Israeli scientists designed a bacterium capable of eating CO2 and contributing to the fight against climate change
A group of Israeli scientists has designed a bacterium capable of feeding on carbon dioxide (CO2), in an effort to combat climate change.
The researchers created a strain of E. coli that consumes carbon dioxide instead of sugarIn a breakthrough that could smooth the shift to carbon-neutral fuels, researchers at the Weizmann Institute of Science created this genetically modified bacterium, capable of surviving by consuming carbon dioxide instead of sugar.
The researchers created a strain of E. coli that consumes CO2 for energy instead of organic compounds. They explained that autotrophic growth (which makes its own organic matter from inorganic substances) was achieved after several months of continuous evolution in the laboratory, in a chemostat (special production tank for bacteria) under intensifying organic carbon limitation and confirmed by isotopic tagging (a scientific method by which certain atoms are replaced by an isotope in a molecule).
Through genetic engineering they succeeded in having bacteria convert CO2 into organic carbon, replacing the energy of the sun, a vital ingredient in the photosynthesis process, with a substance called formate, which also attracts attention as a potential generator of clean electricity.
|Strain of E. coli that consumes carbon dioxide instead of sugar 2019.|
The team used "metabolic routing" to help transform E. coli's diet and make it consume CO2 in a plant-like manner. This method is an adaptation to conditions of low nutrient and oxygen content in the microenvironment, which allow the cells to hyperproliferative. This involved adding genes that metabolize CO2 and eliminating genes that generally process sugar compounds.
"From a basic scientific perspective, we wanted to see if such a major transformation in the diet of bacteria is possible, from sugar dependence to the synthesis of all their biomass from CO2," said the first author of the research, Shmuel Gleizer.
"Beyond testing the viability of such a transformation in the laboratory, we wanted to know how extreme an adaptation in terms of changes in the bacterial DNA model should be," he added.
Gleizer and other scientists at the Weizmann Institute highlighted the "incredible plasticity of bacterial metabolism.
From intestinal bacteria dependent on sugar to bacteria based on carbon dioxide.Our main goal was to create a convenient scientific platform that could improve CO2 fixation, which can help address the challenges related to sustainable food and fuel production and global warming caused by CO2 emissions, said lead author Ron Milo, systems biologist at the Institute.
The extraordinary discovery, reported Wednesday in Cell and picked up by the prestigious science journal Nature, could lead to the production of low carbon emissions for use in biofuels or food, which would help eradicate excess CO2 in the atmosphere.
Our laboratory was the first to pursue the idea of changing the diet of a normal heterotrophic to autotrophism, Milo said. It seemed impossible at first, but it has taught us many lessons along the way, and in the end we show that it can be done. Our findings are an important milestone toward our goal of efficient and green science applications, he added.
Laboratory bacteria that switched to a CO2 diet were fed very high amounts of gas. However, under regular atmospheric conditions, they would still need sugar to live.
The authors say an important limitation is that the bacteria currently release more CO2 than is consumed through carbon sequestration. In addition, further research is needed before it is possible to discuss the scalability of the approach for industrial use.
However, they said their next step will be to aim to supply energy through renewable electricity to address the problem of CO2 release and improve their understanding of the conditions under which bacteria can flourish.
"This accomplishment is a powerful proof-of-concept that opens up a new and exciting prospect of using modified bacteria to transform products we consider residues into fuel, food or other compounds of interest," concluded Professor Milo.
ARTICLE VOLUME 179, ISSUE 6, P1255-1263.E12, NOVEMBER 27, 2019, PDF [2 MB].
Conversion of Escherichia coli to Generate All Biomass Carbon from CO2
- Shmuel Gleizer, climate change 2019.
- Roee Ben-Nissan, climate change 2019.
- Yinon M. Bar-On, climate change 2019.
- Melina Shamshoum, climate change 2019.
- Arren Bar-Even, climate change 2019.
- Ron Milo, climate change 2019.