Chemical and biological profiling on rhizobacteria from Physalis peruviana with antagonistic activity agaisnt Fusarium oxysporum

From Physalis peruviana rhizosphere were isolated 174 bacterial strains, which were tested for their in vitro antagonism against Fusarium oxysporum and their capability for promoting germination on P. peruviana seeds. From this set of rhizobacteria, 11 strains were found to have antagonistic activity and only 6 possessing effects on germination. In order to chemically characterize these strains, indole and alkylresorcinol quantification by colorimetric methods, as well as medium polarity metabolic profile from these antagonistic rhizobacteria by high resolution liquid chromatography coupled to mass spectrometry (HPLC-MS), were performed for bacterial cultures. All chemical and biological data were analyzed by multivariate statistics using principal component analysis (PCA). A close relationship was found between indole content and germination. In addition, antagonistic activity was correlated at different levels. Indole derivatives were found to be the most common compounds into the LC-MS profile in bacterial cultures.