Figure 2.

Selected molecular determinants of inter-bacterial interactions. Beneficial interactions include the exchange of material such as outer membrane components, metabolites or intracellular content and the transfer of plasmid DNA to recipient cells by conjugation. Biofilm formation and cell aggregation involve many determinants such as exopolysaccharides and Type IV pili, and allow an increased protection against antibiotics or physical stresses. Bacterial competition involves the release of antagonistic molecules, peptides and proteins or the direct delivery of toxin effectors by dedicated machineries, such as Type VI secretion and contact-dependent growth inhibition systems.