Probing the Natural Product Biosynthetic Potential of Actinomycetes Actinosynnema mirum and Streptosporangium roseum

Natural products are organic molecules made by various organisms which often possess bioactivities that make them useful as drugs, drug leads, or probes for deciphering biological networks. Recent sequencing of hundreds of new bacterial genomes and development of advanced bioinformatics tools has made it possible to identify prolific natural product producing bacteria not previously known to produce these compounds. Our research focuses two Actinobateria, Actinosynnema mirum and Streptosporangium roseum.  We are using bioinformatics tools developed in the Melançon lab and elsewhere, such as Bioextract and antiSMASH, to identify and annotate all natural product gene clusters in the genomes of these organisms, and predict the structures and molecular weights of the encoded compounds. We have also designed real time PCR primers against two genes in one natural product gene cluster in A. mirum to determine if the cluster is transcriptionally active. This real time PCR-based approach will be extended to other natural product gene clusters in A. mirum and S. roseum to get a more global view of regulation of natural product biosynthesis in these organisms.  We cultured these organisms on a large scale and obtained crude natural product extracts using standard isolation techniques, including organic extraction and adsorption onto Amberlite XAD-7 and XAD-16 resins.  These extracts will be analyzed for predicted natural products using analytical HPLC-ESI mass spectrometry.  Compounds of interest will be purified using preparative HPLC, their structures determined by NMR, and their antibacterial and anticancer activities assessed by our group and collaborators at UNMHSC.