Engineered Consortium-Based Biogas Conversion Platforms

The biogas industry continues to expand, driven by technological advances in anaerobic digestion, environmentally conscious practices, and the increasing cost of water and electricity around the world. Before biogas can be used interchangeably with natural gas, however, carbon dioxide and other impurities are often purged in an upgrading process. This process is costly, unsuitable for small-scale or highly distributed digesters, and can contribute to greenhouse gas emissions. The ability to use biogas beyond electricity generation is limited by the high cost, large footprint and inefficiency of chemical conversion technologies. Biological approaches have the potential to convert both the methane and carbon dioxide of biogas directly into liquid products at mild temperatures. Nonetheless, achieving efficient biological biogas conversion will require significant technical advances over the conventional microorganisms, equipment and processes used in industrial biotechnology today. II. Statement of how this problem or situation is being addressed: This project develops a new technology platform specifically designed for high throughput methane and carbon dioxide coconversion using stable microbial consortia. First, the platform enables high control over consortia constituents to enhance metabolite transfer efficiency in the multi-organism pathway. Second, the platform utilizes two strategies to enhance the delivery of key substrates and gases. Finally, stabilizing ecological balances via synthetic biocatalysts will be a key thrust of the project, with an overall goal of producing butanol with both high carbon conversion efficiency and high overall energy efficiency. III. Phase I objectives: This project includes a series of laboratory-scale biochemical and engineering tests to establish the feasibility of the platform, followed by a prototype reactor for integrating the entire bioconversion process. Detailed kinetics studies will be used to evaluate carbon and energy flows in the system to empirically determine these quantitative metrics. Upon successful demonstration of key performance and efficiency parameters, future Phase II work will include the fabrication of a demonstration-scale unit for operation at a digester facility in cooperation with commercial partners. IV. Commercial applications and other benefits: Next-generation consortium-based bioconversion technologies have the potential to mitigate many of the challenges of conventional biological gas conversion technologies, while enabling biogas conversion technologies to become as small and convenient as conventional anaerobic digesters are today. In addition to economic value of the target molecule of this project, butanol, the platform proposed herein can help catalyze the development of key complementary technologies required for the establishment of the biological gas-to-liquids industry. Key words: Biogas, Methane, Greenhouse Gas Emissions, Gas-to-Liquids, Anaerobic Digestion, Biological Conversion, Biofuels, Biobased Chemicals, Materials Science, Microbial Ecology