Master of Science
Meredith Protas, PhD
Shayin Gottlieb, PhD
Bridget Hansen, PhD
Diazotrophs increase plant productivity by providing ammonia directly to plants in the rhizosphere or through association with the roots (Sun et al., 2021). Leveraging diazotrophs can aid in the reduction or application of harmful synthetic nitrogen fertilizers. This thesis aims to use plant root proteins, or lectins, to more rapidly recover viable diazotrophs that are likely to associate with crops. In this study, lectins, are used to recover bacteria from bulk soil by taking advantage of the binding relationship between lectins and bacterial cell surface polysaccharides. When commercially-available lectins were used with a magnetic pulldown to separate the lectin, bacterial complex from soil, a different community of bacteria was selected in comparison to the native soil population. The lectin assay recovered species from Classes known to contain diazotrophs and other nutrient cyclers such as: Actinobacteria, Alphaproteobacteria, Bacilli, Betaproteobacteria, Chloroflexia, Cytophagia, Deltaproteobacteria, Gammapoteobacteria, and Sphingobacteriia.
Available for download on Friday, May 29, 2026