You Talking to Me? Quorum Sensing in Symbiotic Microbes and Their Response to Environmental Variation

Bacterial communication or quorum sensing (QS) is a common yet complex system where multiple factors influence the extent to how this chemical dialog is transferred from a single clone to the larger community of microbes in the population. More often, when bacteria are in large concentrations, their genetic and subsequent biochemical response to different chemical cues is influenced by not only which microorganisms are present but also the environmental variables that surround those individuals. This is especially relevant when symbiotic bacteria are dependent upon host functions yet are in high enough concentrations that can manifest their own behaviors in response to the present host prior, during, and after colonization. This review will examine the various abiotic and biotic factors that regulate QS when bacteria are in the process of detecting, colonizing, and persisting in a host that uptakes its microbial partner from the environment, as well as the consequences of multiple stressors on this dynamic communication process.