scholarly journals Efficient hydrogen-dependent carbon dioxide reduction byEscherichia coli

2017 ◽  
Author(s):  
Magali Roger ◽  
Fraser Brown ◽  
William Gabrielli ◽  
Frank Sargent
Keyword(s):  
Carbon Dioxide ◽  
Carbon Capture ◽  
Physiological Role ◽  
Experimental System ◽  
Carbon Dioxide Reduction ◽  
Reverse Reaction ◽  
Pressure System ◽  
E Coli ◽  
Major Route ◽  
Carbon Dioxide Cycling

ABSTRACTThe formate hydrogenlyase (FHL) complex ofEscherichia coliis normally produced under anaerobic fermentative conditions when its physiological role is to oxidise formate to carbon dioxide and couple that reaction directly to the reduction of protons to molecular hydrogen. This forward reaction is the major route of hydrogen production byE. coliand the physiology, genetics and biochemistry of this process are reasonably well understood. However, studies of the reverse reaction - hydrogen-dependent carbon dioxide reduction – have been rather less extensive. Harnessing the alternative reverse reaction has the potential to unlock FHL as a carbon dioxide cycling enzyme, or could potentially lead to the development of bio-based carbon capture technologies. In this work, it is established that FHL can operate as a highly efficient CO2reductase. A controllable pressure system was designed with the intention of maximising substrate availability to the FHL enzyme. By placing gaseous CO2and H2are under pressure (up to 10 bar), and by using a compartmentalised intact whole cell approach where the produced formate is excreted, the optimised experimental system was observed to convert 100 % of gaseous CO2to formic acid and generate >500 mM formate in solution at an initial rate of 1.2 g formateperlitreperhour.

scholarly journals Harnessing Escherichia coli for bio-based production of formate under pressurized H 2 and CO 2 gases.

2021 ◽  
Author(s):  
Magali Roger ◽  
Thomas C. P. Reed ◽  
Frank Sargent
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
Formic Acid ◽  
Carbon Capture ◽  
Continuous Production ◽  
Carbon Capture And Storage ◽  
Physiological Role ◽  
Anaerobic Growth ◽  
Formate Hydrogenlyase ◽  
And Storage

Escherichia coli is gram-negative bacterium that is a workhorse for biotechnology. The organism naturally performs a mixed-acid fermentation under anaerobic conditions where it synthesises formate hydrogenlyase (FHL-1). The physiological role of the enzyme is the disproportionation of formate in to H 2 and CO 2 . However, the enzyme has been observed to catalyse hydrogenation of CO 2 given the correct conditions, and so has possibilities in bio-based carbon capture and storage if it can be harnessed as a hydrogen-dependent CO 2 -reductase (HDCR). In this study, an E. coli host strain was engineered for the continuous production of formic acid from H 2 and CO 2 during bacterial growth in a pressurised batch bioreactor. Incorporation of tungsten, in place of molybdenum, in FHL-1 helped to impose a degree of catalytic bias on the enzyme. This work demonstrates that it is possible to couple cell growth to simultaneous, unidirectional formate production from carbon dioxide and develops a process for growth under pressurised gases. IMPORTANCE Greenhouse gas emissions, including waste carbon dioxide, are contributing to global climate change. A basket of solutions is needed to steadily reduce emissions, and one approach is bio-based carbon capture and storage. Here we present out latest work on harnessing a novel biological solution for carbon capture. The Escherichia coli formate hydrogenlyase (FHL-1) was engineered to be constitutively expressed. Anaerobic growth under pressurised H 2 and CO 2 gases was established and aqueous formic acid was produced as a result. Incorporation of tungsten in to the enzyme in place of molybdenum proved useful in poising FHL-1 as a hydrogen-dependent CO 2 reductase (HDCR).

scholarly journals Harnessing Escherichia coli for bio-based production of formate under pressurized H2 and CO2 gases

