Microbial Species Coexistence Depends on the Host Environment

摘要: Organisms and their resident microbial communities form a complex mostly stable ecosystem. It is known that the specific composition abundance of certain bacterial species affect host health fitness, but processes lead to these patterns are unknown. We investigate this by deconstructing simple microbiome freshwater polyp Hydra contrast performance its two main associates, Curvibacter Duganella, on germfree hosts with in vitro environments over time. show interactions within also environment observed frequencies abundances. More specifically, we find both can only stably coexist environment, whereas Duganella outcompetes irrespective initial starting frequencies. While seems benefit through secretions Curvibacter, competitive effect depends upon direct contact. The competition might potentially be mitigated spatial distribution host, which would explain why host. Interestingly, relative abundances do not match reported previously nor overall carrying capacity as study. Both observations indicate rare community members relevant for achieving native capacity. Our study highlights dissecting environmental conditions need replicated, goal difficult achieve systems.IMPORTANCE This work studies cnidarian investigates whether coexistence stability depend environment. outcome interaction between most dominant Hydra's differs depending results context. interactive ecology microbes, less abundant microbiome, critically important composition. indicates metaorganism needs taken into account when studying interactions.