Fig. S1. Optimization of the LC/ESI-MS/MS method used for detection and quantification of surfactin. Full-scan ESI-MS spectrum in positive mode of a 0.01 μM of a solution of commercial surfactin eluted at 2.69 min. Inset, The main parental peak mass [M + H]+ at 1036 (m/z) was analysed using a LC/ESI-MS/MS in selected reaction monitoring (SRM) mode and was derived into two ions: 685.5 [M + H]+ for quantification and 227 [M + H]+ for quality.


Fig. S2. Estimation of the amount of surfactin produced by B. subtilis UMAF6614 on melon leaves. Extracts from melon leaves were analysed for the presence of surfactin using the LC/ESI-MS/MS in SRM mode method optimized with commercial surfactin. The main parental mass [M + H]+ at 1036 (m/z) of the eluent at 2.69-2.72 min and corresponding to surfactin was derived into two ions: 685.5 [M + H]+ for quantification and 227 [M + H]+ for quality of the analysis.

A. Leaves treated with wild-type UMAF6614 strain.

B. srfAB supplemented with commercial surfactin.

Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.