Effects of the volatile organic compounds produced by Enterococcus spp. strains isolated from maize grain silos on Fusarium verticillioides growth and fumonisin B1 production.

GERGOLET DIAZ D.; PIZZOLITTO R.; USSEGLIO, V. L.; VAZQUEZ C. ; ZUNINO M.P; DAMBOLENA J.S; ZYGADLO J.A; MERLO C.

JOURNAL OF STORED PRODUCTS RESEARCH

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2021 vol. 93

0022-474X

Fusarium verticillioides is a phytopathogenic fungus that can contaminate maize grain silos and result in importantlosses in the post-harvest product. The objective of this work was to investigate the effects of volatile organiccompounds produced by four lactic acid bacterial strains isolated from maize grain silos on F. verticillioidesM3125 growth and fumonisin B1 (FB1) production. The bacterial isolates 55 and 49 were identified as Enterococcusfaecium and M4A and M4G as Enterococcus casseliflavus. The fungal growth was inhibited by 33.33% by thevolatiles released by the M4A strain and by approximately 10% by the volatiles emitted by the 55 and 49 strains.The volatiles produced by the M4A strain also significantly reduced (88.75%) FB1 biosynthesis. The gas chromatography?mass spectrometer analysis identified 21 volatile organic compounds, with diacetyl, acetic acid andacetoin being the main volatiles emitted by the four bacterial strains. Acetoin was the volatile produced in thehighest proportion by the four strains, with M4A generating the highest proportion of diacetyl (35.11%). Diacetyland acetic acid completely inhibited fungal growth at concentrations of 0.3 and 1 mM, respectively, whileacetoin promoted fungal growth. Only acetoin significantly reduced FB1 production. These results showed thatdiacetyl was the main compound involved in fungal inhibition, while the effect on FB1 production could havebeen due to the combination of the volatile organic compounds produced by the M4A strain. In conclusion, thevolatiles emitted by the E. casseliflavus M4A strain could be a promising tool for the biocontrol of F. verticillioidesin storage maize grain silos.