichoderma harzianum. Hydrophobins from all three strains were produced, extracted and preliminarily characterized. A never described antimicrobial activity, as well as biofilm formation inhibition for Candida albicans was detected for hydrophobin solutions. Further more, isolation and preliminary characterization of hydrophobins from Bjerkandera sp. is also described for the first time. Purification and isolation of these proteins was performed by HPLC and MALDI-TOF sequence characterization is under way.