Antagonism and Antimicrobial Capacity of Epiphytic and Endophytic Bacteria against the Phytopathogen Xylella fastidiosa

Olive quick decline syndrome (OQDS), which is caused by Xylella fastidiosa, poses a severe threat to the agriculture of Mediterranean countries and causes damage olive trees in Italy. Since no effective control measures are currently available, objective this study was screening antagonistic bacteria that potentially deployable as biocontrol agents against X. fastidiosa. Therefore, two approaches were used, i.e., evaluation activity (i) endophytic isolated from different cultivars (Leccino Ogliarola salentina) (ii) epiphytic phyllospheres host plant species In vitro dual culture tests showed 12 out 200 isolates inhibited fastidiosa growth, with appearances clear zones between 4.0 38.6 mm. 16S rRNA gene sequencing revealed genera Paenibacillus, Bacillus, Pantoea, Microbacterium, Stenotrophomonas, Delftia, Pseudomonas. Furthermore, an investigation for antimicrobial identified 5 bacteria, Paenibacillus rigui, Bacillus subtilis, pumilus, Microbacterium oxydans, Stenotrophomonas rhizophila, able produce filtrates inhibitory activities. Our results promising further develop eco-sustainable strategy using or their secreted metabolites.