Influence of a glyphosate-based herbicide on growth parameters and aflatoxin B1 production by Aspergillus section Flavi on maize grains Influencia de una formulación comercial a base de glifosato sobre los parámetros de crecimiento de Aspergillus sección Flavi y su producción de aflatoxina B1 en granos de maíz. Formulación comercial de glifosato sobre Aspergillus sección Flavi

MAGNOLI, KAREN; MAGNOLI, CARINA ELIZABETH; CARRANZA, CECILIA SOLEDAD; BARBERIS, CARLA LORENA; BENITO, NICOLÁS; ALUFFI, MELISA EGLÉ

REVISTA ARGENTINA DE MICROBIOLOGíA

ASOCIACION ARGENTINA MICROBIOLOGIA

Lugar: Buenos Aires ; Año: 2020

0325-7541

Glyphosate-based herbicides (GBH) are the main pesticides applied worldwide on maize production. Glyphosate-resistant weeds led to the repeated application of high doses of the pesticide. In addition to environmental conditions, the presence of GBH affects the development of Aspergillus species and aflatoxin B1 (AFB1) production under in vitro conditions. The aim of this work was to evaluate the influence of a commercial GBH on growth and AFB1 production by Aspergillus flavus and Aspergillus parasiticus strains under different water activity (aW) conditions. The following concentrations of active ingredient glyphosate were evaluated: 20, 50, 200 and 500 mM. The lag phase prior to growth and growth rate did not change at 20 and 50 mM (that is, at field recommended doses) at 0.98 and 0.95 aW; however, at increasing GBH concentrations, between 200 and 500 mM, the growth rate decreased at all aW conditions. In general, as the GBH concentration increased, AFB1 production decreased. However, a significant increase in toxin accumulation was found only at one of the aW conditions (0.95) at 21 days with 50 mM of GBH in A. flavus and 20 and 50 mM of GBH in A. parasiticus. These results show that, even though Aspergillus section Flavi growth did not increase, AFB1 production increased on maize grains at GBH concentrations similar to those of field recommended doses under favorable water availability and temperature conditions.