Using bacteria to produce fluorinated products sustainably
A new EU-project will focus on engineering bacteria to produce fluorinated compounds. Currently, these compounds can only be produced with traditional chemistry, which is costly and harmful to the environment.
By Anders Østerby Mønsted, Anne Wärme Lykke
Fluorinated compounds play an important role in our society. They are used in applications that range from pharma drugs (25% of all marketed drugs contain fluorine) to pesticides, polymers and complex materials such as non-stick coatings (Teflon®) and refrigerants. Today, fluorinated compounds are produced in traditional chemistry with the use of harsh chemicals that cause negative effects on the environment.
The ones being produced in nature are synthesized by some plants and bacteria in very small quantities.
A new EU-funded project, SinFonia, will come up with a more sustainable alternative to the current production of fluorinated products by engineering the robust bacterium Pseudomonas putida as a cell factory to make fluorinated polymers.
“We are working with a specific enzyme that can create a fluorine-to-carbon bond (one of the strongest bonds in organic chemistry) which is the first step in the production of fluorinated chemicals in a bio-based manner,” says Pablo Ivan Nikel, Senior Researcher and Group Leader at the Novo Nordisk Foundation Center for Biosustainability (DTU). He is leading the SinFonia project, which has received in total 8 million Euro on a four-year basis to develop this strategy further.
One of the main problems for the chemical industry is that fluorine is very difficult to handle due to its high reactivity and toxicity. The precise addition of fluorine to organic molecules is challenging and toxic by-products are flushed to the environment.
The project aims at producing fluorinated compounds in bacteria with metabolic engineering, circumventing the chemical reactions. Using the approach proposed in SinFonia opens the possibility of controlled fluorination of carbon structures within living cell factories.
The global market for fluorine is a billion-dollar industry. Therefore, producing high-value compounds in a cell factory would potentially be a major breakthrough towards a sustainable bioeconomy.
“Completely replacing existing production platforms is very challenging because the bio-based alternative is currently more expensive. But when it comes to high added-value, complex molecules, bio-based production will be both cleaner and cheaper, which makes it very interesting for the industry to invest money in”, says Pablo Ivan Nikel.
New-to-nature products as the new alternative
A big challenge going forward will be to design and construct efficient fluorination pathways in order to make a cell factory that is able to biologically produce fluoropolymers, with uses as self-cleaning surfaces and low-surface-energy coatings, for instance in electronic components.
This will nevertheless not be an easy task since fluorine is not a natural part of the biochemistry of the cells. Thus, it will be necessary to couple the activity of the synthetic fluorination pathway with essential metabolic functions in the cell to make it ‘addict’ to fluorine.
“Our goal is to make the cells dependent on the fluorination pathways to grow and survive. If the cell factory can then produce these polymers it will at least partially replace parts of the traditional chemistry that is used for fluorination with new-to-nature products”, says Pablo Ivan Nikel.
So far, fluoropolymers are not produced by engineered bacteria and they can only be obtained by complex chemical reactions.
If this is about to change in the future, several companies have already expressed interest in the new technology. Most of the focus should be turned towards targeting high added-value compounds, according to the project coordinator.
source: Technical University of Denmark