Engineered microbes efficiently convert CO2 into key pharmaceutical precursors

Engineered microbes efficiently convert CO2 into key pharmaceutical precursors
by Clarence Oxford
Los Angeles CA (SPX) Sep 01, 2024

While many microbes are known for causing illness or spoiling food, others are crucial for sustaining life and can be engineered to produce specific compounds. Researchers from 'ACS Sustainable Chemistry and Engineering' have successfully modified a microbe to capture carbon dioxide (CO2) from the atmosphere and convert it into mevalonate, a valuable building block for pharmaceutical applications.

The global increase in greenhouse gases, particularly CO2, has significantly contributed to climate change. To combat this, it is necessary not only to reduce ongoing emissions but also to actively remove existing CO2 from the atmosphere. One promising strategy involves the use of microbes, which can be genetically engineered to produce a variety of useful compounds, much like they are currently used to manufacture insulin.

The bacterium 'Cupriavidus necator' H16, a microorganism that can survive on CO2 and hydrogen gas, has shown great potential for this purpose. However, the microbe's ability to retain engineered genetic instructions over time has been a challenge due to the instability of the plasmids (genetic instructions). Katalin Kovacs and her team addressed this issue by enhancing the stability of these plasmids, ensuring the bacterium could reliably produce valuable carbon-based compounds from CO2.

The researchers focused on improving the microbe's biochemical pathways that convert CO2 into larger molecules, specifically a six-carbon compound known as mevalonate. They achieved this by pairing the plasmid with an enzyme called RubisCo, which is essential for the bacterium's ability to utilize CO2. If a cell forgets the new genetic instructions, it would also lose the ability to produce RubisCo, leading to its death. This approach ensures that only the most efficient and stable cells survive and replicate.

In laboratory tests, the engineered microbes produced significantly higher amounts of mevalonate compared to control strains. Mevalonate is a critical precursor for various substances, including cholesterol and steroid molecules, which have wide-ranging applications in both natural and synthetic systems. The study's results represent the highest yield of mevalonate produced from CO2 using microbial methods to date. The researchers believe this innovative approach could be more economically viable than previous methods and could be adapted for use with other microbial strains.

Research Report:Stable Platform for Mevalonate Bioproduction from CO2