Kate Philips

In recent years, the gap between human diseases and available pharmaceutical treatments has made increasingly evident the need for new therapeutics. Natural products are one source for novel drugs. Historically, microbial natural products were discovered through an untargeted process of culturing and fermentation, after which cellular extracts were analyzed for unique and interesting functions. However, there are several problems with this approach. First, without a targeted product, rediscovery of molecules is a problem. Second, natural products are typically not synthesized unless environmental conditions call for their production. The genomics era offered solutions to these problems with the advent of sequencing and bioinformatics technologies. These advancements allow identification of biosynthetic gene clusters (BGCs), clusters of genes thought to be involved in the production and management of natural products, and allow prediction of the class of molecule the BGC is responsible for. Genetic engineering techniques are used to pare a BGC down to only synthetic genes and replace endogenous promoters with constitutively “on” promoters. In this way, sequencing and function predictions limit rediscovery and editing ensures targeted product synthesis regardless of environmental conditions prior to culturing and fermentation. In this project, I report a genomics-based approach for the engineering of a novel terpene BGC in Streptomyces bacteria and subsequent characterization of the molecule. Liquid chromatography-mass spectrometry (LC-MS) data show the production of several new molecules in the BGC strain that are not produced in the control strain. Of note, two uncharacterized ions of masses 357.106 and 390.271 m/z were detected in positive mode LC-MS and one uncharacterized ion of mass 405.264 m/z was detected in negative mode LC-MS.