In the search for new organisms and new secondary metabolites, a study was conducted
to evaluate the diversity of endophytic bacteria from ethnovarieties of cassava cultivated by Brazilian
Amazon Indian tribes and also to study the secondary metabolites produced by a Bacillus pumilus
strain. Sixty seven cassava endophytic bacteria were subjected to 16S rRNA sequencing and FAME
analysis. The bacterial profile revealed that 25% of all endophytic isolates belonged to the genus
Bacillus. The isolate B. pumilus MAIIIM4a showed a strong inhibitory activity against the fungi
Rhizoctonia solani, Pythium aphanidermatum and Sclerotium rolfsii. Secondary metabolites of this
strain were extracted using hexane, dichloromethane and ethyl acetate. Extracts were subjected to
bioautography and LC/MS analysis, which allowed the identification of pumilacidin, an antifungal
compound produced by B. pumilus MAIIIM4a. The bacterial endophytic localization was confirmed
by cassava cell tissue examination using scanning electron microscopy.
Key words: ESI-MS/MS, pumilacidin, endophytic bacteria, bioautograph