Abstract: Microbial bioprocesses are a cornerstone of our urban water quality control infrastructure. They are also increasingly viewed as a crucial platform in the emerging circular bioeconomy to recover valuable resources (clean water, energy, nutrients, bio-based chemicals) from carbon and nutrient rich societal waste streams. Despite their environmental and economic importance, surprisingly little is known about the nature or "design rules" of the complex microbial communities that underlie emergent function in these bioprocesses. In this talk, I will detail our efforts to deepen understanding of diversity and metabolic versatility in the microbial world in order to inspire novel decarbonized environmental bioprocesses, with a particular focus on nitrogen (N) and phosphorus (P) recovery. Our efforts address the grand challenge of preventing nutrient pollution responsible for a vast array of environmental and public health problems, including eutrophication of water bodies, greenhouse gas (nitrous oxide, N2O) production, and direct adverse effects to human health. First, I will introduce an emerging paradigm in which societal waste streams are viewed not as costly energy sinks but as feedstocks for energy or resource recovery. Next, I will detail our efforts to identify and address key barriers to nutrient recovery and to expand the product portfolio for N recovery. I will then highlight cyanophycin, an underexplored N-rich microbial biopolymer, as a promising target for N recovery. Finally, I will present a novel bioprocess for microbial production and capture of N2O as a source of bioenergy, with concurrent recovery of P as a fertilizer. Meta-omic analyses of the underlying bioprocess microbiome revealed a surprisingly high prevalence of incomplete denitrification pathways, with far reaching implications for understanding microbial N2O production and metabolic division of labor in engineered and natural systems. Taken together, our results demonstrate the utility of coupling fundamental microbial ecology research to novel environmental bioprocess development.

Bio: George Wells is an Associate Professor in the Department of Civil and Environmental Engineering at Northwestern University, where he directs the Environmental Biotechnology and Microbial Ecology Laboratory. The goal of his research is to deepen fundamental knowledge of the structure and function of microbial communities to inspire innovations in ecological and public health protection and resource recovery. Primary research thrusts in his research program include energy and nutrient recovery from wastewater and other urban "waste" streams, microbial nitrogen and phosphorus cycling, microbial greenhouse gas production, biofilms and biofilm reactors, and microbial ecology of engineered and impacted aquatic systems. His approach to these research thrusts involves an interdisciplinary integration of environmental bioprocess modeling, development, and testing; cutting-edge microscopy and molecular biology ('omics') tools; ecological theory; and classical microbiology techniques. George received his B.S. in Chemical Engineering and B.A. in Environmental Engineering from Rice University in 2004, and MS (2006) and PhD (2011) in Environmental Engineering at Stanford University. He subsequently was a postdoctoral scholar at EAWAG before joining Northwestern in 2013. George has authored >85 peer reviewed journal articles and serves on the leadership committees of the International Water Association (IWA) Microbial Ecology and Water Engineering Specialist Group and the IWA Nutrient Removal and Recovery Specialist Group. He also serves on the editorial boards of Frontiers in Microbiology, Resources, Conservation, and Recycling, and Microbial Biotechnology.