Antibacterial Screening of Aquatic Fungal Isolates

Fungi have played a significant role in human history and continue to hold immense potential in producing new medicines. A recent large-scale analysis of fungal genomes revealed 12,000 previously uncharacterized biosynthetic gene cluster families, indicating that fungi are a rich, largely untapped resource for novel bioactive compounds (Robey et al., PNAS 2021). The Carlson Lab Fungal Library consists of 100 unique fungal isolates collected from diverse aquatic environments, characterized by their morphology, growth rates, and spore coverage patterns. We aim to explore the antibacterial properties of these aquatic fungal strains. Fungi are isolated by serial plating on potato dextrose agarose (PDA) to obtain single morphology isolate plates. The fungi is then inoculated in 25 mL of potato dextrose broth (PDB), before being placed on the rotary shaker at 80 rpm for 3–7 days. The hyphae is weighed and lysed with liquid nitrogen and undergoes genomic DNA extraction using the Qiagen DNeasy Plant Pro kit. Ethyl acetate is added to the remaining culture media and shaken overnight. The extract is then dried using a rotary evaporator, diluted with dimethyl sulfoxide (DMSO) to 10 mg/mL, and added to the chemical fungi library. The fungal library is then characterized by High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography-Mass Spectrometry (LCMS) to generate chemical profiles. Our goal is to explore the antibacterial potential of fungal isolates, ultimately contributing to the broader understanding of fungi as a potential source for novel antimicrobial agents.