Ethanol production from gas fermentation: Rapid enrichment and domestication of bacterial community with continuous CO/CO_2 gas

摘要

Industrial production processes will produce a large amount of inorganic carbon (CO/CO2), which can be used as a carbon substrate for gaseous fermentation to reduce environmental pollution and promote the development of renewable energy. To solve the bottleneck that the strains used for the gaseous fermentation cannot adapt well to the mixed gas (CO, CO2 and H-2) and the low ethanol production, the mixed gas was aerated continuously into the culture with rabbit faeces to enrich ethanol-producing strains. After CO/CO2 domestication, the structure of the microbial community changed significantly. Blautia, which can use CO/CO2 to produce ethanol, became the dominant bacteria, and the relative abundance significantly increased by 5.4 times to 41.1%. What's more, 14.07% of CO/CO2 was converted to organic carbon through fermentation by the domesticated bacteria, and the ethanol concentration reached 1.41 g L-1. The results indicated that with the continuous CO/CO2 domestication, the bacteria could adapt the syngas better and showed an improved fermentation performance. (C) 2021 Elsevier Ltd. All rights reserved.