Graduate School of Life Science, Hokkaido University, Hokkaido, Japan; Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN, Saitama, Japan.
Faculty of Advanced Life Science, Hokkaido University, Hokkaido, Japan; Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.
J Theor Biol. 2023 Sep 21;573:111597. doi: 10.1016/j.jtbi.2023.111597. Epub 2023 Aug 19.
Many researchers have studied the population dynamics of microbe of microbes as a typical example of population dynamics. The Monod equation, which mainly focuses on the growth and stationary phases, is used when plotting a growth curve. However, the growth potential in the late stage of culture has been overlooked. Previous studies considered the direct degradation of products to the limiting substrate. In this study, we considered microbial growth during the stationary phase, which enables us to describe the dynamics precisely. The microbes were divided into two populations: one grew by consuming the limiting substrate and the other degraded the products by metabolism. According to the numerical analysis of our model, microbes may choose one of two strategies: one consumes substrates and expands quickly, and the other grows slowly while cleaning up the environment in which they thrive. Furthermore, we found three types of microbial growth depending on their ability to detect metabolite accumulation. Using experimentally measured data, this model can estimate the dynamics of cell density, the substrates, and the metabolites used. The model's disentangling of growth curves offers novel interpretive possibilities for culture system dynamics.
许多研究人员已经研究了微生物种群动态，将其作为种群动态的典型例子。在绘制生长曲线时，主要使用莫诺德方程（Monod equation），该方程主要关注生长和静止阶段。然而，培养后期的生长潜力却被忽视了。以前的研究认为产物的直接降解是对限制底物的降解。在这项研究中，我们考虑了微生物在静止期的生长，这使我们能够更准确地描述动态。微生物被分为两个种群：一个种群通过消耗限制底物来生长，另一个种群通过代谢来降解产物。根据我们模型的数值分析，微生物可能会选择两种策略之一：一种是快速消耗底物并快速扩张，另一种是缓慢生长，同时清理它们赖以生存的环境。此外，我们发现了三种类型的微生物生长，这取决于它们检测代谢物积累的能力。使用实验测量的数据，该模型可以估计细胞密度、底物和使用的代谢物的动态。该模型对生长曲线的分解为培养系统动态提供了新的解释可能性。
