Spring 2019

Document Type

Poster Session


Biological Sciences


Rachel Larsen PhD


aquaponics, nitrogren-rich ecosystem


In natural ecosystems, nitrogen-fixing bacteria act as the primary source of useable nitrogen for many plants by converting atmospheric N2 into ammonia. In an aquaponics system, however, the primary source of ammonia is provided by fish waste. We are investigating the effect of this ammonia saturation on the diversity of nitrogen-fixing bacteria in a sample aquaponics system. We seek to answer two fundamental questions: First, what nitrogen fixing microbes are present in these systems? Second, does the character of these microbial communities have any effect on plant growth? In order to answer these questions, we first determine whether nitrogen-fixing bacteria are present in the system by culturing resident bacterial populations on nitrogen-free media, isolating, and identifying these species. We then investigate the diversity of both cultured and non-culturable nitrogen-fixing bacteria via metagenomic analysis. Finally, we will investigate possible links between the characteristics of these microbial communities and plant health.

Start Date

4-19-2019 1:15 PM



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