Principal Investigator Gregory Stephanopoulos
Cellulose, a renewable material found in abundance across the plant taxa, makes up a large portion of municipal solid waste in the form of paper/packaging materials. The overall aim of our project is to utilize cellulosic waste materials as substrate in model microbial fuel cells (MFCs) in order to produce an effective bioreduction system that can (i) generate electricity and (ii) treat recalcitrant pollutants in industrial wastewater and contaminated groundwater.
Evaluate and optimize biological cellulolytic, fermentative, and extracellular electron transfer processes to efficiently produce steady and controllable levels of reducing equivalents from cellulose substrate in pure-culture model MFCs.
Impact on Global Sustainability(*) Create novel biological processes that use renewable materials for electricity generation and contaminated water treatment.(*) Generate new knowledge in the area of applied biotechnology, in particular, analysis methodologies and optimization strategies for pure culture MFCs.
MFCs are low-temperature waste-to-energy systems that have to date mostly been used to demonstrate limited power generation, typically in the range of unit kWh/d, from municipal wastewater and soluble sugar substrates. This project marks a departure from conventional MFC research by shifting from low-strength soluble substrates to high-strength wastes (e.g., biopolymers) in order to enhance total energetic output by allowing sustained operation of the MFC in batch mode. The project is also novel because it uses pure culture MFCs instead of the commonly used mixed culture MFCs. This facilitates the application of metabolic flux analysis tools, which can create highly controlled model systems for better MFC system optimization and control.
A survey of the literature relevant to pure culture MFCs materials and measurement techniques was completed. Following the initial literature survey, an initial set of pure-culture autoclavable MFCs were designed and fabricated in polymeric materials and in glass. In addition to this, brush anodes were designed and fabricated using carbon fiber and titanium wire. Testing of different anodes, cathodes, and membrane-electrode assemblies with biological cultures is poised to begin in the near future. Manuscript of a review paper dealing with biopolymer use in MFCs is currently under preparation.