Seminar of the Department of Microbiology

MSc Student Session 2

Markus A. Meitinger - AG Vrabl - University of Innsbruck

Benjamin Urban - AG Peitner - University of Innsbruck

 

16.11.2023, 11:00 - Join online or in presence HSB 4 (Technikerstraße 13b EG)

 

 

Abstracts

Meitinger: Screening the secondary metabolome of endophytic fungi through co-culturing

With the rising need for novel antibiotics, antifungals and biological pest control in agriculture, the search for compounds which are usable in the context of human health and agriculture is becoming a important challenge for modern microbiology. Because of the developments in genome sequencing a lot of silent gene clusters have been found in filamentous fungi which pose great potential for novel chemical diversity. This raises the question on how to trigger the expression of such gene clusters which code for the synthesis of natural products (secondary metabolites). 

This study aims to trigger the biosynthesis of natural products through cultivation in dual-culture as well as OSMAC-approach. 

The metabolome of mono and dual-cultures is analyzed and characterized with high performance liquid chromatography and mass spectrometry. 

Urban: Comparison of fungal leaf endophyte communities from two alpine medicinal plant species

Fungal endophytes are symbionts that inhabit the tissues of all terrestrial plants. They can provide beneficial effects to the plant while gaining advantages themselves, but there exist also latent pathogens which can change to a parasitic lifestyle under special conditions. While mutualistic symbionts of plant roots and fungal endophytes of grasses were studied extensively in the past, more recent investigations also focus on foliar endophytes from herbaceous species, aiming at the discovery of secondary metabolites.  

In this study, we isolated leaf endophytes from two alpine medicinal plants, Arnica montana and Anthyllis vulneraria. The endophytic fungi were isolated using the surface sterilization method and identified by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA. The study aims to understand the influence of plant species and habitat on endophyte communities and to generate basic data on the endophytic fungal diversity in alpine habitats. We compared the occurrence of endophytic fungi in the two plant species and on different sites to understand their potential mode of transmission and answer the question of whether they are host specific. Both plant species harboured a diverse community of endophytic fungi. We isolated 22 different OTUs from Anthyllis vulneraria and 18 from Arnica montana, including many taxa which are known for their pathogenicity like Colletotrichum, Ramularia, Septoria, Cladosporium, Alternaria. Three groups showed a certain host specificity (Colletotrichum spp., Ploettnerulaceae sp. 1 and 2 and Ramularia spp.), being found only in one of the two plants, while most common taxa were found in both species. Septoria sp., which is our most common isolate, was the only OTU found in all 5 habitats. There was no common, site-specific endophyte. 

Due to their occurrence patterns, we could provide additional data on endophyte ecology, including host-range and mode of transmission.