Evolved Bacterial Enzyme Boosts Pollutant Degradation
The TmrA enzyme now degrades 1,1-dichloroethane four times faster after undergoing targeted laboratory evolution.
Updated on Oct. 31, 2026 in Life Sciences
Researchers successfully evolved the bacterium Dehalobacter restrictus strain UNSWDHB to improve its ability to degrade 1,1-dichloroethane. This research-stage achievement demonstrates that laboratory evolution can tune specific enzymes to process non-native substrates.
Why it matters
Optimizing microbial pathways through adaptive evolution provides a scalable method for environmental remediation of chemical contaminants. By forcing bacteria to evolve against specific substrate ratios, researchers can accelerate the development of organisms capable of breaking down persistent industrial pollutants.
The TmrA enzyme showed an increased binding affinity for 1,1-dichloroethane by nearly two orders of magnitude. Polar solvation energy penalties during this engagement decreased by 3.2 kcal/mol, while baseline chloroform binding free energy held steady at -8.5 kcal/mol.
The players
Dehalobacter restrictus
A genus of anaerobic, organohalide-respiring bacteria used in environmental bioremediation research to degrade chlorinated pollutants.
The details
The team applied selective pressure using a 1:9 chloroform to 1,1-dichloroethane substrate ratio during continuous culture growth. This pressure forced the TmrA enzyme—a protein that catalyzes the removal of halogen atoms from organic compounds—to undergo mutations at positions Val84Ile, Glu255Asp, and Ala267Val. These substitutions localized within the enzyme's flexible, high-entropy domains, effectively lowering the energy barrier required to bind the non-native 1,1-dichloroethane molecule.
Timeline
October 31, 2026: The research results were published.
The Tech Race
This effort builds on the established practice of using Dehalobacter restrictus to neutralize trichloroethene in contaminated sites. By applying adaptive evolution, researchers are attempting to expand the metabolic toolkit of these microbes to handle a wider array of chlorinated industrial chemicals.
This development is currently limited to laboratory research and is not yet available for field-based environmental remediation. Future implementation will depend on further testing to ensure these evolved strains can outcompete indigenous microbial populations in real-world soil conditions.
The takeaway
Laboratory-evolved strains demonstrate a clear path toward enhancing the degradation efficiency of persistent industrial pollutants. Future research to watch will involve field trials to confirm if these evolved enzymatic binding affinities remain stable in non-controlled environmental conditions.
Further reading
For more on how microbial engineering is advancing environmental cleanup, visit our Life Sciences section.
Source note: This article includes information reported by Alwasat-ye.
