S66: Rapid Screening and Dereplication of Marine Symbiotic Natural Products

In this Methods in Natural Products project sponsored by NIGMS, we aimed to develop new methods for the rapid discovery of new natural products. Simultaneously, we were to perform basic studies about symbiosis and natural products in mollusks and tunicates. Here, the Bugni group developed methods to rapidly dereplicate marine bacterial natural products, leading to potently active molecules with novel scaffolds and novel biosynthetic genes. In particular, exceptionally potent antifungals and antibacterials were discovered. The Schmidt group devised new methods for assessing natural products potential of whole marine animals. In doing so, we discovered some fundamental properties of the relationship between symbiosis and natural products biosynthesis. We examined the chemistry and microbiomes of tunicates from tropical, subtropical, and temperate waters. There was no difference in terms of bacterial abundance, richness, or diversity between samples in these different environments, with or without secondary metabolites. Instead, we found that tunicate species with abundant secondary metabolites have a microbiome with a more conserved population structure. This finding can be used to predict the biosynthetic origin of natural products and to discover promising new sources of natural products.