BRITE Pivot: Growing Biological Methods to Improve Soil Behavior for Infrastructure Protection

This Boosting Research Ideas for Transformative and Equitable Advances in Engineering (BRITE) Pivot project will focus on exploring natural soil microbes that can be harnessed to improve soil supporting civil infrastructure. The performance of civil infrastructure is often limited by soft, loose, and/or collapsible soil conditions. These issues are exacerbated by global climate changes as additional stresses are imposed on our infrastructure. Therefore, innovative methods are needed to support new or rehabilitated civil infrastructure, and soil microbes may help address this issue. Microbes naturally alter the subsurface, changing sand to sandstone over geologic time; they also have the potential to create these changes over engineering time frames. In order to use microbes as a natural, sustainable method to improve soft soil, better understanding of the complex microbial communities in the soil is needed. The outcomes of this work will advance the field of bio-mediated soil improvement by characterizing soil microbial communities and exploring methods to harness their natural processes to enhance soil behavior. The microbial processes may also provide insight on mechanisms to capture carbon dioxide into the soil. This may lead to the development of a soil improvement method that can support infrastructure and sequester carbon dioxide, which would provide a substantial benefit to society by simultaneously addressing climate change and our aging infrastructure. The overarching research question is, “Can we understand processes in existing microbial communities well enough to harness them for soil improvement applications?” The research question will be addressed by first identifying the active microbial communities within relevant soil microcosms, and then by manipulating the geochemistry of the microcosms to induce relevant microbial byproducts, such as mineral precipitation or gas generation. An integrated meta-omic approach will address the research question and develop a framework for site-specific bio-mediated soil improvement; therefore, a pivot into meta-omics is needed. The pivot will be accomplished through training in meta-omic approaches within a microbial ecology-focused laboratory. The meta-omic approaches will be applied to various relevant soil microcosms, coupled with physiological incubation experiments. The ability of the identified indigenous microbial communities to improve soil properties will be assessed through experiments and geotechnical testing (i.e., geophysical methods, triaxial and/or simple shear tests, and oedometer tests). This work has the potential to bring about a new paradigm for infrastructure support with the development of site-specific bio-mediated soil improvement. Furthermore, the explored biological mechanisms could provide mechanisms that not only reinforce the soil through carbonate precipitation but also capture atmospheric carbon dioxide and sequester it into the subsurface. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.