Researcher(s)
- Andrew Dalton, Chemical Engineering, University of Delaware
- Joseph Dougherty, Chemical Engineering, University of Delaware
Faculty Mentor(s)
- Eleftherios Papoutsakis, Chemical and Biomolecular Engineering, University of Delaware
Abstract
The urgent need to reduce fossil fuel dependency has sparked the emergence of a bio-based economy, with microbes playing a crucial role in bioenergy production. The global biofuels market size is estimated to grow at a compound annual growth rate of 11.1% between 2023 to 2030, underlining the shift movement towards more sustainable industrial practices worldwide. Clostridium organisms are a set of microbes with much importance in the development of the production of biofuels and bio-derived commodity chemicals. They are uniquely capable in the ability to perform fermentation on a large variety of substrates, including biomass derived carbohydrates, waste gasses, waste materials, C1 materials, and produce a variety of metabolites varying from C4-C8 chain lengths. An engineered mixotrophic consortium of species such as Clostridium acetobutylicum and Clostridium ljungdahlii allows the combination of acetogenic and solventogenic species capable of outperforming monocultures in producing compounds such as Isopropanol, Butanol, Ethanol, and Acetone (IBEA). The goal of this work is to develop and optimize bioreactor operation in order to improve the efficiency of these fermentations while enhancing CO2 fixation in order to create a greener process. In a recent 48 hour coculture fermentation we produced 0.851 g/L/h of IBEA with a 74% yield, showing improvement compared to our previous experiments, as well as in comparison with similar microbial fermentations found in the literature. Despite this achievement, our work is actively ongoing with plans to further enhance this process by promoting better C. ljungdahlii health to produce more isopropanol with higher CO2 fixation, as well as incorporating gas recycling, and methods of cell retention.