Isolation and Characterization of Antimicrobials from Icelandic Aquatic Bacteria

Abstract

Since the Golden Age of natural product (NP) antibiotic discovery in the mid‐1950s, NP discovery has declined despite methodological advances. As a result, antibacterial discovery is being outpaced by antibiotic resistance. One significant challenge in antibiotic discovery is the rediscovery of antibiotic compounds previously isolated from bacteria. Generating a diverse microbial library can help overcome the rediscovery of antibiotic compounds, but major challenges to this approach include the inefficiency of commonly used methods to create high‐throughput libraries of bacteria and the difficulty of reducing redundancy within these libraries. To combat these issues, the Murphy lab works with an innovative NP discovery using IDBac, an efficient, rapid process developed to reduce taxonomic and chemical redundancy in microbial libraries. In the current study, we performed liquid chromatographic separations of Icelandic bacterial isolates K391, K765, and K802. We then investigated each isolate's antibacterial ability against pathogens through growth inhibition assays. Bacterial isolate K391 displayed weak antibacterial activity in fractions 3‐5, 14‐15, and 25‐26 and showed presence of a small molecule, which may hold potential as an antibiotic via MS/MS peaks from fractions 14‐15. We are further investigating the K391 fractions through GNPS analysis and running liquid chromatographic separations of K765 and K802 in normal phase.