Co-culturing to Elicit Chemical Diversity in Fungi - PROJECT SUMMARY
Under standard culture conditions, the profile of the secondary metabolites that fungi are biosynthesizing is
limited to the carbon sources that are in the media. Genomic data from fungi indicate that numerous
biosynthetic gene clusters are silent, and thus, the true chemical potential of a fungal culture is perhaps
unknown, or at least, unobserved. While fungi have a rich history in providing drug leads (such as penicillin),
the discovery of new leads is likely incumbent upon discovering new bioactive molecules. By taking advantage
of the fact that fungi have evolved ways to survive in complex environments, as well as to respond chemically
to different environmental cues, co-culturing is a way to activate the untapped biosynthetic potential of fungi.
The droplet-probe will be used to analyze, in situ, the chemical profiles of secondary metabolites to obtain a
spatial map of how fungi distribute their secondary metabolites during these chemical interactions. Genomics
will be used to link the secondary metabolites produced in co-culture to the producer strain. This study will
triangulate information from biology/mycology (fungal co-culture), metabolomics and genomics (to locate
producer species), and natural products chemistry (isolation and elucidation of new chemistry) to uncover and
activate silent gene clusters to search for unique secondary metabolites. Preliminary data demonstrate that
upon co-culture of fungi, the biosynthesis of secondary metabolites can be stimulated. This is likely because
they interact chemically, essentially fighting for their resources. Xylaria cubensis, a strain that produces the
FDA approved fungistatic drug griseofulvin, will be used as a model organism for co-culturing. Other
endophytic strains, such as Aspergillus sp. and Penicillium sp., will be used along side X. cubensis in the co-
culture experiments, because they produce iconic molecules. In addition, we will target genetically tractable
organisms, since genome studies have shown that members of these genera have rich biosynthetic gene
clusters that produce unknown chemical entities. The mono and co-cultures will undergo untargeted
metabolomics, and PCA will be used to analyze the chemical differences between the mono and co-cultures.
For training, the applicant is part of a natural products chemistry research group as a T32 Fellow in the
Department of Chemistry & Biochemistry at the University of North Carolina at Greensboro. Her skills in that
regard will be further honed via the conduct of Aims 1 and 2. Additionally, so as to further her training, and to
prepare her for a future where genomics will become an even great part of natural products research, she will
receive hands-on training in fungal genomics as part of Aim 3 via close interaction with the research group of
Dr. Antonis Rokas at Vanderbilt University. Finally, to complement her ability to communicate research, she will
receive training in scientific writing, which is currently an underdeveloped skill set of the applicant.