Over the course of several months, researchers in Israel created strains of E coli bacteria. These use CO2 to generate energy instead of organic compounds. Such an achievement in synthetic biology highlights the incredible plasticity of bacterial metabolism. The study could also form the framework for future climate-neutral bioproduction.
E coli bacteria as energy sources
The living world is divided into autotrophs and heterotrophs. The former convert inorganic CO2 into biomass, while the latterorganic compoundsconsume. Autotrophic organisms dominate the biomass on Earth and provide much of our food and fuel. A better understanding of the principles of autotrophic growth and methods to improve it is crucial to the path to sustainability.
“Our main goal was to create a practical scientific platform to improve CO2 consumption. This can help address the challenges associated with sustainable food and fuel production, as well as global warming caused by CO2 emissions.” That's what lead author Ron Milo, a systems biologist at the Weizmann Institute of Science, says. “The transformation of carbonof coli bacteria, the workhorse of biotechnology, from organic carbon to CO2 is an important step towards building such a platform.”
A major challenge in synthetic biology was therefore to generate synthetic autotropy in a heterotrophic model organism. Despite widespread interest in renewable energy storage and more sustainable food production, past efforts to develop industrially relevant heterotrophic model organisms to use CO2 as the sole carbon source have failed. Previous attempts to establish autocatalytic cyclic CO2 fixation in heterotrophs always required the addition of organic compounds with multiple carbon atoms to achieve stable growth.
New perspectives for sustainability
“From a fundamental science perspective, we wanted to find out whether such a fundamental change in the diet of bacteria, from relying on sugar to synthesizing all of their biomass from CO2, is possible.” This is what author Shmuel Gleizer, a postdoctoral researcher at the Weizmann Institute of Science, says. “We didn’t just want to test the feasibility of such a transformation in the laboratory. “We should also know how extreme an adaptation is in terms of changes to the bacterial DNA blueprint.”
In future work, researchers will attempt to provide energy through renewable electricity to address the problem of CO2 release. This also allows them to determine whether atmospheric conditions can support autotrophy. Accordingly, these mutations that are most relevant to autotrophic growth can then be narrowed down.
You can find out more about this inthis article.
