Document Type


Degree Name

Master of Science (MSc)




Faculty of Science

First Advisor

Dr. Geoff Horsman

Advisor Role


Second Advisor

Dr. Michael Suits

Advisor Role


Third Advisor

Dr. Joel Weadge

Advisor Role



Commonly associated with severe inflammation and destruction of the tooth-supporting tissue is bacterial consortia Treponema denticola, Tannerella forsythia, and Porphyromonas gingivalis, collectively referred to as the red complex. The red complex uses the common bacterial strategy of producing and embedding itself in extracellular polymeric substance, which contributes to the recalcitrance of periodontitis and was therefore of interest in this study. The red complex static cultures were grown in combination with different chemicals in order to establish what changes accompany these chemical challenges. This research established that extracellular polymeric substance carbohydrate yields increased with time. Interestingly, carbohydrate composition via gas chromatography-mass spectrometry analysis detected an increase of mannose and galactose in the samples challenged with tetracycline and decrease of these sugars in cultures challenged with hydrogen peroxide. Understanding the molecular features that contribute to biofilm formation in the red complex will offer unique insights into how bacteria communicate and thrive under various conditions and may provide strategies to mitigate periodontal disease. The results of this study have the potential to identify new mechanisms of biofilm establishment and persistence. These insights may ultimately lead to new methods to disrupt biofilm formation, which could benefit diverse sectors ranging from natural resource extraction, water resource management, and health.

Convocation Year


Convocation Season


Included in

Biochemistry Commons