title: Oscillating microbial dynamics driven by small populations, limited nutrient supply and high death rates.
abstract: Predicting and controlling the behaviour of microbial ecosystems demands a fundamental understanding of the factors controlling their dynamics. In the natural environment microbes typically live in small local populations with limited and unpredictable nutrient supply and high death rates. Here, we show that these conditions can produce oscillations in microbial population dynamics, even for a single population. For a large population, with deterministic growth dynamics, our model predicts transient (damped) oscillations. For a small population, demographic noise causes these oscillations to be sustained indefinitely. We show that the same mechanism can produce sustained stochastic oscillations in a two-species, nutrient-cycling microbial ecosystem. Our results suggest that oscillatory population dynamics may be a common feature of small microbial populations in the natural environment, even in the absence of complex interspecies interactions or spatial structuring.
authors.affiliation: SUPA, School of Physics and Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK. bhavin.khatri@physics.org
authors.forename: Bhavin S
authors.initials: BS
authors.lastname: Khatri
authors.forename: Andrew
authors.initials: A
authors.lastname: Free
authors.forename: Rosalind J
authors.initials: RJ
authors.lastname: Allen
mesh_terms: D003198:Computer Simulation; D017753:Ecosystem; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development*; D005947:Glucose / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects*; D008954:Models, Biological; D013269:Stochastic Processes; D013997:Time Factors
chemical_list: D005947:Glucose