(563a) Investigation of Unique Interspecies Interactions in a Synthetic and Syntrophic Clostridium Co-Culture
AIChE Annual Meeting
Wednesday, October 31, 2018 - 3:30pm to 3:48pm
Kamil Charubin1,2, and E. Terry Papoutsakis1,2,3
1 Department of Chemical and Biomolecular Engineering, University of Delaware, Newark DE.
2 Delaware Biotechnology Institute, Newark DE.
3 Department of Biological Sciences, University of Delaware, Newark DE.
In microbial fermentations at least 33% of the sugar substrate is lost as CO2 waste during the pyruvate decarboxylation, with the corresponding loss of electrons in the form of H2. To improve fermentation efficiencies we designed a synthetic and syntrophic co-culture of Clostridium acetobutylicum, which is capable of converting a variety of sugars into solvents, and C. ljungdahlii, an acetogen capable of fixing CO2 in the presence of H2. The co-culture was found to reach higher carbon recoveries and produce non-native products i.e. isopropanol and 2,3-butanediol. The physical contact between both strains was found to be crucial in maintaining the unique co-culture phenotype. The interspecies interaction led to a metabolite exchange, which allowed for the generation of non-native products, and a differential gene expression of the key enzymes in the co-culture. To investigate the interspecies interaction between C. acetobutylicum and C. ljungdahlii more closely we first engineered a fluorescent C. acetobutylicum strain that does not require O2 for fluorophore activation. In combination with fluorescent dyes, correlative confocal and electron microscopy was used to study the timeframe and the extent of interactions between both strains in the co-culture.
SUPPORTED by the National Science Foundation through the NSF grant (Award No. CBET-1511660) and the IGERT fellowship (Award No. 1144726), and the Army Research Office (Award No. W911NF-17-1-0343).