Phenotypic Screening and Genome Mining for the Discovery of Natural Products from the Genus Nostoc

The cyanobacterial genus Nostoc has been shown to produce biologically active natural products. Nostoc strains from the UIC cyanobacteria culture collection were investigated for their ability to produce natural products using two complementary approaches to natural product discovery. A phenotypic screening approach was used to identify biologically relevant metabolites. This approach identified a series of knew and known cytotoxic [7,7] paracyclophanes in several cultured Nostoc strains. A genome mining approach facilitated by stable isotopic labeling and comparative metabolomics was used to assess the full natural product producing capabilities of a single strain. This approach identified two new compounds and two known compounds, as well as several new biosynthetic gene clusters in a single Nostoc strain.