Bachelor/ Master Thesis
The department of Microbial Drugs offers BSc/ MSc Thesis themes for students in the fields of Biology, Chemical Biology, Chemistry or Biotechnology. Topic 1: Isolation and Characterization of bioactive secondary metabolites of Xylariaceae (Fungi) from Argentina, Kenya and Thailand. Topic 2: Primer development for improvement of the amplification of housekeeping-genes in Xylariales (Sordariomycetes) in view of a multi-gene genealogy.
Area of research
The rising antibiotic resistance is a big threat to the global public health and is one of the biggest challenges for the modern society. Fungi are a great source for the discovery of natural molecules that could be used for the development of new drugs with antibiotic properties. The Xylariaceae, currently counting over 1300 accepted species, is one of the largest and widely distributed families of the Ascomycota and show a high variety in their morphological appearance, as well as in the production of secondary metabolites. Even though some genera of this family are known and have been described for over 200 years and comprehensive studies about their morphological characteristics and secondary metabolite production are available, new species and metabolites of this family are constantly being encountered. During our recent expeditions in the course of an international collaboration network, we have found several interesting specimens that are now about to be studied.
Since our ongoing work has revealed that secondary metabolite production is strongly correlated with phylogenetic data, we are using modern methods of biodiversity research as a means of preselection to increase the chances to find new template molecules for drug development.
Aim of Topic 1
The goal of the project is to study recently stromata (fruiting bodies) of Xylariaceae from Argentina, Kenya, and Thailand in respect to morphology and production of secondary metabolites. Secondary metabolites are extracted from the stromatal material and analyzed by HPLC-DAD/MS. Thereafter, the interesting compounds are purified by preparative HPLC and other chromatographic methods and tested for biological activities and their structures of novel compounds are elucidated via high resolution mass spectrometry and NMR spectroscopy and other spectral methods. The structure elucidation will be accomplished by the postdocs of the MWIS department, but the BSc and MSc candidates will be integrated in the process. Aside from the studies of their secondary metabolites, the specimens will also be subjected to morphological studies including light and scanning microscopy.
Aim of Topic 2
The cultures of the above mentioned species are cultivated at small scale to genomic DNA extraction and different primers are used to amplify phylogenetically relevant DNA loci. Since the ubiquitously used fungal barcode (5.8S/ITS nrDNA) has proven insufficient to attain a resolution at the species level in most taxa of the Ascomycota, we aim at combining rDNA and so-called housekeeping genes (RBP2, beta-tubulin, TEF) in order to establish a stable phylogeny. The characteristics of the new strains will be compared with those of reference strains from previous work. Aside from the molecular phylogeny, the new cultures are also being studied by microscopic techniques and for their ability to combat other fungi and micro-organisms in dual culture.
Senanayake IC et al. (2015) Towards unraveling relationships in Xylariomycetidae (Sordariomycetes). Fungal Divers 73: 73–144.
Kuhnert E et al. (2015) Lenormandins A – G, new azaphilones from Hypoxylon lenormandii and Hypoxylon jaklitschii sp. nov., recognised by chemotaxonomic data. Fungal Divers 71:165-184.
Kuhnert E et al. (2014) Hypoxyvermelhotins A–C, novel pigments from Hypoxylon lechatii sp. nov. Fungal Biol 118: 242-252
Stadler M et al. (2014) A polyphasic taxonomy of Daldinia (Xylariaceae). Stud Mycol 77: 1-143.
Kuhnert E et al. (2014) New Hypoxylon species from Martinique and new evidence on the molecular phylogeny of Hypoxylon based on ITS rDNA and β-tubulin data. Fungal Divers 64: 181-203.
- Microbial Drugs - Prof. Dr. Marc Stadler
Applications accepted until 31.10.2016
If you are interested to work on one of these projects or something related please contact
Lucile Wendt Lucile.Wendt@helmholtz-hzi.de