What could go wrong? ~cr
Feat could turn bacteria into biological factories for energy and even food.
The bacterium Escherichia coli has been engineered to grow by consuming carbon dioxide.Credit: Steve Gschmeissner/SPL
E. coli is on a diet. Researchers have created a strain of the lab workhorse bacterium — full name Escherichia coli — that grows by consuming carbon dioxide instead of sugars or other organic molecules.
The achievement is a milestone, say scientists, because it drastically alters the inner workings of one of biology’s most popular model organisms. And in the future, CO2-eating E. coli could be used to make organic carbon molecules that could be used as biofuels or to produce food. Products made in this way would have lower emissions compared with conventional production methods, and could potentially remove the gas from the air. The work is published in Cell1 on 27 November.
“It’s like a metabolic heart transplantation,” says Tobias Erb, a biochemist and synthetic biologist at the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany, who wasn’t involved in the study.
Plants and photosynthetic cyanobacteria — aquatic microbes that produce oxygen — use the energy from light to transform, or fix, CO2 into the carbon-containing building blocks of life, including DNA, proteins and fats. But these organisms can be hard to genetically modify, which has slowed efforts to turn them into biological factories.
By contrast, E. coli is relatively easy to engineer, and its fast growth means that changes can be quickly tested and tweaked to optimize genetic alterations. But the bacterium prefers to grow on sugars such as glucose — and instead of consuming CO2, it emits the gas as waste.
Ron Milo, a systems biologist at the Weizmann Institute of Science in Rehovot, Israel, and his team have spent the past decade overhauling E. coli’s diet. In 2016, they created2 a strain that consumed CO2, but the compound accounted for only a fraction of the organism’s carbon intake — the rest was an organic compound that the bacteria were fed, called pyruvate.