Peptaibol-Containing Extracts of Trichoderma atroviride and the Fight against Resistant Microorganisms and Cancer Cells

Abstract

Fighting resistance to antibiotics and chemotherapeutics has brought bioactive peptides to the fore. Peptaibols are short α-aminoisobutyric acid-containing peptides produced by <i>Trichoderma</i> species. Here, we studied the production of peptaibols by <i>Trichoderma atroviride</i> O1 and evaluated their antibacterial and anticancer activity against drug-sensitive and multidrug-resistant bacterium and cancer cell lines. This was substantiated by an analysis of the activity of the peptaibol synthetase-encoding gene. Atroviridins, 20-residue peptaibols were detected using MALDI-TOF mass spectrometry. Gram-positive bacteria were susceptible to peptaibol-containing extracts of <i>T. atroviride</i> O1. A synergic effect of extract constituents was possible, and the biolo-gical activity of extracts was pronounced in/after the peak of peptaibol synthetase activity. The growth of methicillin-resistant <i>Staphylococcus aureus</i> was reduced to just under 10% compared to the control. The effect of peptaibol-containing extracts was strongly modulated by the lipoteichoic acid and only slightly by the horse blood serum present in the cultivation medium. Peptaibol-containing extracts affected the proliferation of human breast cancer and human ovarian cancer cell lines in a 2D model, including the multidrug-resistant sublines. The peptaibols influenced the size and compactness of the cell lines in a 3D model. Our findings indicate the molecular basis of peptaibol production in <i>T. atroviride</i> O1 and the potential of its peptaibol-containing extracts as antimicrobial/anticancer agents.