Modeling Bacterial Pathogen/Biocontrol Competition With Changing Temperature

This proposal addresses the President's National Food Safety Initiative to predict and prevent the growth of harmful bacteria in foods. The foods we eat, including fresh fruits and vegetables, contain bacteria. When disease-causing bacteria grow in foods, they must compete with naturally present (generally harmless) bacteria. Current models for bacterial growthin foods do not take into account this microbial competition. Our project is unique in modeling competition between microorganisms. We are developing models for the growth and death of two or more competing microorganisms during changing environmental conditions. This project involves a multi-disciplinary approach to study the competition of microorganisms in foods, including biochemistry, microbiology, mathematics and computer simulation models. The computer simulations and mathematical models being developed will be used primarily as tools to investigate the mechanisms of microbial competition. These models will be validated by experimental observations. One objective of this project is to develop biocontrol strategies for producing safe food products. Our biocontrol approach uses safe bacteria(which are normally used in food fermentations) as food additives; they will be selected for their ability to compete with, and prevent the growth of, pathogens in foods. It is hoped that the principles learned in these studies can be applied to the prediction and prevention of the growth of disease causing bacteria in a variety of foods.