SUPA, School of Physics and Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK.
J Theor Biol. 2012 Dec 7;314:120-9. doi: 10.1016/j.jtbi.2012.08.013. Epub 2012 Aug 21.
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.
预测和控制微生物生态系统的行为需要对控制其动态的因素有一个基本的了解。在自然环境中，微生物通常生活在小的局部种群中，营养供应有限且不可预测，死亡率高。在这里，我们表明，即使对于单个种群，这些条件也可以产生微生物种群动态的振荡。对于具有确定性增长动态的大种群，我们的模型预测了瞬态（阻尼）振荡。对于小种群，人口统计学噪声导致这些振荡无限期持续。我们表明，相同的机制可以在具有营养循环的两种微生物生态系统中产生持续的随机振荡。我们的结果表明，振荡的种群动态可能是自然环境中小微生物种群的一个共同特征，即使在没有复杂的种间相互作用或空间结构的情况下也是如此。
