Seminar of the Department of Microbiology
MSc Student Session 1
Pierre Koch – MSc candidate – UIBK
Cynthia Matlschweiger – MSc candidate – UIBK
Patrick Herzog – MSc candidate – UIBK
22.01.2026, 11:00
- Join online
- or in presence: Seminarraum Biologie - (Technikerstr. 25, Viktor-Franz-Hess Haus, Parterre)
Abstracts
Koch: Identification and characterization of a novel anaerobic gut fungus strain
Anaerobic gut fungi (AGF) are a peculiar fungal group that drastically gained in relevance over the past decade due to their innate and powerful ability to digest lignocellulosic biomass in an anoxic environment. They are capable of releasing up to 95% of the fermentable sugars from untreated plant material (Sijtsma & Tan, 1996). By employing their cellulosomes, i.e. multi-enzyme complexes of CAZymes, AGF could also be a potential player in making biogas production more efficient (Hess et al. 2020). With over 22 genera and 39 different species described so far, AGF form an ecologically coherent clade in the kingdom of Mycota (Hanafy et al., 2023; Nash et al., 2025; Prati et al., 2023). Through more intensified research, new strains are being discovered in wild herbivores and characterized with a systematic approach as described in Hanafy et al., 2022 and Elshahed et al., 2022. A recently discovered new strain, called LGB2, has been monocultured from the faecal samples of Rupicapra rupicapra.
Matlschweiger: Overexpression of the pks1 gene in Trichoderma atroviride P1 and complementation of a ∆pks1 mutant through a constitutive and Tet – ON promoter system
The genus Trichoderma belongs to the division of Ascomycota and is a filamentous fungus that can be found widespread in the world. It colonizes various ecosystems, like soil, forests and deserts, as well as different climatic zones, leading to findings in tropical regions or Antarctica. Characteristic for Trichoderma species is their rapid growth by utilizing diverse substrates, strong spore production as well as the production of secondary metabolites. Several species of this genus serve as biological biocontrol agents in agriculture, since Trichoderma is resistant to many toxic chemicals, herbicides and organic pollutants. Additionally, also volatile organic compounds (VOC) produced by Trichoderma species influence their biocontrol activity by inhibiting the growth and development of plant pathogens or activating the plant defence. An important volatile secondary metabolite is 6 – pentyl – alpha – pyrone (6-PP), a ketone known to be produced by thirteen Trichoderma species, which is recognized for its organoleptic characteristics; a strong coconut – like aroma. Benefits of 6 – PP are its antifungal, antibacterial and plant – growth promoting bioactivities. The production varies by different environmental stimuli such as nutrient availability or light influences. The biosynthesis is governed by the polyketide biosynthesis pathway and recently, the gene pks1, was found to be responsible for 6 – PP biosynthesis in T. atroviride. To enhance the 6 – PP biosynthesis and benefit from the produced secondary metabolite, an overexpression of the pks1 gene using a CRISPR/Cas9 approach shall be established. The overexpression is achieved by two different systems: inserting a second copy of the pks1 gene under the constitutive gapdh promotor or expressing pks1 under control of the Tet – ON promoter system, which is induceable by the addition of doxycycline. Additionally, a complementation of the ∆pks1 mutant strain was be made by reinserting a functional copy of the pks1 gene, to prove that this gene is the decisive factor for 6 – PP production. After succesful genotyping, comparative assays between the wildtype P1, the ∆pks1 mutant strain and the resulting putative pks1-overexpressing mutants regarding 6 – PP production, inhibitory activity as well as mycoparasitic confrontations with plant pathogens as hosts were carried out.
Herzog: Lytic life cycle regulation of HFTV2 in Haloferax volcanii
In this study, the halophilic archaeon Haloferax volcanii is used to investigate the life cycle regulation of the recently discovered virus HFTV2. Observations indicate that HFTV2 exhibits a concentration-dependent infection strategy: at low viral concentration, the virus follows a lytic cycle, leading to host cell lysis, whereas at high viral concentration, it adopts a lysogenic state and persists within the host.
This concentration-dependent switch suggests the presence of a signaling mechanism that enables sensing of viral population density and governs the decision between lytic and lysogenic life cycles. The molecular basis of this process is currently unknown. The aim of this master’s thesis is to contribute to a better understanding of the signaling and communication processes involved in HFTV2 infections of H. volcanii, which may provide insight into general communication systems in viral and virus-associated contexts.