On-line visualization of the competitive behavior of antagonistic bacteria.

To study the interaction between cocultured Listeria monocytogenes and an antagonistic Leuconostoc strain producing an anti-Listeria bacteriocin, flow cytometry, a technique allowing on-line and real-time analysis, was used along with classical microbiological methods. Culture methods and flow cytometric measurements of the mixed culture over time point to a bactericidal action of the lactic acid-producing bacterial strain against L. monocytogenes cells.