Seminar of the Department of Microbiology
MSc Student Session 1
Anna Oberdanner – MSc candidate – UIBK – Mykologie
Vincent Kopf – MSc candidate – UIBK – Mykologie
30.01.2024, 11:00
- Join online
- or in presence: Seminarraum Biologie - (Technikerstr. 25, Viktor-Franz-Hess Haus, Parterre)
Abstracts
Oberdanner: Evaluation of the interaction between the biocontrol agent Trichoderma atroviride and different bacterial strains
Trichoderma sp. are filamentous fungi, which are known to protect plants against pathogenic fungi by releasing cell-wall degrading enzymes or secondary metabolites. The health and productivity of crops can be improved by various plant growth-promoting bacteria (PGPB) from several genera, including Pseudomonas, Bacillus, Flavobacterium, Streptomyces and Micrococcus. BCAs as Trichoderma atroviride and PGPBs are commercially sold together as biopesticides, leading to a more beneficial effect for the growth and health of plants than a mono-inoculation. There is a lack of knowledge how they interact with each other and if the co-cultivation leads to any morphological/ growth changes or if the microorganisms produce any additional, potentially bioactive secondary metabolites. The aim of this thesis is to establish and describe the co-cultivation of T. atroviride with various bacterial strains and to investigate whether these co-cultivations lead to the production of any additional and bioactive metabolites. The first results show that the bacteria inhibit the growth of T. atroviride on solid media and lead to a different metabolite spectrum in the co-culture in comparison to the mono-cultivation.
Kopf: Investigation of multiple pex-genes in Trichoderma atroviride P1 by gene deletion and functional analysis
Peroxisomes are eukaryotic ubiquitous, highly adaptable organelles that play a vital role in fungal cells, like in the primary metabolism, ROS-removal, and secondary metabolite production. The biogenesis, function, and proliferation of peroxisomes are encoded by a protein group called peroxins. In the biotechnologically relevant genus of Trichoderma, very little research has been published on peroxins. Therefore, there is a strong need to investigate the peroxins and underlying pex-Genes in Trichoderma species like Trichoderma atroviride to understand and improve its biotechnological applications as a biocontrol agent. A bioinformatic analysis reveals that a total of 24 pex-Genes could be present in Trichoderma atroviride P1. Pex3, pex5, pex7, and pex11 were chosen for further investigation due to their crucial functions in other fungi. Relative gene expression levels revealed a slight upregulation for all selected genes when grown on alternative carbon sources. A significant protein-leakage of hyphae was observed in Δpex3- and Δpex5-mutants. This indicates the malfunction or absence of woronin-bodies as they are derived from peroxisomes. Furthermore, a biotin-auxotrophy was detected for the Δpex7-mutant, suggesting the involvement of the PTS2 pathway as an essential component of the biotin-metabolism.