SBIR Phase I: Metabolic Engineering for Clostridial Biotechnology

This Small Business Innovation Research Phase I project aims to develop platform clostridia strains suitable for industrial scale alcohol production from renewable feedstocks and also to improve metabolic engineering technologies for all clostridia. Clostridia are strictly anaerobic, endospore forming prokaryotes of major importance to cellulose degradation, human and animal health and physiology, anaerobic degradation of simple and complex carbohydrates. Obstacles for the industrial use of these organisms include the development of genetic and metabolic engineering tools and strategies that could lead to strains suitable for production of chemicals and fuels from renewable feedstocks. This project focuses on developing metabolic engineering strategies and strains of solventogenic clostridia for the production of chemicals and biofuels. Through novel approaches, this project aims to solve three important bioprocessing bottlenecks: 1) product formation characteristics, 2) product yield and selectivity, 3) and suitable characteristics for repeated fed-batch or continuous fermentations. Anticipated outcomes of this project are clostridia strains that overcome the aforementioned bioprocessing bottlenecks and improved metabolic engineering technologies that are applicable to all clostridia. Development of biorefinery and biofuel technologies has been on the scientific and technological agenda of our nation for over 35 years now but never quite with the urgency of the last 2-3 years. Oil supplies for producing chemicals and fuels are becoming increasingly limiting and unreliable. Moreover, use or combustion of non-renewable chemicals and fuels detrimentally impacts the climate of our planet. Biomass is a carbon-neutral renewable resource for producing chemicals and fuels and the basis for the biorefinery concept. Solventogenic, butyric-acid clostridia played a major industrial role in the production of acetone and butanol in the past. Metabolic engineering of solventogenic clostridia may lead to industrial processes for production of chemicals such as butyric acid, butanol, butanediol, propanol, and acetoin, and production of hydrogen. Some of these chemicals can serve as biofuels directly, while others can be used for chemical conversion to biofuels. A major advantage of these organisms is that they can directly ferment a large spectrum of simple and complex carbohydrates including lignocellulosics with minimal pretreatment. The commercial potential of metabolically engineered solventogenic clostridia is exceptional but remains largely unexplored. This project aims to capture and demonstrate part of this potential. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).