Erwinia psidii

Erwinia psidii is a Gram-negative bacillus and a phytopathogen of the guava (Psidium guajava), causing rot in branches, flowers and fruits. Recently, it was demonstrated that this species produces two acyl-homoserine lactones (S-(-)-N-hexanoyl- and N-heptanoyl-homoserine lactone), widely recognized bacterial quorum sensing signaling substances, and employed in bacterial cell-to-cell communication systems.