Scientists recruit cyanobacteria to create ‘clean’ chemicals

Researchers at the Ruhr Universität Bochum (RUB) said they had already genetically modified cyanobacteria, to create cells that could produce enzymes for the manufacture of basic and fine chemicals.

Their experiments demonstrate that enzymes from other organisms can be successfully introduced into cyanobacteria and used in a number of reactions, RUB researchers said.

The outstanding selectivity is crucial for deployment in industrial applications

Robert Kourist, RUB

The bacteria can also supply the energy required by the enzymes by performing photosynthesis, which must otherwise be supplied in the form of sugar or other high-energy bonds.

This means no external supply of chemical energy is necessary.

“During photosynthesis, light energy is initially converted into chemical energy, said Marc Nowaczyk, chair of Plant Biochemistry at RUB.

"In the second step, that energy is mainly used for binding of carbon dioxide. However, a small percentage of the energy remains and can be directly utilised.”

The new approach is to decouple the supplied chemical energy from carbon fixation and use it directly for chemical reactions.

The researchers said they had also observed that cyanobacteria catalyse only the synthesis of the desired chemical product in their experiments, which allows them to function selectively. This compares with many current catalytic processes, which will often produce a mirrored product that must then be filtered out.

“The outstanding selectivity is crucial for deployment in industrial applications,” said Robert Kourist, from the RUB’s junior research group, Mikrobielle Biotechnologie.

“The chemical industry has to become cleaner.”

A report on the work has been published in the Angewandte Chemie journal.