USING OMICS APPROACHES TO DECIPHER BACTERIAL AND VIRAL DYNAMICS IN LAKE CHAMPLAIN BEFORE, DURING, AND AFTER A CYANOBACTERIAL HARMFUL ALGAL BLOOM

Lake Champlain is a freshwater lake known for its recreational activities and as a source of drinking water for local communities. However, despite nutrient loading mitigation efforts, cyanobacterial harmful algal blooms (CHABs) in Lake Champlain persist and negatively impact water quality in this aquatic ecosystem. We employed "omics" approaches to better understand the microbial ecology of CHABs. We hypothesized that prokaryotic and viral diversity would vary before, during, and after a bloom event, with decreased overall diversity during the bloom leading to dominant cyanobacteria and cyanophage during the bloom peak; and that toxin-production in key bloom-forming cyanobacteria will be influenced by both physicochemical factors and viral pressures. Viruses, particularly bacteriophage, play important roles in ecosystem nutrient cycling. Our metagenomes and viromes reveal shifts in total community diversity throughout the season, with notable shifts in taxa before, during, and after bloom events. However, the metagenomes suggest that there is a largely stable functional diversity in the metagenomes throughout time. This indicates that although the microbial communities change there is functional redundancy within the ecosystem to allow for continued metabolic processes. Intriguingly, our viromes reveal several genes related to carbon metabolism.

Primary Presenter: Erin Eggleston, Middlebury College (eeggleston@middlebury.edu)

Authors:

Erin Eggleston, Middlebury College  (eeggleston@middlebury.edu)

Irene Hu, Middlebury College  (jiatongh@middlebury.edu)

Isabel Tseng, Middlebury College  (isabel.tseng@childrens.harvard.edu)

Katie Baker, Middlebury College  (katieb@middlebury.edu)

Olwethu Ngubo, Middlebury College  (ongubo@middlebury.edu)

Ana Morales, University of Vermont  (ana.morales@uvm.edu)