ARC Centre of Excellence in Synthetic Biology

Synthetic Biology


29, Jan 2024

Enzymes for biocatalysis and bioremediation

Researchers from the ARC Centre of Excellence in Synthetic Biology have discovered a new enzyme in a common soil bacterium which has significance for both biotechnology and environmental science.

Macquarie University Research Fellow Dr Nick Coleman and team studied a new monooxygenase enzyme in the bacterium Solimonas soli. Found in many kinds of bacteria, these enzymes perform important ecological roles, such as breaking down methane and ammonia which helps the environment. Think of them like natural cleaners that work to keep the environment in balance.

Dr Coleman says the study revealed previously unknown capabilities of Solimonas soli for bioremediation, including the breakdown of octane, a major component of petroleum, and phenol, a widely-used disinfectant. Furthermore, the newly-identified monooxygenase enzyme can biodegrade chlorinated pollutants such as vinyl chloride and cis-dichloroethene, common groundwater contaminants, found locally at sites such as the Botany Industrial Park in Sydney.

‘This organism – or a synthetic version containing the monooxygenase enzyme – may be useful for the clean-up of sites impacted by chlorinated alkene pollutants,’ Dr Coleman says.

The Soliomonas monooxygenase enzyme was shown to be capable of making epoxides from alkenes. Epoxides are building blocks for many everyday things such as plastics and medicines. Deeper understanding of this enzyme could lead to new industrial applications.

Some questions remain. The researchers found that while the enzyme oxidised many alkenes, it seems the bacterium itself doesn’t use these substances to grow. The researchers are still to determine what the enzyme’s main job is in natural environments because it seems that the alkenes aren’t its main food source.

The next step for this research is to delete the monooxygenase genes in Solimonas, and test the impact on the biology of the bacterium; this will help to address the above question of what this bug is eating in the wild. Future work will also involve improving the efficiency of the enzyme for industrial applications.

The findings are published with Environmental Microbiology.

Photo: Botany Bay Sunrise 1 by Brent Pearson (CC BY-ND 2.0 DEED)