Publication Details |
| Category | Text Publication |
| Reference Category | Preprints |
| DOI | 10.1101/2025.10.16.682809 |
Licence  |
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| Title (Primary) | Reduced carbon emissions and chain elongation during mixotrophic fermentation of a biomass feedstock |
| Author | Afzal, M.X.; Bonatelli, M.L.; Kleinsteuber, S.
; Sträuber, H.; Baleeiro, F.C.F. |
| Source Titel | bioRxiv |
| Year | 2025 |
| Department | MIBITECH |
| Language | englisch |
| Topic | T7 Bioeconomy |
| Abstract | Anaerobic fermentation of biomass feedstocks using open cultures is a promising technology to produce platform carboxylates. Syngas, a mixture of H2, CO2, and CO, can be sourced sustainably and used to supplement biomass feedstocks as a source of acetyl-CoA, an intermediate for carboxylate chain elongation. To test this, syngas and corn silage were provided to a 10-L semi-continuous fermenter for 209 days of operation in a first-of-a-kind study at this scale. After acclimation to syngas, a two-fold reduction in average CO2 production rate (0.097 vs. 0.21 g L-1d-1) was observed over a period of 42 days in comparison to a control. Syngas co-feeding also increased average production rates of n-butyrate (C4) and n-caproate (C6) by 74% and 27%, respectively, although these effects were observed at relatively low C6 concentrations up to 4 g L-1. Relative abundances of Megasphaera and Dialister showed significant correlation (p<0.05) to consumption of H2 and CO as well as production of C4 and C6, suggesting involvement of these genera in mixotrophic metabolism. A feasibility analysis showed that syngas recirculation could return additional 1.54 USD m-3broth while costing 1.26 USD m-3broth and avoiding 1.81 kg CO2 eq. m-3broth in emissions compared to heterotrophic fermentation. We propose mixotrophic fermentation as a ‘low-tech’ technology to turn fermenters into decentralized industrial carbon sinks. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=31521 |
| Afzal, M.X., Bonatelli, M.L., Kleinsteuber, S., Sträuber, H., Baleeiro, F.C.F. (2025): Reduced carbon emissions and chain elongation during mixotrophic fermentation of a biomass feedstock bioRxiv 10.1101/2025.10.16.682809 |
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