Figure 4.

TLC analysis of AHL samples extracted from cultures of strain DC283 (wild type), and mutant strains ESΔR, ESΔIR, and ESN51. The lane designated STD contains synthetic preparations of N-3-oxoacyl-HSLs identified by their respective acyl side chains. The standards included 0.52 pmol of 3-oxo-C6-HSL, 0.03 pmol of 3-oxo-C8-HSL, 3 pmol of 3-oxo-C10-HSL, and 16 pmol of 3-oxo-C12-HSL. AHLs were detected only in cultures of strains DC283 and ESΔR. All samples applied were extracted from cultures grown to an OD₅₆₀ of 0.6 and concentrated about 20-fold.