Table 1.

Four QQ approaches were used to alleviate the effects of QS against pathogenic bacteria

Approaches of QQ		Enzyme type	Origin	Expression strains	Application and references
Purified QQ enzymes	AidP	AHL lactonase	Planococcus sp.	E. coli BL21	AidP attenuated the pathogenicity of P. carotovorum in Chinese cabbage [2]
	MomL	AHL lactonase	M. olearia Th120	E. coli BL21(DE3)	MomL attenuated virulence of P. aeruginosa in a Caenorhabditis elegans infection mode [17]
	AiiK	AHL lactonase	K. huakuii	E. coli BL21(DE3)	AiiK inhibited biofilm formation and attenuated extracellular proteolytic activity and pyocyanin production of P. aeruginosa PAO1 [18]
	RmmL	AHL lactonase	R. mobilis YJ3	E. coli BL21(DE3)	RmmL reduced pyocyanin production of P. aeruginosa PAO1 and extracellular protease activity of V. anguillarum VIB72 [19]
	AiiAQSI-1	AHL lactonase	Bacillus sp. QSI-1	E. coli BL21(DE3)	AiiAQSI-1 inhibited swimming motility, extracellular protease, hemolysin factor, and biofilm formation of A. hydrophila YJ-1 [20]
	AiiAB546	AHL lactonase	Bacillus sp. B546	P. pastoris	AiiAB546 decreased mortality rate and delayed mortality time of fish when co-injection with A. hydrophila in common carp [21]
Expressed QQ enzymes in pathogenic bacteria	AiiA	AHL lactonase	Bacillus sp. 240B1	E. carotovora stain SCG1	The introduction of aiiA gene in E. carotovora stain SCG1 decreased extracellular pectolytic activities and pathogenicity of E. carotovora [22]
	AiiM	AHL lactonase	M. testaceum StLB037	P. c. c. NBRC 3830	The introduction of aiiM gene in P. carotovorum subsp. carotovorum NBRC 3830 attenuated soft rot symptoms on potato slices [23]
	AttM	AHL lactonase	A. tumefaciens c58	S. scabies	The introduction of attM gene suppressed pathogenicity of S. scabies towards potato tuber [24]
	HqiA	AHL lactonase	Metagenomic library from soil	P. c. c. CECT 225T	The introduction of hqiA gene in plant pathogen P. carotovorum efficiently interfered swarming motility and maceration enzymes production [25]
Isolated and identified new QQ strains	B. licheniformis T-1	AHL lactonase	Freshwater culture pond sediment	No	B. licheniformis T-1 reduced pathogenicity of A. hydrophila cb15 in zebrafish coinjection [12]
Constructed recombinant QQ strains	BbMomL	AHL lactonase	M. olearia Th120	B. brevis	BbMomL reduced secretion of pathogenic factors and pathogenicity of P. carotovorum subsp. carotovorum and P. aeruginosa PAO1 [26]
	LcAiiK	AHL lactonase	K. huakuii	L. casei MCJΔ1	LcAiiK attenuated swimming motility, virulence factor production, and biofilm formation of A. hydrophila AH-1 and AH-4 (This study)