Using Coculture to Detect Chemically Mediated Interspecies Interactions

The overall goal of the following experiment is to identify interactions between different microbes that are mediated by secreted compounds and lead to changes in bacterial gene expression. This is achieved by culturing of bacterial strain containing a fluorescent transcriptional reporter with environmental microbes as colonies on agar Petri plates. The orange circles represent colonies of the environmental microbes.

While the blue circles are colonies of the reporter, growth on solid media allows the metabolites that these colonies produce to diffuse through the agar and activate gene expression in nearby reporter colonies. The potential hits indicated here with stars are those colonies that may be secreting compounds that alter gene expression in the reporter. These organisms are isolated from the co-culture screen plates.