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Photorespiration is the second largest carbon flux in most leaves and is integrated into metabolism broadly including one-carbon (C1) metabolism. Photorespiratory intermediates such as serine and others may serve as sources of C1 units, but it is unclear to what degree this happens in vivo, whether altered photorespiration changes flux to C1 metabolism, and if so through which intermediates. To clarify these questions, we quantified carbon flux from photorespiration to C1 metabolism using 13CO2 labelling and isotopically non-stationary metabolic flux analysis in Arabidopsis thaliana under different O2 concentrations which modulate photorespiration. The results revealed that ~5.8% of assimilated carbon passes to C1 metabolism under ambient photorespiratory conditions, but this flux greatly decreases under limited photorespiration. Furthermore, the primary carbon flux from photorespiration to C1 metabolism is through serine. Our results provide fundamental insight into how photorespiration is integrated into C1 metabolism, with possible implications for C1 metabolic response to climate change.
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This content will become publicly available on June 1, 2026
Pathways to sustainability: a quantitative comparison of aerobic and anaerobic C1 bioconversion routes
One-carbon (C1) substrates are attractive feedstocks for biological upgrading as part of a circular, carbon-negative bioeconomy. Nature has evolved a diverse set of C1-trophs that use a variety of pathways. Additionally, intensive effort has recently been invested in developing synthetic C1 assimilation pathways. This complicated landscape presents the question: “What pathways should be used to produce what products from what C1 substrates?” To guide the selection, we calculate and compare maximal theoretical yields for a range of bioproducts from different C1 feedstocks and pathways. The results highlight emerging opportunities to apply metabolic engineering to specific C1 pathways to improve pathway performance. Since the C1 landscape is dynamic, with new discoveries in the biochemistry of native pathways and new synthetic alternatives rapidly emerging, we present detailed procedures for these yield calculations to enable others to easily adapt them to additional scenarios as a foundation for establishing industrially relevant production strains.
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- Award ID(s):
- 2345872
- PAR ID:
- 10608898
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Current Opinion in Biotechnology
- Volume:
- 93
- Issue:
- C
- ISSN:
- 0958-1669
- Page Range / eLocation ID:
- 103310
- Subject(s) / Keyword(s):
- C1 Metabolism Microaerobic Co-Culture Theoretical Yield Methanol
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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