FIG. 5.

Analysis of the N-acyl-HSL produced by B. cepacia K56-2. (A) HPLC analysis of a culture fluid extract (○) and synthetic N-octanoyl-HSL (•). HPLC conditions are described in Materials and Methods. Each fraction was 1 ml. Activity was measured by the R. solanacearum reporter system. The solid line indicates methanol concentration. (B) Analysis of purified B. cepacia N-acyl-HSL (top) and synthetic octanoyl-HSL (bottom) by GC-MS. The m/z of the molecular ion was 227 for both, as expected for N-octanoyl-HSL. The molecular ion at 227 is amplified 10-fold (10×).