Siderophore-mediated iron partition promotes dynamical coexistence between cooperators and cheaters

Abstract

Microbes shape their habitats through consuming resources, as well as actively producing and secreting diverse chemicals. These chemicals serve various niche-construction functions and can be considered "public good" for the community. Most microorganisms, for instance, release small molecules known as siderophores to scavenge irons from the extracellular environment. Despite being exploitable by cheaters, biosynthetic genes producing such molecules widely exist in nature, invoking active investigation on the possible mechanisms for producers to survive cheater invasion. In this work, we utilized the chemostat-typed model to demonstrate that the division of the iron by private and public siderophores can promote stable or dynamical coexistence between the cheater and "partial cooperators", an adaptive strategy with the production of both public and private siderophores. Further, our analysis revealed that when microbes not only consume but also produce resources, this type of "resource partition model" exhibit different stability criteria than that of the classical consumer resource model, allowing more complex systems dynamics.