Collaborative Research: PurSUiT: The diversity and evolution of extremophilic microbial eukaryotes

Microorganisms live in some of the harshest environments on Earth, from glaciers to arid deserts to the geothermal springs that are the focus of this work. Previous work in geothermal environments has led to the discovery of major groups of bacteria and archaea that have unique adaptations to cope with harsh environmental conditions. Single-celled microbial eukaryotes (e.g. protists) remain underexplored in geothermal springs despite evidence that they can be diverse and abundant in these extreme habitats. This research project will document the biodiversity of microbial eukaryotes across geographically and geochemically diverse spring systems and describe new species of microbial eukaryotes. Findings from this research will enable more accurate estimates of species diversity and expand our understanding of the diversity of eukaryotes. Broad interest in geothermal systems will also be leveraged to increase participation by undergraduate researchers, train the next generation of protistologists, and broaden public understanding of the microbial eukaryotes. The biodiversity of microbial eukaryotes in geothermal springs remains poorly understood as most lineages are only known from environmental sequencing. Single-cell technologies and new culturing approaches coupled with bioinformatics pipelines enables description of the diversity of protists in these extreme environments. This research focuses on two major clades of eukaryotes –Amoebozoa and Heterolobosea – that collectively represent a substantial portion of amoeba diversity and can be abundant in high temperature and low pH environments. Combining single-cell profiling, culturing, and microscopy-based analyses, this project will infer species boundaries, describe new species, and improve reconstructions of the tree of life. Gene families will be analyzed to shed light on putative adaptations that allow survival in extreme environments. Integration of project data will be coordinated with public biodiversity databases and strain collections to enhance access to microbial resources. A summer training workshop will aid in training early career protistologists in the characterization of unknown protist lineages, with modules focused on biodiversity, species discovery, and systematics. A microbial diversity workshop for high school science teachers will provide a foundation on the tree of life and the phylogenetic diversity of eukaryotes. 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.