title: [Extrinsic and intrinsic factors associated with mycotoxigenic fungi populations of maize grains (Zea mays L.) stored in silobags in Argentina].
abstract: In order to determine the behavior of mycotoxin-producing fungal populations linked with silobags stored corn grains with a moisture content greater at the recommended as safe, 270 samples taken in three times (beginning, 90 days, final) over a five month period of storage were evaluated. The fungal biota was quantified and identified and the contamination with fumonisin and aflatoxin was determined. Extrinsic factors (environment), intrinsic factors (grains) and technological factors (location of the grains in the profile of silobag) were taken into account to evaluate the presence and quantity of total and mycotoxigenic fungal populations. The pH of grains and O2 levels were significantly reduced after five months, while CO2 concentration increased in the same period. The total counts of mycobiota were significantly higher in grains located in the top layer of silobag. Mycotoxigenic species of Fusarium, Aspergillus, Penicillium and Eurotium were identified. The frequency of isolation of Fusarium verticillioides decreased at the end of storage and Aspergillus flavus was isolated only at the beginning of storage. The counts of the Penicillium spp. and Eurotium spp. were increased at the end of storage. Fumonisin contamination was found in all the samples (100%) with maximum levels of 5.707mg/kg whereas aflatoxin contaminated only 40% with maximum levels of 0.0008mg/kg. The environmental and substrate conditions generated during the storage limited the development of mycotoxigenic fungi and mycotoxin production.
authors.affiliation: Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Balcarce, Buenos Aires, Argentina. Electronic address: claudia_castellari@yahoo.com.ar.
authors.forename: Claudia C
authors.initials: CC
authors.lastname: Castellari
authors.affiliation: Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Balcarce, Buenos Aires, Argentina.
authors.forename: María G
authors.initials: MG
authors.lastname: Cendoya
authors.affiliation: Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Balcarce, Buenos Aires, Argentina.
authors.forename: Facundo J
authors.initials: FJ
authors.lastname: Marcos Valle
authors.affiliation: Instituto de Microbiología y Zoología Agrícola, Centro Nacional de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (INTA), Castelar, Buenos Aires, Argentina.
authors.forename: Viviana
authors.initials: V
authors.lastname: Barrera
authors.affiliation: Fundación de Investigaciones Científicas Teresa Benedicta de la Cruz, Luján, Buenos Aires, Argentina.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Pacin
mesh_terms: D001118:Argentina; D000069601:Crop Protection; D005658:Fungi / Q000302:isolation & purification* / Q000378:metabolism*; D009183:Mycotoxins / Q000096:biosynthesis*; D003313:Zea mays / Q000382:microbiology*
chemical_list: D009183:Mycotoxins
keywords: Atmósfera autorregulada; Fumonisin; Fumonisinas; Maize (Zea mays L.); Maíz (Zea mays L.); Micobiota toxigénica; Self-regulated atmospheres; Silo bolsa; Silobag; Toxigenic mycobiota; pH de granos; pH grains