In future, greenhouse gas carbon dioxide could be removed from the atmosphere by deploying a new biological method. A team headed by Tobias Erb, Leader of a Research Group at the Max Planck Institute for Terrestrial Microbiology in Marburg, has developed a synthetic but completely biological metabolic pathway based on the model of photosynthesis that fixes carbon dioxide from the atmosphere 20% more efficiently that plants can photosynthetically. The researchers initially planned the new system, which they presented in the magazine Science this week, on the drawing board and then turned it into reality in the laboratory.
Climate change is one of the most pressing challenges of our time. The concentration of carbon dioxide (CO2) in the atmosphere owing to human activities has continually risen since the start of the Industrial Revolution. All scientific evidence indicates that this increase is exacerbating the greenhouse effect and changing the climate. The consequences are already clearly evident. To overcome the environmental as well as the social challenge of climate change, “we must find new ways of sustainably removing excessive CO2 from the atmosphere and turning it into something useful,” underlined Erb, who leads a Junior Research Group at the Max Planck Institute in Marburg.
Theoretically, the problem could be tackled through greater productivity in agriculture and forestry. This is because plants fix carbon dioxide from the atmosphere through photosynthesis. They produce sugar for food from the CO2 via a gradual process known as the Calvin cycle. Each individual biochemical step towards producing the sugar is initiated or accelerated by its own enzyme. The various biocatalysts are precisely aligned with one another to ensure they can work together. However, there is a problem. The CO2-fixing enzyme in the Calvin cycle in plants, which is known by experts as RuBisCo, is relatively slow. It also frequently makes mistakes. RuBisCo captures an oxygen molecule instead of CO2 in one in five reactions.