The Impact of Variable Stoichiometry on Predation and Competition: Development of Microbial Experimental Models

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

The impact of variable stoichiometry on predation and competition: development of microbial experimental models. James P. Grover University of Texas at Arlington This project will address how variations in the chemical composition ("stoichiometry") of microorganisms affect their interactions with other species. In theory, variations in composition of the nutrient elements carbon, nitrogen, and phosphorus, affect competition between bacterial species, and also affect the relationship of bacterial prey with the larger microorganisms that consume them. Recently developed mathematical simulation models of these processes will be tested using laboratory cultures of two bacterial species and a consumer microorganism. Some specific predictions to be tested include the proposal that the capability to reduce the cellular content of a nutrient indicates efficient nutrient use and can improve a species' competitive ability, the proposal that consumers alter the outcome of competition between prey species, and the notion that this effect depends on details of chemical composition and the processing and recycling of nutrients on the part of the consumer. This project will provide research training for graduate and undergraduate students, including those recruited from under-represented groups. It will also provide insights into processes governing abundances of microorganisms in nature, including some species of "harmful algae" whose lifestyle includes feeding upon bacteria.