Carbon dioxide regulation of formate hydrogenlyase in Escherichia coli

1969 ◽  
Vol 36 (4) ◽  
pp. 567-575 ◽  
Author(s):  
H. Damon Swanson ◽  
James E. Ogg
Author(s):  
Magali Roger ◽  
Thomas C. P. Reed ◽  
Frank Sargent

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).


2017 ◽  
Vol 16 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Ana Claudia Berenhauser ◽  
Douglas Soares ◽  
Norton Komora ◽  
Juliano De Dea Lindner ◽  
Elane Schwinden Prudêncio ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 812 ◽  
Author(s):  
Monika Szymańska-Chargot ◽  
Monika Chylińska ◽  
Piotr M. Pieczywek ◽  
Anna Walkiewicz ◽  
Giorgia Pertile ◽  
...  

In this research, it was proposed to use carrot cellulose nanofibrils (CCNF) isolated from carrot pomace modified with silver nanoparticles (AgNPs) as a filler of polylactic acid (PLA) composites matrix. The new procedure was based on two steps: first, the preparation of nanocellulose modified with metal nanoparticles, and then the combination with PLA. Two concentrations—0.25 mM and 2 mM—of AgNO3 were used to modify CCNF. Then, PLA was mixed with the filler (CCNF/AgNPs) in two proportions 99:1 and 96:4. The influence of CCNF/AgNPs on mechanical, hydrophilic, thermal, and antibacterial properties of obtained nanocomposites was evaluated. The greatest improvement of mechanical properties was observed for composite containing CCNF with 2 mM of AgNPs, which obtained the lowest Young modulus and highest strain at break. The degradation temperature was lower for PLA with CCNF/AgNPs, but crystallization temperature wasn’t influenced. The addition of CCNF/AgNPs also increased hydrophilicity. The transmission rates of oxygen, nitrogen, and carbon dioxide also increased after the addition of CCNF/AgNPs to PLA. The antibacterial function against Escherichia coli and Bacillus cereus was obtained after the addition of AgNPs but only at the contact surface with the material made, suggesting the lack of migration of nanoparticles from the composite.


Microbiology ◽  
1997 ◽  
Vol 143 (11) ◽  
pp. 3633-3647 ◽  
Author(s):  
S. C. Andrews ◽  
B. C. Berks ◽  
J. McClay ◽  
A. Ambler ◽  
M. A. Quail ◽  
...  

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