2021 ◽  
Author(s):  
Magali Roger ◽  
Tom C. Reed ◽  
Frank Sargent
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Host Strain ◽  
Acid Fermentation ◽  
E Coli ◽  
Mixed Acid ◽  
Batch Bioreactor ◽  
Growth Deficiency

ABSRACTEscherichia coli is gram-negative bacterium that is a workhorse of the biotechnology industry. The organism has a flexible metabolism and can perform a mixed-acid fermentation under anaerobic conditions. Under these conditions E. coli synthesises a formate hydrogenlyase isoenzyme (FHL-1) that can generate molecular hydrogen and carbon dioxide from formic acid. The reverse reaction is hydrogen-dependent carbon dioxide reduction (HDCR), which has exciting possibilities in bio-based carbon capture and storage if it can be harnessed. In this study, an E. coli host strain was optimised for the production of formate from H2 and CO2 during bacterial growth in a pressurised batch bioreactor. A host strain was engineered that constitutively produced the FHL-1 enzyme and incorporation of tungsten in to the enzyme, in place of molybdenum, helped poise the reaction in the HDCR direction. The engineered E. coli strain showed an ability to grow under fermentative conditions while simultaneously producing formate from gaseous H2 and CO2 supplied in the bioreactor. However, while a sustained pressure of 10 bar N2 had no adverse effect on cell growth, when the culture was placed at or above 4 bar pressure of a H2:CO2 mixture then a clear growth deficiency was observed. Taken together, this work demonstrates that growing cells can be harnessed to hydrogenate carbon dioxide and provides fresh evidence that the FHL-1 enzyme may be intimately linked with bacterial energy metabolism.

CO2 Reduction to Propanol by Copper Foams: A Pre- and Post-Catalysis Study

2020 ◽  
Author(s):  
Jennifer A. Rudd ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin Bain ◽  
Sunyhik Ahn ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Photoelectron Spectroscopy ◽  
Carbon Capture ◽  
Surface Composition ◽  
Co2 Reduction ◽  
Structural Rearrangement ◽  
Copper Electrode ◽  
Ex Situ ◽  
X Ray ◽  
Copper Electrodes

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For <i>n</i>-propanol production, faradaic efficiencies reach 4.93% at -0.83 V <i>vs</i> RHE, with a geometric partial current density of -1.85 mA/cm<sup>2</sup>. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized <i>ex-situ</i> using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.

Fundamentals, On-Going Advances and Challenges of Electrochemical Carbon Dioxide Reduction

2021 ◽  
Author(s):  
Zongkui Kou ◽  
Xin Li ◽  
Tingting Wang ◽  
Yuanyuan Ma ◽  
Wenjie Zang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Reduction

scholarly journals Investigation into the Re-Arrangement of Copper Foams Pre- and Post-CO2 Electrocatalysis

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 687-703
Author(s):  
Jennifer A. Rudd ◽  
Sandra Hernandez-Aldave ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin J. E. Bain ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbon Dioxide ◽  
Carbon Capture ◽  
Surface Composition ◽  
Structural Rearrangement ◽  
Copper Electrode ◽  
Copper Electrodes ◽  
Porous Copper ◽  
Chemical Products ◽  
Co2 Electrolysis

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher-value chemical products. Herein, we fabricated a porous copper electrode capable of catalyzing the reduction of carbon dioxide into higher-value products, such as ethylene, ethanol and propanol. We investigated the formation of the foams under different conditions, not only analyzing their morphological and crystal structure, but also documenting their performance as a catalyst. In particular, we studied the response of the foams to CO2 electrolysis, including the effect of urea as a potential additive to enhance CO2 catalysis. Before electrolysis, the pristine and urea-modified foam copper electrodes consisted of a mixture of cuboctahedra and dendrites. After 35 min of electrolysis, the cuboctahedra and dendrites underwent structural rearrangement affecting catalysis performance. We found that alterations in the morphology, crystallinity and surface composition of the catalyst were conducive to the deactivation of the copper foams.

Sign in / Sign up

Export Citation Format

Share Document