Postdoctoral Fellowship: PRFB: Examining the role of the bivalve gut microbiome in facilitating xenobiotic tolerance

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2025. The fellowship supports research and training of the fellow that will contribute to biology in innovative ways. Many animals rely on gut microbes to break down toxins in their plant-based diet.

In some insects and mammals, this “microbial facilitation” also helps detoxify ingested pesticides and pollutants. Release of human pharmaceuticals into the oceans has raised concerns about toxic effects on filter-feeding organisms like mussels, which cannot escape toxic stress. This research will investigate how the blue mussel Mytilus edulis and its gut microbiome interact to break down a toxic pharmaceutical pollutant.

Understanding how microbial breakdown of pollutants affects mussel health will improve predictions of how bivalves will adapt to more foreign substances in their environment. Detoxifying microbes in the gut could help mussel populations tolerate toxic threats and position microbiome health as a key concern in their conservation and aquaculture. Undergraduate research mentorship and career pathway development constitute key broader impact activities.

The research will involve three major approaches using the pharmaceutical contaminant carbamazepine (CBZ), which accumulates in and is toxic to marine bivalves. Mussels from a CBZ-free habitat will be exposed to a range of CBZ concentrations in microcosms, and the tolerance of the mussel and its gut microbiome (combined “holobiont”) assessed. Next, gut microbiomes of mussels from CBZ-polluted habitats will be diminished with antibiotics, and animals will be exposed to CBZ in the laboratory.

This approach will demonstrate to what degree a functioning, healthy microbiome assists in CBZ detoxification, and implications of disturbing this microbiome on the health of the mussel under CBZ stress. Lastly, the fellow will investigate how simulated predation stress in mussels from CBZ-polluted habitats could affect the holobiont’s susceptibility to CBZ toxicity.

Molecular and physiological markers will be used to assess mussel health, and DNA and RNA sequencing of the gut microbial community will be used to identify taxonomic shifts, detect functional responses to CBZ, and recover genomes of potential CBZ-degrading microbes. Research and training activities will contribute to a more comprehensive understanding of bivalve health and resilience in polluted environments.

The fellow will engage NSF-funded Research Experiences for Undergraduates interns in the research and collaborate with the Connecticut National Estuarine Research Reserve to develop technical competencies in next-generation sequencing for conservation efforts among Reserve interns.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.