Kurt, E.; Qin, J.; Williams, A.; Zhao, Y.; Xie, D. Perspectives for Using CO2 as a Feedstock for Biomanufacturing of Fuels and Chemicals. Bioengineering2023, 10, 1357.
Kurt, E.; Qin, J.; Williams, A.; Zhao, Y.; Xie, D. Perspectives for Using CO2 as a Feedstock for Biomanufacturing of Fuels and Chemicals. Bioengineering 2023, 10, 1357.
Kurt, E.; Qin, J.; Williams, A.; Zhao, Y.; Xie, D. Perspectives for Using CO2 as a Feedstock for Biomanufacturing of Fuels and Chemicals. Bioengineering2023, 10, 1357.
Kurt, E.; Qin, J.; Williams, A.; Zhao, Y.; Xie, D. Perspectives for Using CO2 as a Feedstock for Biomanufacturing of Fuels and Chemicals. Bioengineering 2023, 10, 1357.
Abstract
Microbial cell factories offer an eco-friendly alternative for transforming raw materials into commercially valuable products, primarily because of their reduced carbon impact compared to conventional industrial procedures. These systems often depend on lignocellulosic materials, mainly pentose and hexose sugars, richly available carbon reservoirs. Nevertheless, these resources might not always be efficient due to the limited supply, significant cost, and other considerable obstacles. One major hurdle when working with sugars derived from lignocellulosic biomass, especially glucose, is balancing carbon allocation to satisfy energy, cofactor, and other essential component needs for cellular proliferation while maintaining a robust yield. Furthermore, nearly half or more of this carbon is inevitably lost as CO2 during the biosynthesis processes, which serves to generate the energy necessary for maintaining cell growth and other regular metabolic activities. This carbon loss lowers the theoretical production yield and compromises the benefit of reducing greenhouse gas emissions – a fundamental advantage of biomanufacturing. This review paper posits the perspectives of using CO2 from atmosphere, industrial wastes, or the exhausted gases generated in microbial fermentation as a feedstock for biomanufacturing. Both one-step direct CO2 fixation or two-step indirect CO2 fixation and conversion strategies are discussed, which can minimize the carbon loss, significantly increase the carbon yield, and eventually achieve the carbon-neutral or -negative goals. The one-step strategy uses novel metabolic pathway design and engineering approaches to directly fix the CO2 via the pathway toward the synthesis of the desired fermentation products. Due to the limitation of the yield and efficiency in one-step CO2 fixation, the two-step strategy aims to completely avoid carbon loss in biomanufacturing by integrating a first electrochemical fixation of the exhausted CO2 into C1/C2 products such as formate, methanol, acetate, and ethanol and a second fermentation unit to utilize the CO2-derived C1/C2 chemicals or co-utilize both C5/C6 sugars and C1/C2 chemicals for product formation. The great potentials and challenges of using CO2 as a feedstock for further biomanufacturing are also discussed.
Keywords
Metabolic engineering; CO2 fixation; feedstock; biomanufacturing; electrochemical catalysis; microbial electrosynthesis
Subject
Engineering, Bioengineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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