Exploring a Sponge-Derived Leucobacter sp. as a Potential Source for Antibiotics

Abstract

Antibiotic resistance is a rising global health concern. Many of the current antibiotics produced by microorganisms are derived from well researched bacteria such as the genus Streptomyces. Though Streptomyces is a remarkable source of potential therapeutics and should be continued to be studied, studying predominantly this genus limits the diversity of chemical structures and scaffolds to be discovered. This urges a call to diversify the bacteria currently being studied to produce or inspire novel natural product scaffolds. In the current study, we isolated a Leucobacter sp. from a freshwater sponge in the Apostle Islands which was grown on a large scale and the secondary metabolites were extracted for compound isolation and characterization. As an understudied bacterial genus, which it is characterized as a genus with fewer than five papers that report a secondary metabolite, Leucobacter sp. has the potential to offer unique chemical scaffolds. Utilizing spectrometric techniques, we were able to dereplicate the secondary metabolites extracted using the DEREPLICATOR tool available on GNPS, which indicating no known antibiotics present. This suggests that there could be new antibacterial secondary metabolites that have not previously been discovered or studied. Analyzed LC/MS q-TOF data shows a molecule with the MW of 1268 m/z. HPLC and NMR spectroscopy experiments are currently in progress to isolate and characterize this compound and others present in the extract. We hope to obtain bioactivity data once isolation and characterizitaion is accomplished. This study into the Leucobacter isolate could exhibit new chemical spaces and broaden our knowledge of secondary metabolites and novel scaffolds derived from the Leucobacter sp. that can be used in the fight against antibiotic resistance.