Table 1.

Quorum sensing signaling molecules and phenotypes controlled in Gram-negative and Gram-positive bacteria.

Autoinducer(s)	Producing bacteria	Phenotype(s) controlled	Ref.
Gram-negative bacteria
N-acyl homoserine lactone (AHL)	V. fischeri, P. aeruginosa, C. violaceum, Aer. hydrophila	Bioluminescence, Exopolysaccharide production, Biofilm formation, Virulence factor, Pigmentation	30-35
Autoinducer-2 (AI-2)	V. harveyi, E. coli, Y. pestis	Bioluminescence, Biofilm formation, Motility, Virulence factor	36-39
4,5-dihydroxy-2,3-pentanedione	Sa. enteric serovar typhimurium	Virulence factor	40, 41
Cyclic dipeptides/ Diketopiperazines (DKP) (a) Cyclo(L-Pro-L-Tyr)	P. putida WCS358, P. aeruginosa	Cross activates QS biosensors	42, 43
(b) Cyclo(L-Phe-L-Pro)	P. putida WCS358, P. aeruginosa	Cross activates QS biosensors	42, 43
(c) Cyclo(L-Leu-L-Pro)	P. putida WCS358	Cross activates QS biosensors	42
(d) Cyclo(L-Leu-L-Val)	P. putida WCS358	Cross activates QS biosensors	42
Quinolone (2-heptyl-3-hydroxy-4-quinolone)	P. aeruginosa	Antibiotic production	44-46
Diffusible factor (DSF)	X. campestris	Endoglucanase production	47
Gram-positive bacteria
Autoinducing peptide (AIP1-AIP4)	Sta. aureus	Cross-signaling between strains and species, Biofilm formation, Virulence factor	28, 29, 48, 49