Effect of Growth Stage on Bacterial Resistance to Chlorine Disinfection
The mechanisms involved in microbial resistance to chlorine disinfection have not been fully elucidated. In this study, we investigate the impact of cell growth stage on the chlorine disinfection efficiency during water treatment. Specifically, we determine the role of growth stage on chlorination resistance and compare the bacterial inactivation behaviors at different growth stages for E coli strains K12 and O157:H7. The inactivation rate constants, based on Chick-Watson kinetic equations, were estimated and compared for stationary phase and those at lag and exponential phase. Our results show that growing both E. coli strains cells obtained from different growth stages exhibited lower inactivation efficiency at stationary phase compared to those from lag and exponential phase. This implies that microbes in wastewater treatment process with varying solids retention time may show different chlorine resistance. The coefficient n of dilution was the lowest at exponential phase, indicating that cell inactivation becomes more sensitive to disinfectant at stationary phase. Higher inactivation rates were observed for the pathogenic O157:H7 than for K12 at different stages of growth. The strain-to-strain variability in survivability to chlorine exposure at different growth stages needs to be considered when selecting indicator microorganisms for water quality monitoring.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: 01 January 2010
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites