Academic Journal
Low electric current in a bioelectrochemical system facilitates ethanol production from CO using CO-enriched mixed culture
| Title: | Low electric current in a bioelectrochemical system facilitates ethanol production from CO using CO-enriched mixed culture |
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| Authors: | Im, Chaeho, 1989, Kim, Minsoo, Kim, Jung Rae, Valgepea, Kaspar, Modin, Oskar, 1980, Nygård, Yvonne, 1986, Franzén, Carl Johan, 1966 |
| Source: | Kartläggning av stress relaterad till jäsning av syngas - mot en effektiv förvandling av CO och Co2 till bioetanol Frontiers in Microbiology. 15 |
| Subject Terms: | acetogen, Clostridium autoethanogenum, bioelectrochemical system, carbon monoxide, gas fermentation, bioethanol, microbial electrosynthesis |
| Description: | Fossil resources must be replaced by renewable resources in production systems to mitigate green-house gas emissions and combat climate change. Electro-fermentation utilizes a bioelectrochemical system (BES) to valorize industrial and municipal waste. Current electro-fermentation research is mainly focused on microbial electrosynthesis using CO2 for producing commodity chemicals and replacing petroleum-based infrastructures. However, slow production rates and low titers of metabolites during CO2-based microbial electrosynthesis impede its implementation to the real application in the near future. On the other hand, CO is a highly reactive gas and an abundant feedstock discharged from fossil fuel-based industry. Here, we investigated CO and CO2 electro-fermentation, using a CO-enriched culture. Fresh cow fecal waste was enriched under an atmosphere of 50% CO and 20% CO2 in N-2 using serial cultivation. The CO-enriched culture was dominated by Clostridium autoethanogenum (>= 89%) and showed electro-activity in a BES reactor with CO2 sparging. When 50% CO was included in the 20% CO2 gas with 10 mA applied current, acetate and ethanol were produced up to 12.9 +/- 2.7 mM and 2.7 +/- 1.1 mM, respectively. The coulombic efficiency was estimated to 148% +/- 8% without an electron mediator. At 25 mA, the culture showed faster initial growth and acetate production but no ethanol production, and only at 86% +/- 4% coulombic efficiency. The maximum optical density (OD) of 10 mA and 25 mA reactors were 0.29 +/- 0.07 and 0.41 +/- 0.03, respectively, whereas it was 0.77 +/- 0.19 without electric current. These results show that CO electro-fermentation at low current can be an alternative way of valorizing industrial waste gas using a bioelectrochemical system. |
| File Description: | electronic |
| Access URL: | https://research.chalmers.se/publication/542904 https://research.chalmers.se/publication/542904/file/542904_Fulltext.pdf |
| Database: | SwePub |
| ISSN: | 1664302x |
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| DOI: | 10.3389/fmicb.2024.1438758 |