Bioreactor microbiome

Title: Unlocking the bioreactor microbiome for nutrient management and water quality

Location: Ames

Time Period: 2022- 2024

Research Team: Adina Howe, Steven Hall, Michelle Soupir, Jaejin Lee,  Lindsey Hartfiel

Project Description: Bioreactors have been adopted globally to treat nitrate-laden water. Thus far, research has largely focused on understanding the physical and chemical controls of bioreactor performance (system design, temperature, residence time, etc.), showing that regardless of engineering design, nitrate mass removal rate per unit of carbon source is similar across systems. Thus, it is unlikely that engineering design will transform bioreactor performance. Bioreactors are ‘living’ engineered biological systems, and we argue that improvements in their performance will come from design or management of their carbon source and/or microbiomes. For example, among carbon sources, corncobs have high potential for improved NO3-N removal, especially at low temperatures. Corncobs have been shown to have higher NO3-N removals than woodchips. The microbial communities in bioreactors are also pivotal for driving denitrification and “pollution swapping,” namely the production of greenhouse gases (i.e., methane  and nitrous oxide)  and pollutants (i.e., methylmercury).  In this proposal, we seek to identify and manipulate microbial communities in corncob and woodchip bioreactors that mediate complete denitrification of nitrate to dinitrogen gas, with minimal release of nitrous oxide, methane, or methylmercury to expand the full potential of this conservation practice.

Publications:

Funders: Iowa Nutrient Research Center

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