Poster Title
Competive Exclusion Dynamics of S. typhimurium and S. flexinari for the Carbon Source Sorbitol
Faculty Advisor
Josey Barton
Department
Biology
Abstract
Enteric bacteria are a group of Gram-negative small-rod bacteria that colonize the gastrointestinal (GI) tract in humans and animals (Madigan et al. 2005). In order to thrive in the GI tract, bacteria need a carbon source to grow and multiply. Sorbitol, a sugar alcohol derived from glucose, is commonly used as a carbon source. According to Hibbing et al. (2010) the competitive exclusion principle states that competition between organisms leads to decreased population densities for both organisms, and one organism will eventually dominate. In this study we examined competition for the carbon source sorbitol between the enteric bacteria Salmonella typhimurium and Shigella flexneri. The species capable of utilizing sorbitol more efficiently will outcompete the other organism for available nutrients. Carbon source utilization is determined by the genes the organism possesses; Salmonella typhimurium contains the enzyme Sorbitol-6-Phosphate Dehydrogenase (Berkowitz 1970) which allows it to efficiently utilize sorbitol as a carbon source.
Hypothesis:
When placed in direct competition with each other for minimal nutrients with sorbitol as the predominant carbon source, we predict S. typhimurium will outcompete S. flexneri due to its specialized enzyme.
Start Date
19-4-2012 11:00 AM
End Date
19-4-2012 1:00 PM
Competive Exclusion Dynamics of S. typhimurium and S. flexinari for the Carbon Source Sorbitol
Enteric bacteria are a group of Gram-negative small-rod bacteria that colonize the gastrointestinal (GI) tract in humans and animals (Madigan et al. 2005). In order to thrive in the GI tract, bacteria need a carbon source to grow and multiply. Sorbitol, a sugar alcohol derived from glucose, is commonly used as a carbon source. According to Hibbing et al. (2010) the competitive exclusion principle states that competition between organisms leads to decreased population densities for both organisms, and one organism will eventually dominate. In this study we examined competition for the carbon source sorbitol between the enteric bacteria Salmonella typhimurium and Shigella flexneri. The species capable of utilizing sorbitol more efficiently will outcompete the other organism for available nutrients. Carbon source utilization is determined by the genes the organism possesses; Salmonella typhimurium contains the enzyme Sorbitol-6-Phosphate Dehydrogenase (Berkowitz 1970) which allows it to efficiently utilize sorbitol as a carbon source.
Hypothesis:
When placed in direct competition with each other for minimal nutrients with sorbitol as the predominant carbon source, we predict S. typhimurium will outcompete S. flexneri due to its specialized enzyme.
Comments
This poster was a part of the Biology of Microorganisms class in which students performed independent semester-long research projects. The study ideas were thought up by the student research groups. No funding is available in the department to print these posters since all funding was used for supply resources.