The deferred growth inhibition assay can be used to assess the competition effect by one bacterial isolate on another. Inhibition is quantified by measuring the zone of clearing around the inhibitor-producing isolate, or qualitatively assessed by determining the visible extent of inhibition.
Moran, J. C., Crank, E. L., Ghabban, H. A., Horsburgh, M. J. Deferred Growth Inhibition Assay to Quantify the Effect of Bacteria-derived Antimicrobials on Competition. J. Vis. Exp. (115), e54437, doi:10.3791/54437 (2016).