Cell
Volume 179, Issue 6, 27 November 2019, Pages 1255-1263.e12
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Article
Conversion of Escherichia coli to Generate All Biomass Carbon from CO2

Under a Creative Commons license
open access

Highlights

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Conversion of obligate heterotroph to full autotrophy over laboratory timescales

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Non-native Calvin cycle operation generates biomass carbon from CO2 in E.?coli

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Formate is oxidized by heterologous formate dehydrogenase to provide reducing power

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Chemostat-based directed evolution led to complete trophic mode change in ¡Ö200?days

Summary

The living world is largely divided into autotrophs that convert CO2 into biomass and heterotrophs that consume organic compounds. In spite of widespread interest in renewable energy storage and more sustainable food production, the engineering of industrially relevant heterotrophic model organisms to use CO2 as their sole carbon source has so far remained an outstanding challenge. Here, we report the achievement of this transformation on laboratory timescales. We constructed and evolved Escherichia coli to produce all its biomass carbon from CO2. Reducing power and energy, but not carbon,?are supplied via the one-carbon molecule formate, which can be produced electrochemically. Rubisco and phosphoribulokinase were co-expressed with formate dehydrogenase to enable CO2 fixation and reduction via the Calvin-Benson-Bassham cycle. Autotrophic growth was achieved following several months of continuous laboratory?evolution in a chemostat under intensifying organic?carbon limitation and confirmed via isotopic labeling.

Keywords

synthetic autotrophy
carbon fixation
Rubisco
adaptive laboratory evolution
synthetic biology
sustainability
metabolic rewiring
Escherichia coli
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Present address: Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, New York, NY 10065, USA

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Present address: Institute of Molecular Systems Biology, ETH Z¨¹rich, Z¨¹rich, Switzerland

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Present address: Max Planck Institute of Molecular Plant Physiology, Am M¨¹hlenberg 1, Potsdam 14476, Germany

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Lead Contact