Influence of phenolic acids on indole acetic acid production and on the type III secretion system gene transcription in food-associated Pseudomonas fluorescens KM05

• Reduction effect of phenolics on indole acetic acid synthesis of cells was tested.
• Specific genetic primer for TTSS system in P. fluorescens KM05 was designed.
• Effect between indole acetic acid synthesis and TTSS gene expression was tested.
• Ferulic and chlorogenic acids suppressed P. fluorescens KM05 signaling.
• Ferulic and chlorogenic acids are promising interferers of bacterial virulence.

The purpose of these investigations was to evaluate the reduction capability of phenolic acids (ferulic, chlorogenic, gallic, and p-coumaric acids) on indole acetic acid synthesis by food-associated Pseudomonas fluorescens KM05. Specific genetic primer for the type III secretion system (TTSS) in P. fluorescens KM05 was designed and the influence of phenolic acids on its expression was investigated. In the work the ferulic and chlorogenic acids at the concentration of 0.02 and 0.04 μg/ml affected on bacterial growth pattern and the signal molecules production. The phenolic acids, that were appreciable effective against P. fluorescens KM05 indole acetic acid production, significantly suppressed TTSS gene.