Schwering, Monika C.2012-07-062012-07-062012-07-06http://hdl.handle.net/1880/49094Waterborne disease outbreaks are especially dangerous in immunocompromised individuals and can be caused by biofilm formation in water systems. The aim of this work was to collect a group of environmental isolates, including opportunistic pathogens, from treated water systems with the purpose of creating a model drinking water system biofilm. This model biofilm would be used to explore the resistance of biofilms to chlorine at levels typical of a water distribution system. Isolates for the model biofilm were collected from Calgary and Ontario, sequenced and then as single and multi-species biofilms exposed to chlorine. The resistance, biofilm structure and microbial community were examined. It was found that biofilm organisms are consistently more resistant than planktonic and that multi-species biofilms even more so. Little change was seen in biofilm communities after treatment. The 3D structure of the biofilm appeared to have a role in resistance by limiting diffusion and protecting inner cells.engAttribution Share-Alike 3.0 UnportedUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.http://creativecommons.org/licenses/by-sa/3.0/Drinking WaterDisinfectionChlorineBiofilmsmaster thesis1209010.11575/PRISM/21613