Vannini L, Ndagijimana M, Saracino P, Vernocchi P, Corsetti A, Vallicelli M, Cappa F, Cocconcelli PS, Guerzoni ME. New signaling molecules in some gram-positive and gram-negative bacteria. International Journal of Food Microbiology. 2007 Nov;120(1-2):25–33. doi: 10.1016/j.ijfoodmicro.2007.02.028.