Reducing Water Pollution

Quaternary ammonium compounds (QACs)are the most commonly used hard surface disinfectants. Often found in hospitals, the most commonly used QACs are benzalkonium chlorides (BACs) which have many antimicrobial properties. These disinfectants, however, are released into the environment either directly or through wastewater treatment plants that are not designed to treat these types of pollutants. The presence of BACs in the water systems increases public health problems and even decreases antimicrobial resistance. BACs can be degraded into benzyldimethyl amines (BDMAs) which are five hundred times less toxic than BACs. There are several microorganisms in the environment that are capable of this degradation (Ertekin et al. 2017). Scientists performed an experiment to find an enzyme that could be applied to wastewater treatment technologies to reduce the number of BACs in our water by degrading them to less toxic BDMAs. One oxygenase was chosen and mentioned as oxyBAC. In the experiment, scientists used two samples of E. coli. One sample of the bacteria E. coli had oxyBAC added to it, and the other sample of E. coli remained untouched. The sample with the oxyBAC enzyme successfully degraded BACs to BDMAs while the sample without the oxyBAC enzyme did not. 

Demonstration of sample of E.coli with oxyBAC degrading BAC to BDMA and 

sample of E. coli with no treatment unable to degrade BACs to BDMA (Ertekin et al. 2017)

This means that oxyBAC could be added to wastewater treatment plants, and poorly treated wastewater from hospitals and industrial plants, to degrade BACs to less toxic BDMAs. It can also be applied to natural environments contaminated with BACs. However, since the oxyBAC enzyme decreases the antimicrobial properties of BACs, it is important that indoor environments, such as those in hospitals that require antimicrobial disinfectants, are not contaminated with the enzyme.

References: Ertekin, E., K.T. Konstantinidis, U. Tezel. 2017. A Rieske-Type Oxygenase of Pseudomonas sp. BIOMIG1 Converts Benzalkonium Chlorides to Benzyldimethyl Amine. Environ. Sci. Technol. 2017, 51, 1, 175 - 181.