Background: Autotrophic carbon fixation is the primary route through which organic carbon enters the biosphere, and it is a key step in the biogeochemical carbon cycle. The Calvin–Benson–Bassham pathway, which is predominantly found in plants, algae, and some bacteria (mainly cyanobacteria), was previously considered to be the sole carbon-fixation pathway. However, the discovery of a new carbon-fixation pathway in sulfurous green bacteria almost two decades ago encouraged further research on previously overlooked ancient carbon-fixation pathways in taxonomically and phylogenetically distinct microorganisms. Aim of Review: In this review, we summarize the six known natural carbon-fixation pathways and outline the newly proposed additions to this list. We also discuss the recent achievements in synthetic carbon fixation and the importance of the metabolism of thermophilic microorganisms in this field. Key Scientific Concepts of Review: Currently, at least six carbon-fixation routes have been confirmed in Bacteria and Archaea. Other possible candidate routes have also been suggested on the basis of emerging “omics” data analyses, expanding our knowledge and stimulating discussions on the importance of these pathways in the way organisms acquire carbon. Notably, the currently known natural fixation routes cannot balance the excessive anthropogenic carbon emissions in a highly unbalanced global carbon cycle. Therefore, significant efforts have also been made to improve the existing carbon-fixation pathways and/or design new efficient in vitro and in vivo synthetic pathways.
Bibliographical noteKAUST Repository Item: Exported on 2023-02-15
Acknowledged KAUST grant number(s): BAS/1/1096-01-01
Acknowledgements: This study was funded by KAUST (BAS/1/1096-01-01). SSC was awarded scholarships from the Foundation for Research Support of the State of Rio de Janeiro (FAPERJ) and Coordination for the Improvement of Higher Education Personnel (CAPES).
We thank the Graduate Program of Plant Biotechnology and Bioprocesses (PBV) at the Federal University of Rio de Janeiro for supporting this work and Prof. Patricia Moura, Ricardo Chaloub and Alex Prast for their valuable suggestions to improve the manuscript. The graphical abstract was created by Heno Hwang, scientific illustrator at King Abdullah University of Science and Technology (KAUST).
ASJC Scopus subject areas