Avaliação química de Bacillus spp e Azospirillum spp com aplicação na bananicultura

Abstract

Bacteria of the genus Bacillus and Azospirillum are well-know to have applications in the agroindustry for the production of bioactive substances that act in the combat against crop pests, in addition to the production of a wide variety of lipopeptides with antifungal function. In this context, this work aims to evaluate the chromatographic profile, in order to identify bioactive secondary metabolites, in addition lipopeptides, in the cell-free fermentation broth of strain Bacillus cereus, B. pumilus, B. safensis, B. stratosphericus, B. subtilis, and Azospirillum brasilense. For this, the sample obtained were subjected to liquid-liquid partition and acid precipitation, later, to ultra-performance liquid chromatography coupled with mass spectrometer and diode array detector (UPLC/QDA). The samples were also analyzed by 1H Nuclear Magnetic Resonance (NMR). The chemical investigation resulted in the indentification of 9 metabolites, cyclic(D-Pro-D-Leu), cyclic(D-Trp-L-Pro), cyclic(L-Pro-L-Val), cyclic(L-Pro-D-Phe), phosphatidylethanolamine, 2,4-dihydroxy-7-methoxy-2H-1,4-benzoaxy-3H(4H)-one, 2-nonyl-4-hydroxyquinoline N-oxide, lipoamide B, hydroxypalmitoyl sphinganine, previously reported in the literature and in the observation, from the ion monitoring mode (SIM), of 6 peaks in the chromatograms referring to fengycin A and B. The presence of fengycins was confirmed by 1H NMR spectra. Evidencing, from these studies, the presence of molecules with antifungal properties in the strains, with promising application in the banana market.