Seleção de bactérias endofíticas amazônicas produtoras de lipopeptídeos bioativos

Abstract

The endophytic microrganisms, particularly bacteria and fungi live in the plants, including thein roots apparently cause no harm. Bacteria and fungi are potentially useful in agriculture and industry, particularly in the food and pharmaceutical industries, as they produce different chemical classes and can participate in various industrial biotechnological processes. Among the compounds produced by bacteria, lipopeptides belong to a class that has attracted great interest for its antifungal, antibiotic and surfactant among others. In this stud 50 strains were selected of Amazonian endophytic bacteria for antimicrobial evoluction and the production of lipopeptides by ESI-ITMS2. Of these, 25 strains produced lipopeptides, six plant isolated from Gustavia genus, nine Macrophyte, five Duguetia, one Pothomorpha, two Rollina and one Bryophyllum. The fragmentation analysis by ESI-MS2 in negative mode identified eight extracts the lipopeptide surfactin homologs of C11 - C18, including C11, C17 and C18 not been reported in the literature. In biological assays paired cultures, 48 strains showed mycoparasitism antimicrobial activity against Gram-negative bacteria P. aeruginosa and E. coli, 27 strains against Gram-positive bacteria S. aureus, E. faecalis, 29 strains against and 28 against C. albicans, also presenting competition activity against E. faecalis 21 strains and C. albicans strains against 23 S. aureus strains and 2 against P.aeruginosas and E. coli. No strain with antibiotic activity observed. In assessing the bioactivity of lipopeptide extracts, 13 of the extracts strains showed antibiosis against S. aureus, P. aeruginosa and C.albicans.