Conversion of Escherichia coli to Generate All Biomass Carbon from CO2

Vita.Infrared spectroscopy was used to examine the surface properties of catalytic La₂Og₃ and a 1:1 mixture of LaOCl + La₂Og₃. Spectral studies of the dehydration/rehydration of the La(OH)₃/La₂O₃ system revealed the existence of two distinct kinds of bulk hydroxide ions in La(OH)₃, giving rise to infrared bands at 3610 and 3590 cm⁻¹. The former band is preferentially removed during the first stage of dehydration to LaOOH. The latter band, corresponding to the more strongly-bound type of OH⁻, is removed during the second-stage dehydration of the oxyhydroxide to La₂Og₃. No evidence was observed for either bulk or surface hydroxyls on La₂Og₃ above 300°C. CO₂ adsorption on La₂Og₃ results in the formation of unidentate and bidentate carbonate species. Formation of the latter species suggests the existence of anion vacancies on the oxide surface. CO²₃⁻ species formed on La₂Og₃ are completely removed by evacuation at (greater than or equal sign) 350°C. CO₂ adsorption on La(OH)₃ results in preferential hydrogen displacement from the type of surface hydroxide ion whose 0-H stretching band appears at 3590 cm⁻¹. Unidentate carbonate species similar to those observed on La₂Og₃ are formed on La(OH)₃.

Conversion of Escherichia coli to Generate All Biomass Carbon from CO2

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.ISSN:0092-8674ISSN:1097-417