Morgan Gilboe
Research Mentor(s): Erik Kiledal
Mentor Department: Earth and Environmental Sciences
Authors: Morgan Gilboe, Anders Kiledal
Session: Session 5 (2:00pm – 2:50pm)
Presentation Type: Oral
Abstract
Lake Erie experiences annual harmful algal blooms (HABs) dominated by the cyanobacterium Microcystis, which can produce the hepatotoxin microcystin, posing risks to both ecosystems and public health. The Microcystis microbiome, composed of associated heterotrophic bacteria, plays a crucial role in nutrient cycling, bloom development, and biomass degradation. However, the extent and mechanisms of these interactions remain poorly understood. This project investigates cross-feeding, metabolic exchanges, and microcystin degradation within the Microcystis microbiome to better understand these ecological relationships. Since 2022, we have isolated over 130 heterotrophic bacterial strains from western Lake Erie blooms and selected five representative genera (Brevundimonas, Bosea, Curvibacter, Alterethyrobacter, and Roseomonas) for whole-genome sequencing. Additionally, we analyzed Microcystis genomes and shotgun metagenomic data from bloom samples to characterize metabolic interactions. Using genome-scale metabolic models (GEMs), we identified potential metabolic overlap, nutrient exchange, and competitive interactions between Microcystis and its associated bacteria. We also screened for mlr genes linked to microcystin degradation, with future experiments planned to validate these predictions. By integrating genomic, metagenomic, and computational modeling approaches, this research provides insights into the functional role of heterotrophic bacteria in Microcystis blooms. A deeper understanding of these microbial interactions could help refine HAB management strategies and contribute to ecologically based approaches for mitigating microcystin contamination in Lake Erie and other freshwater systems.
