More than just a fungi? Novel secondary metabolites from marine fungi

Microbes are a rich source of therapeutically useful secondary metabolites. Recently, natural products research was revolutionised by novel techniques combining well-known screening methods with life science informatics strategies. However, this research has primarily focused on terrestrial and marine bacteria, whereas marine fungi have largely been neglected. 

Kumar et al. (2018) applied high-throughput methods to two parasitic fungal isolates, Calcarisporium sp. KF525 and Pestalotiopsis sp. KF079. They sequenced and assembled both genomes, before using bioinformatics tools for genome mining of biosynthetic gene clusters (BGCs). Critically, 98% of the detected BGCs in Calcarisporium sp. and 97% in Pestalotiopsis sp. have no homologous clusters in the relevant database of known BGCs, making them by definition ‘novel’. Some of these BGCs share characteristics with unidentified, bacterial BGCs. This might be due to the fact that the database consists primarily of BGCs found in non-fungal organisms. Although few novel BGCs were expressed in culture, genome mining tools still allowed the authors to make inferences on how the species manage to survive in their host’s environment and how they have specialized for host degradation. However, more importantly, the study emphasizes how little is yet known about BGCs and secondary metabolite biosynthesis in marine fungi and stresses the potential importance of marine fungi in the discovery of novel secondary metabolites and future therapeutic agents.

Kumar, A., Sørensen, J. L., Hansen, F. T., Arvas, M., Syed, M. F., Hassan, L., … Kempken, F. (2018). Genome Sequencing and analyses of Two Marine Fungi from the North Sea Unraveled a Plethora of Novel Biosynthetic Gene Clusters. Scientific Reports, 8(1), 10187. doi: 10.1038/s41598-018-28473-z