IADR Abstract Archives
Streptococcus mutans and Bacillus subtilis Inter-relationship During Biofilm Formation
Objectives: Bacterial interactions often result in formation of complex structural communities termed biofilms .Biofilm formation represents the first and main step in the development and progression of the majority of oral disorders. Streptococcus mutans and Bacillus subtilis have been both extensively studied individually as model bacteria for robust biofilm formation. While S. mutans is a leading cause of dental disorders, B. subtilis is considered non-pathogenic food-borne bacterium, which recently has been isolated from the oral cavity. The aim of this research is to investigate the effect of different dietary sugars on the interaction between S. mutans and B. subtilis during dual-biofilm formation.
Methods: S. mutans and B. subtilis cells were grown in co-culture in the presence of different dietary sugars as sucrose, lactose, glucose, mannitol, xylitol and sorbitol. The effect of the sugars on bacterial physiology was determined in terms of their growth, metabolic activity and their ability to form biofilm. The generated biofilms were examined for biofilm biomass as well as structure.
Results: Our results show that growth and metabolic activities of each bacterium are notably low in single culture. Whereas, in combined culture, B. subtilis and S. mutans facilitated each other growth and proliferation in the presence of non-alcoholic sugars as the only carbon source. Moreover, we found that sucrose and lactose are capable of promoting the dual-species biofilm formation. Using CLSM we demonstrated that B. subtilis cells are able to attach to the EPS formed by S. mutans. However, surprisingly, biofilm formation by S. mutans was dramatically decreased when both species were grown in co-culture in the presence of tested alcoholic sugars.
Conclusions: Our findings indicate that B. subtilis and S. mutans contribute to a mutual metabolism of non-alcoholic sugars and forming dual-species biofilm. However, B. subtilis cells can inhibit biofilm formation by S. mutans in the presence of alcoholic sugars.
Methods: S. mutans and B. subtilis cells were grown in co-culture in the presence of different dietary sugars as sucrose, lactose, glucose, mannitol, xylitol and sorbitol. The effect of the sugars on bacterial physiology was determined in terms of their growth, metabolic activity and their ability to form biofilm. The generated biofilms were examined for biofilm biomass as well as structure.
Results: Our results show that growth and metabolic activities of each bacterium are notably low in single culture. Whereas, in combined culture, B. subtilis and S. mutans facilitated each other growth and proliferation in the presence of non-alcoholic sugars as the only carbon source. Moreover, we found that sucrose and lactose are capable of promoting the dual-species biofilm formation. Using CLSM we demonstrated that B. subtilis cells are able to attach to the EPS formed by S. mutans. However, surprisingly, biofilm formation by S. mutans was dramatically decreased when both species were grown in co-culture in the presence of tested alcoholic sugars.
Conclusions: Our findings indicate that B. subtilis and S. mutans contribute to a mutual metabolism of non-alcoholic sugars and forming dual-species biofilm. However, B. subtilis cells can inhibit biofilm formation by S. mutans in the presence of alcoholic sugars.