Designing protective suits for hard-working bacteria – ScienceDaily


Chemical factories produce a variety of products every day that are difficult to do without in a modern society; everything from drugs like insulin and antibiotics to fertilizers.

Such products are often based on bacteria, which can efficiently manufacture chemicals and medicines without producing toxic by-products, which benefits the environment and sustainability.

A major challenge for these hard-working bacteria is that they may need to be exposed to a variety of stressors to produce the desired product: some bacteria need exposure to high heat, others to high pH, ​​and still others to organic solvents. Although industrial bacteria are tough, this often leads to their death and ultimately low efficiency.

More robust bacteria

Changzhu Wu, Head of Research at the Department of Chemistry, Physics and Pharmacy, University of Southern Denmark, and his research team are working to develop more sustainable chemical processes and are now introducing a new technique that makes bacterial cells more robust and efficient for various chemical synthesis under harsh conditions .

The team describes their new method, which is based on the model bacterium E. coli in the scientific journal nature communication.

Most people probably think of E. coli as a bacterium that can contaminate drinking water and cause disease, but most bacteria of this type occur naturally in our gut and are harmless.

Make E. coli stronger

E. coli is widely used in the manufacture of many important types of medicines and chemicals in industry because it grows quickly and is both easy and safe to process.

“But like other bacteria in industry, you lose a lot of them along the way. They just die from the harsh conditions they are presented with during the process, and that reduces efficiency,” explains Changzhu Wu.

It is therefore his idea that E. coli Bacteria in a kind of protective suit so that they become more resistant.

The new protective suit consists of nanoparticles of dopamine (known in chemical circles as protection against external stressors such as light) and the formula is simple: E. coli Bacteria, dopamine and liquid are mixed, immediately afterwards the dopamine attaches itself in the form of nanoparticles to the cell surface of the bacteria.

“With the protective suit, the bacterium is protected from UV radiation, heat and several organic solvents,” the researchers write in their scientific article.

Good for sustainability

A E. coli Bacteria without a protective suit rarely survive more than two hours when exposed to UV radiation. Wearing the protective suit, over 85% are still alive after two hours.

The researchers also tested the bacteria’s response to drastic phase shifts (e.g. in a gas phase changing to a liquid, from liquid to solid, etc.). 90% of the unprotected bacterial cells died, while 80% of the protected cells survived.

“With such high survival rates, you can expand the production of chemical substances E. coli Bacteria, which is good for the environment and sustainability,” Changzhu Wu concludes.

Industrial use of bacteria, examples:

  • Corynebacterium glutamicum for lysine production, dietary supplements in the feed, food and beverage industry.
  • Penicillium chrysogenum for penicillin production
  • Streptomyces griseus for streptomycin production (antibiotics)
  • Halomonas bluephagnese for PHB production (plastics)
  • Kloeckera apiculata for alcohol production.
  • E. coli for the production of insulin and growth hormones.

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Materials provided by University of Southern Denmark. Note: Content can be edited for style and length.


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