Quantifying the strength, sign, and origin of species interactions, along with their dependence on environmental context, is at the heart of prediction and understanding in ecological communities. Pairwise interaction models like Lotka-Volterra provide an important and flexible foundation, but notably absent is an explicit mechanism mediating interactions. Consumer-resource models incorporate mechanism, but describing competitive and mutualistic interactions is more ambiguous. Here, we bridge this gap by modeling a coarse-grained version of a species’ true cellular metabolism to describe resource consumption via uptake and conversion into biomass, energy, and byproducts. This approach does not require detailed chemical reaction information, but it provides a more explicit description of underlying mechanisms than pairwise interaction or consumer-resource models. Using a model system, we find that when metabolic reactions require two distinct resources we recover Liebig’s Law and multiplicative co-limitation in particular limits of the intracellular reaction rates. In between these limits, we derive a more general phenomenological form for consumer growth rate, and we find corresponding rates of secondary metabolite production, allowing us to model competitive and non-competitive interactions (e.g., facilitation). Using the more general form, we show how secondary metabolite production can support coexistence even when two species compete for a shared resource, and we show how differences in metabolic rates change species’ abundances in equilibrium. Building on these findings, we make the case for incorporating coarse-grained metabolism to update the phenomenology we use to model species interactions.

量化物种相互作用的强度，标志和起源，以及它们对环境环境的依赖性，是生态社区预测和了解的核心。诸如Lotka-Volterra之类的成对交互模型提供了重要而灵活的基础，但值得注意的是，没有一种明确的机制可以介导交互。消费者资源模型包含机制，但是描述竞争性和互惠性的交互则更加模棱两可。在这里，我们通过模拟物种真实细胞代谢的粗粒度版本来描述通过摄入和转化为生物质，能量和副产物的资源消耗，从而弥合这一差距。这种方法不需要详细的化学反应信息，但是与成对交互或消费者资源模型相比，它提供了对底层机制的更明确的描述。使用模型系统，我们发现当代谢反应需要两种截然不同的资源时，我们恢复了李比希定律和乘性共限制，特别是细胞内反应速率的限制。在这些限制之间，我们得出了消费者增长率的更一般的现象学形式，并且我们找到了相应的次级代谢产物产生速率，从而使我们能够建模竞争性和非竞争性相互作用（例如促进）。使用更一般的形式，我们展示了即使两个物种竞争共享资源，次级代谢产物的生产也可以如何支持共存，并且我们展示了代谢率的差异如何改变物种的平衡状态。基于这些发现，