TABLE 4.

Mass spectrometric identification of AHLs secreted by S. meliloti 8530 and sinI and expR mutant strains

AHL	Relative responsea						HPLC fractions
	8530		expR		sinI
	GC/MS	ESI/MS/MS	GC/MS	ESI/MS/MS	GC/MS	ESI/MS/MS
C16	1.0	1.0	1.0	1.0	0	0	43-46
3-Oxo-C14	2	0.5	0.3	0.1	0	0	33-36
C16:1	2	1	0.5	2	0	0	37-39
3-Oxo-C16	0.5	0.2	0.3	1	0	0	37-39
3-Oxo-C16:1	80	8	30	7	0	0	33-36

^aAmount of AHL detected relative to C₁₆-HSL.