New Publication from the Caesar Lab published in Natural Product Communications

A big congratulations to Ashley and Lexie and the rest of our team for publishing our research in Natural Product Communications!

Our laboratory is very interested in investigating the protective effect of the bat microbiome in preventing the devastating fungal disease "White-nose syndrome" in bat populations. While many researchers have found that bat symbionts have antifungal properties, very few projects have actually sought to identify the bioactive molecules responsible for this activities. With this study, we investigated the antifungal constituents of Streptomyces buecherae, a novel bat-associated bacterium isolated from cave myotis bats in New Mexico.

Integrated Workflow Combining Antifungal Activity Screening Results and Mass Spectral Profiling of Bioactive Bacterial Extracts to Predict Antifungal Compounds for Targeted Study. Created in BioRender. Caesar, L. (2025) https://BioRender.com/z16g949.

Ashley and Lexie worked so hard on this project, and I am so excited to have it finally out in the world! First, they took a bulk extract of 900+ Petri dishes of S. buecherae culture and chromatographically separated them, sent them off for bioactivity screening against P. destructans, and ran the chemical extracts through the mass spectrometer to generate a chemical profile. Instead of continually fractionating and screening the extracts, which can be wasteful and quite time-consuming, we used a methodology called "biochemometrics" to correlate bioactivity results to the chemical data (where fractions often contained hundreds of potentially bioactive compounds), which allowed us to predict the bioactive molecule(s) we wanted to target!

Through this process, we were able to identify a polyether antibiotic called "nigericin" and purchase a standard online. The standard matched our target molecule perfectly, and we then confirmed its biological activity against P. destructans, the fungus that causes white nose syndrome! Now we have a better understanding of how S. buecherae is able to kill P. destructans, which can hopefully translate to its use as a probiotic bacterium for WNS management in the future.

If you'd like to read more, check out our open-access publication here: https://journals.sagepub.com/doi/10.1177/1934578X251376175