The Light of Us: Photoantimikrobielle Aktivität von Extrakten ausgewählter Arten der Gattung Talaromyces
Student/in: Friederike Luise Glauch, BSc
Termin: 23.03.2026, um 10:15 Uhr
Ort: Seminarraum 1 (ICT Gebäude)
1. Prüfer/in: Mag. Dr. Pamela Vrabl
2. Prüfer/in: : ao. Univ.-Prof. Mag. Dr. Ursula Peintner
Vorsitzende/r: assoz. Prof. Dr. Martina Höckner
Interessierte Kolleginnen und Kollegen sind herzlich willkommen!
Abstract
The global overuse of antibiotics has driven a resistance crisis, with projections of up to 40 million deaths by 2050. Alternative therapies like photodynamic antimicrobial chemotherapy (PACT), using light-activated photosensitizers (e.g., anthraquinones), are being investigated and work independently of existing resistances. Fungi from Penicillium and Talaromyces spp. show promise as sources of such compounds. This study aims to characterize fungal extracts and their biological activities using the PhotoMIC technique.
Crude extracts from T. islandicus, P. restrictum, and T. stipitatus grown on different media, and isolated photosensitizers (i.e., iridoskyrin, islandicin), which were previously identified as photoactive from cell culture experiments (Vanessa Kern, Carmen Bendetta, Angelika Seeber), were tested in this study at different concentrations for photoantimicrobial activity against Candida albicans, Escherichia coli, and Staphylococcus aureus in 96-well plates (450 nm, 30 J/cm², ~15 min).
The culture medium had a significant effect on both light- and dark-induced toxicity of the fungal extracts, which was in line with the data found in the cell culture experiments. However, the photoantimicrobial activity was dependent on the test strain: For example, T. islandicus crude extracts showed strong phototoxic activity against C. albicans and S. aureus, but not against E. coli. Interestingly, the photosensitizers iridoskyrin and islandicin isolated from apolar T. islandicus extract fractions, which had performed well in cell cultures, showed no phototoxic activity against any test organisms. This indicates the presence of a further unknown photosensitizer in the polar fractions. Phototoxicity testing of the polar fractions is ongoing, and the first results underline this assumption.