Although being widespread and highly diverse, the biological roles of most bacterial volatiles are yet to be discovered. This study describes the activity of a low-weight volatile compound, 2-aminoacetophenone (2-AA), produced by Pseudomonas aeruginosa and other bacterial species. We found that Pseudomonas aeruginosa`s total volatiles activated the LuxR quorum sensing (QS) response regulator of Vibrio fischeri in genetically modified bioreporter strains. Comparative Gas-chromatograph analyses between P. aeruginosa wild type and mutant strains indicated that the LuxR activating compound is 2-AA. Use of synthetic 2-AA, its chemical analogues and in silico docking analyses verified the activity of 2-AA towards LuxR, and suggested that the amino- and the ketone groups of 2-AA are crucial in LuxR-2-AA interaction. Addition of 2-AA to V. fischeri wild type culture also resulted in an induction of QS-regulated luminescence, indicating that 2-AA could serve as inter-species signal interfering in QS-regulated pathways. Further studies will be conducted in order to evaluate the importance of 2-AA-mediated inter-species interactions within bacterial communities.
