NSF Postdoctoral Fellowship in Biology: Free-Living Amoebae Predation Mechanisms and Fostering Inclusive Communities in Environmental Microbiology through Peer-Mentoring

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Broadening Participation of Groups Underrepresented in Biology. Free-living amoebae are single-celled microorganisms that feed on smaller microorganisms, including bacteria, fungi, and viruses. Free-living amoebae are important predators in soil and aquatic ecosystems, influencing microbial communities and contributing to the evolution of bacterial strategies to evade predation. However, the mechanisms that govern interactions between free-living amoebae and bacteria are poorly understood. This research will investigate how free-living amoebae interact with pathogenic and benign bacteria, and how these interactions shape microbial communities. The research is important because it will provide insights essential for engineering of microbial communities and prevention of pathogen growth in soil and aquatic environments. The fellow will broaden participation of groups underrepresented in biology through the formation of a postdoctoral peer mentoring group, which will encourage the retention of postdoctoral researchers from underrepresented groups in science by providing a venue for peer support and professional development. This research will investigate how the ubiquitous free-living amoeba Acanthamoeba castellanii interacts with diverse bacteria, and the resulting impacts on microbial communities. Specific hypotheses include the following: 1) A. castellanii utilizes distinct predation mechanisms for different bacteria, 2) A. castellanii preferentially grazes on benign bacteria versus pathogenic bacteria, 3) chemotaxis is not involved in A. castellanii predation, and 4) predation mechanisms employed by A. castellanii for grazing on bacteria in biofilms are distinct from those used for grazing on planktonic cells. Hypotheses will be investigated using transcriptomics, advanced microscopy, and microfluidic chips with live-cell microscopy. The research will provide vital knowledge regarding predator-prey theory and the interactions between amoebae and bacteria in environmental systems. It also will inform the fields of environmental engineering and public health, which require a deeper understanding of microeukaryotes to effectively control microbial communities and prevent pathogen proliferation. The fellow will receive mentoring in analysis of transcriptomic data sets and live-cell microscopy through the sponsoring scientists. The fellow will also work to broaden the participation of underrepresented groups in biology through mentorship of undergraduate and graduate students in the laboratory and the formation of an interdisciplinary postdoctoral peer mentoring group, which will provide professional development and increase a sense of belonging. 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.