Coexistence of Competing Microbial Strains under Twofold Environmental Variability and Demographic Fluctuations
Coexistence of Competing Microbial Strains under Twofold Environmental Variability and Demographic Fluctuations
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DOI：
10.1088/1367-2630/ad0d36
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发表时间：
2023-12-01
影响因子：
3.3
通讯作者：
Mobilia，Mauro
中科院分区：
文献类型：
--
作者：
Asker，Matthew;Hernandez-Navarro，Lluis;Mobilia，Mauro
微生物种群通常在不稳定的环境中进化，条件在苛刻和温和之间波动，例如毒素浓度或营养丰富度的突然变化。因此，环境变异性（EV）塑造了长期的种群动态，特别是通过影响不同菌株的微生物共存的能力。受抗生素耐药性演变的启发，我们研究了由两种竞争菌株组成的社区的动态，以双重EV。毒素水平随时间变化，有利于一种菌株在低药物浓度下生长，而另一种菌株在毒素水平高时生长。我们还通过随机切换承载能力来模拟随时间变化的资源丰度，该承载能力驱动了社区规模的波动。虽然一个菌株占主导地位的静态环境中，我们表明，种共存是可能的EV的存在。通过计算和分析手段，我们确定的环境条件下，长期共存是可能的，当它几乎是肯定的。值得注意的是，我们研究的情况下，环境和人口的波动促进，或阻碍，菌株共存。我们还确定了如何组成的共存相和每个菌株的平均丰度取决于EV。
Microbial populations generally evolve in volatile environments, under conditions fluctuating between harsh and mild, eg as the result of sudden changes in toxin concentration or nutrient abundance. Environmental variability (EV) thus shapes the long-time population dynamics, notably by influencing the ability of different strains of microorganisms to coexist. Inspired by the evolution of antimicrobial resistance, we study the dynamics of a community consisting of two competing strains subject to twofold EV. The level of toxin varies in time, favouring the growth of one strain under low drug concentration and the other strain when the toxin level is high. We also model time-changing resource abundance by a randomly switching carrying capacity that drives the fluctuating size of the community. While one strain dominates in a static environment, we show that species coexistence is possible in the presence of EV. By computational and analytical means, we determine the environmental conditions under which long-lived coexistence is possible and when it is almost certain. Notably, we study the circumstances under which environmental and demographic fluctuations promote, or hinder, the strains coexistence. We also determine how the make-up of the coexistence phase and the average abundance of each strain depend on the EV.