Is population-level heterogeneity a reflection of distinct subpopulations, exhibiting different metabolic functions, or dynamic metabolism of individuals within the population? This fascinating question has remained a subject of great interest in studying metabolic specialization in microorganisms. The Crabtree effect – i.e., the ability of some microorganisms to switch from respiration to fermentation in the presence of oxygen - is an appropriate case study to address the aforementioned question. Game-theoretical approaches have been routinely used to examine and explain the way a microorganism, such as yeast, would switch between the two ATP-producing pathways, i.e., respiration and fermentation. Here we attempt to explain the switch between respiration and fermentation in yeast by constructing a simple metabolic switch. We then utilize an individual-based model, in which each individual is equipped with all the relevant chemical reactions, to see how cells equipped with such metabolic switch would behave in different conditions. We further investigate our proposed metabolic switch using the game-theoretical approach. Based on this model, we postulate that the population-level metabolic heterogeneity in microorganisms can simply arise from individuals utilizing a mixed strategy.

种群水平的异质性是不同亚种群的反映，表现出不同的代谢功能，还是种群内个体的动态代谢？这个引人入胜的问题一直是研究微生物代谢专业化的一个非常感兴趣的主题。Crabtree 效应——即一些微生物在有氧的情况下从呼吸转变为发酵的能力——是解决上述问题的一个合适的案例研究。博弈论方法已常规用于检查和解释微生物（如酵母）在两种 ATP 产生途径（即呼吸和发酵）之间切换的方式。在这里，我们试图通过构建一个简单的代谢开关来解释酵母中呼吸和发酵之间的转换。然后，我们利用基于个体的模型，其中每个个体都配备了所有相关的化学反应，以查看配备这种代谢开关的细胞在不同条件下的行为。我们使用博弈论方法进一步研究了我们提出的代谢转换。基于该模型，我们假设微生物中种群水平的代谢异质性可以简单地由个体利用混合策略产生。