IESc Seminar Series: “Biodegradation of quaternary ammonium disinfectants: Mechanism, regulation and dissemination” By Assoc. Prof. Ulaş Tezel

Institute of Environmental Sciences Seminar Series

“Biodegradation of quaternary ammonium disinfectants: Mechanism, regulation and dissemination”

By Assoc. Prof. Ulaş Tezel

Institute of Environmental Sciences, Boğaziçi University

We cordially invite you to our seminar “Biodegradation of quaternary ammonium disinfectants: Mechanism, regulation and dissemination”, to be held by Assoc. Prof. Ulaş Tezel, Boğaziçi University, Institute of Environmental Sciences.

When: 21 April 2025, Monday, 14:30-15:30

Where: Institute of Environmental Sciences Seminar Room (Hisar Campus E-Block)

Contact: pinar.ertor@bogazici.edu.tr for any questions.

Abstract:

The SARS-CoV-2 outbreak in the last months of 2019 has changed our hygiene habits in line with our daily lives. We have been using more disinfectants, ignoring the fact that some bacteria can degrade those chemicals as well as they develop antibiotic resistance upon getting exposed to them. In this presentation we systematically demonstrate that a gene called QxyA is responsible for initialization of biodegradation of quaternary ammonium compounds (QACs), the active ingredient of most of the disinfectants used in SARS-CoV-2 control. QxyA codes a Rieske oxygenase that transforms QACs into a tertiary amine and an alkanoic acid. A tetR family suppressor is potentially regulating the expression of QxyA. We showed that QxyAR operon are present in a diverse group of bacteria isolated from wastewater, river, sea, soil, hospital and human blood. In those bacteria QxyAR operon is present in either IS1380 or Tn3 composite transposons. Given that many catabolic transposons have been detected on the IncP-1 group of plasmids with broad host range and high transfer rate, those transposable elements discovered may promote the transposition of the QxyAR operon to plasmids which result in its dissemination among bacteria especially during the period of pandemic. Therefore, aftermath of SARS-CoV-2 outbreak should be investigated more in depth to understand the potential health problems that we face in the future.

Short bio:

Ulas Tezel is an associate professor in the Institute of Environmental Sciences and the current Director of the Archaeometry Research Center at Boğaziçi University. He received his B.S. and M.S. degrees in Environmental Engineering from the Middle East Technical University, and the Ph.D. degree from the School of Civil and Environmental Engineering at Georgia Institute of Technology where he worked as a postdoctoral research scientist for 1.5 years before joining Boğaziçi University in 2012. His research is mainly on the occurrence and fate of emerging organic pollutants in the environment; pollutant biotransformation pathways and mechanisms; evolution and dissemination of antimicrobial resistance; microbial ecology and genetics