A community model of ciliate Tetrahymena and bacteria E-coli .2. Interactions in a batch system

Authored by JS Jaworska, TG Hallam, TW Schultz

Date Published: 1996

Sponsors: United States Environmental Protection Agency (EPA) Oak Ridge National Laboratory (ORNL)

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

Premised on relatively simple assumptions, mathematical models like those of Monod, Pirt or Droop inadequately explain the complex transient behavior of microbial populations. In particular, these models fail to explain many aspects of the dynamics of a Tetrahymena pyriformis-Escherichia coli community. In this study an alternative approach, an individual-based model, is employed to investigate the growth and interactions of Tetrahymena pyriformis and E. coli in a batch culture. Due to improved representation of physiological processes, the model provides a better agreement with experimental data of bacterial density and ciliate biomass than previous modeling studies. It predicts a much larger coexistence domain than rudimentary models, dependence of biomass dynamics on initial conditions (bacteria to ciliate biomasses ratio) and appropriate timing of minimal bacteria density. Moreover, it is found that accumulation of E. coli sized particles and E. coli toxic metabolites has a stabilizing effect on the system.

Tags

Dynamics Coexistence population Prey Escherichia-coli Predators Pyriformis Protozoa Wall growth Thermophila