The proposed research deals with engineering strategies to improve biobutanol production from low-cost, bacteria-based biomass technologies.
This project seeks to achieve high-titer and high-yield butanol production by the bacterium Clostridium tyrobutyricum. Particularly, an innovative engineering approach, i.e., Metabolic Cell-Process Engineering (MCPE), will be developed to substantially increase biobutanol production through understanding the interaction between a host cell and its fermentation process. Specifically, it is planned to: 1) Develop a fundamental understanding of the response of a recently metabolically engineered C. tyrobutyricum mutant cell to various chemicals (e.g., electron carriers and inorganic salts), and identify cost effective chemicals to boost the NADH (Reduced Nicotinamide Adenine Dinucleotide) pool and detoxify the inhibitors from biomass hydrolysate. A Design of Experiment (DOE) approach will be used to screen and identify the chemicals needed for redox balance and detoxification. 2) Double butanol production via MCPE by increasing intracellular NADH and reducing the toxicity of biomass hydrolysate. The construction of a novel redox engineered mutant (MCE) and development of fermentation process with timed addition of the identified chemicals (MPE) will be integrated and utilized in butanol production.
Broader Significance and Importance:
Butanol is an important industrial solvent and a safe alternative transportation fuel that can be dispersed through existing pipelines and filling stations. Over the past decades, intensive efforts have been made to produce low-cost biobutanol using low-value biomass. However, biobutanol production still suffers from low yields and effective concentrations due to a variety of chemical issues associated with existing processes. The proposed MCPE engineering strategy has the potential to double biobutanol production, at a projected cost under $2.5 per gallon. Therefore, successfully developing the proposed technology can serve the public interest by providing a safe, renewable energy source while protecting natural resources and the environment. Many bioenergy industries and other areas of academic research would benefit from the development of novel engineering strain using MCPE.
Broadening Participation of Underrepresented Groups in Engineering:
This project also aims to broaden the participation of underrepresented groups and increase diversity. The Department of Chemical and Biological Engineering (ChBE) with over 600 undergraduates has historically attracted about 40 % women and more than 60 % of the students are interested in Biotech industry and graduate programs. Therefore, it is very important to enhance the ChBE curriculum by taking advantage of the unique 6-year Biotech industrial experiences of the PI. Specifically, a serial of bioproduction unit operations (e.g. novel bioreactor design and biobutanol fermentation demo run) will be designed and introduced to the traditional ChBE 319 Unit Operation Lab course. These new features can expand the students' knowledge of industry bioproduction and benefit their career goal development. Suitable biochemical reaction and titration experiments and guest lectures will be introduced to K-12 students through Alabama Science in Motion (ASIM) that covers 9 counties in west Alabama, including the impoverish Black Belt area. Outreach activities such as recruiting women researchers through SWE and REU and mentoring them in PI lab are also planned.
This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.
