Detecting co-cultivation induced chemical diversity via 2D NMR fingerprints

Rediscovery of already known compounds is a major issue in microbial natural product drug discovery. In recent years, progress has been made in developing more efficient analytical approaches that quickly identify known compounds in a sample to minimise rediscovery. In parallel, whole genome sequencing of microorganisms has revealed their immense potential to produce secondary metabolites, yet the majority of biosynthetic genes remain silent under common laboratory culturing conditions. Therefore, increased research has focused on optimising culturing methods to activate the silent biosynthetic gene clusters. Co-cultivation of different microbial strains can activate biosynthetic gene clusters that remain silent under standard laboratory fermentations involving mono-cultures, hence, the technique has great potential for natural product drug discovery. However, innovative methods are still needed to evaluate the success of any cocultured fermentation end-product. Here, the application of HSQC-TOCSY NMR spectra and subsequent PCoA to identify changes in the metabolite diversity induced through co-cultivation is described.