Unlocking the bioreactor microbiome for nutrient management and water quality

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. 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.

Collaborators

Michelle Soupir, ISU Jaejin Lee, ISU Steven Hall, University of Wisconsin - Madison

Funding

Iowa Nutrient Reduction Center