Unlocking the bioreactor microbiome for nutrient management and water quality

Issue

Currently, the bioreactor microbial community is a black box of uncertainty in terms of what is responsible for the denitrification and pollution swapping and where the community is originating from. Preliminary data from researchers’ prior work compared woodchips from nine field bioreactors operating for two years at different flow conditions and identified consistent microbial membership between the installed bioreactors as well as consistent load reduction across the range of controlled hydraulic retention times. These observations, that predictable microbes were associated with bioreactors with varied engineered controls, are the rationale for the hypothesis that bioreactor microbiomes can be selected and may also be managed. Researchers believe that understanding how the environmental conditions affect both nutrient removal and the microbiome will benefit bioreactor performance and ensure the sustainability of their operations.

Objective

In this proposal, researchers 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. Further, treating bioreactor microbial communities as manageable resources, they will evaluate the feasibility of managing and manipulating bioreactor microbiomes to benefit bioreactor performance.  

Approach

The researchers will use the data collected to develop a model, which will be the first to link operation, microbiome and function, and will support understanding of the underlying biological and chemical controls for integrating this conservation practice in agroecosystems.