The development of food production in Brazil indicates a possible increase for the next years,
and would significantly influence national economy. Traditional crop management through the
use of agrochemicals generates a decrease in the crop pests but impair the quality of food.
Aiming at this problem, research have been carried out in search of biomolecules that can
replace agrochemicals. Several studies show that compounds secreted by bacteria have such
potential for inhibition against phytopathogenic fungi. The objective of this study was to isolate
and identify the major secondary metabolite, secreted by the bacterium Bacillus
amyloliquefaciens, that causes inhibition in the growth of the filamentous fungus. This work
also evaluated the behavior of the bacterium Bacillus amyloliquefaciens against the fungi
Trichoderma reesei QM9414, Candida spp. and selected phytopathogenic fungi such as
Fusarium graminearum, F. oxysporum, F. verticillioides, Bothrytis and Aspergillus flavus. The
supernatant of B. amyloliquefaciens growth medium was spread on PDA culture media (2, 4,
6, 8 and 10 μL) and showed the antifungal action against Trichoderma reesei QM9414 in all
volumes tested. Analysis of the simultaneous growth of B. amyloliquefaciens against
phytopathogenic fungi in media BDA showed that the secreted compound causes inhibition in
the fungi forming a halo around the bacterium. In order to obtain the active principle of the
bacterium, cells were grown in BDA culture medium for 96 h. The medium was then
centrifuged, filtered and then partitioned in chloroform to extract secondary fungicidal
metabolites. Through the preparative thin layer chromatography technique, it was possible to
obtain a mixture of the bioactive principles of B. amyloliquefaciens. Preliminary analyzes by
ESI-MSn of the mixture of the bioactive compounds showed at least five peaks whose three of
them can be a homologous series of heptapeptides.