Geneguard: A model system for chlorophenol degradation.
Biosafety is the major concern in bioengineering research. We developed a toxin-antitoxin (TA) system to address this concern. The TA system can self-regulate the growth of engineered bacteria. To validate the system, we applied it to the bio-treatment of phenolic pollution. Phenolic substances are widely used as one important raw material in industrial and agricultural production. However, water pollution resulted from the leakage or non-compliance of the emissions becomes a huge threaten to human health. Bio-treatment methods have been widely used over the years and have proven to be efficient. Nonetheless, difficulties in separation and cultivation of natural bacterial strains necessitate an improved method based on engineered bacteria. Therefore, we implemented the TA system with the protein DmpR, which works as the sensor to detect phenolic signals and expressed monooxygenase as well as antitoxin in E. Coli. In the absence of pollutants, the continuously expressed toxin can inhibit bacterial growth. When exposed to pollutants, the expression of antitoxin and monooxygenase regulated by DmpR will be activated to block the toxicity and dispose phenolic pollutants, respectively.