Microbes play a crucial role in the environment, some of which can make people sick or spoil food, while others are essential for survival. These tiny organisms can also be engineered to produce specific molecules, leading researchers to investigate their potential in addressing greenhouse gas emissions. One such microbe, Cupriavidus necator H16, has been rewired to take in carbon dioxide (CO2) gas and produce mevalonate, a valuable building block for pharmaceuticals. The increasing concentration of greenhouse gases in the atmosphere has led to global warming, prompting the need for innovative solutions like microbial factories to tackle the issue.
Genetic engineering can modify the natural biosynthetic pathways of microbes, turning them into miniature living factories capable of producing various products. C. necator H16, a bacterium known for its ability to survive on CO2 and hydrogen gas, is a promising candidate for capturing and converting gases into larger molecules. However, the microbe’s plasmids, which contain genetic instructions, are relatively unstable and struggle to retain new information over time. Researchers aimed to improve C. necator’s ability to remember new instructions and produce useful carbon-based building blocks from CO2 gas.
The team focused on hacking C. necator’s biochemical pathways responsible for converting CO2 into larger six-carbon molecules. By pairing the new plasmid with an enzyme called RubisCo, crucial for utilizing CO2, cells that failed to remember the new instructions would also fail to produce RubisCo and ultimately die. This selective pressure ensured that cells with better memories would survive and replicate, passing along the plasmid to future generations. In tests, the engineered microbes were able to produce significantly more mevalonate, a key molecular building block with various pharmaceutical applications, compared to a control strain.
The research yielded the largest amounts of mevalonate from CO2 or other single-carbon reactants using microbes to date. The economic feasibility of this carbon fixation system makes it a promising option for reducing greenhouse gas emissions and producing valuable compounds from CO2. The results highlight the potential of microbial engineering in creating sustainable solutions for environmental challenges and pharmaceutical production. The researchers emphasize that this approach could be expanded to other microbial strains, offering a versatile and efficient strategy for carbon sequestration and molecule synthesis.
The study was funded by the Biotechnology and Biological Sciences Research Council and the Engineering and Physical Sciences Research Council of the United Kingdom, underscoring the importance of public investment in scientific research for advancing innovative technologies with environmental and economic benefits. By harnessing the power of microbial factories, researchers have demonstrated a novel approach to addressing greenhouse gas emissions and unlocking the potential of microbes in sustainable chemistry and engineering. The findings pave the way for future advancements in biotechnology and environmental science, showcasing the transformative impact of microbial manipulation in solving complex global challenges.