title: Effect of climatic conditions on natural mycoflora and fumonisins in freshly harvested corn of the State of Paraná, Brazil.
abstract: Natural mycoflora associated with fumonisins were analyzed in 150 samples of freshly harvested corn from Central-Southern, Central-Western and Northern regions of the State of Paraná, Brazil and correlated to climatic conditions. The corn samples were frequently contaminated with Fusarium sp. (98.7 to 100%) and Penicillium sp. (93 to 100%), when compared to Aspergillus sp. (not detected to 27.7%). The highest contamination with potentially mycotoxigenic fungi occurred in corn harvested in the Central-Western region, where total mould and yeast counts ranged from 5.5 x 10(3) to 5.2 x 10(6) CFU/g, with 98.7% contaminated by Fusarium sp. and 93% by Penicillium sp. In this region F. moniliforme (F. verticillioides) was the predominant Fusarium sp., and was isolated in 85.9% of the samples. Aspergillus sp. was isolated from 27.7% samples. FB1 was detected in 100% of the samples (mean of 2.39 micrograms/g) and FB2 in 97.7% (mean of 1.09 micrograms/g). Fumonisins were also detected in all samples from Northern region, with mean of 4.56 micrograms/g (FB1) and 2.20 micrograms/g (FB2). Considering 1.0 microgram/g as the threshold, 72% of the corn samples from the Central-West and 92% from the North were contaminated with concentrations above this value, in contrast to a 18.5% contamination rate from Central-Southern samples. Between corn planting to harvesting season, the average maximum temperature and relative humidity were 26 degrees C and 77.1% (Central-Southern), 27 degrees C and 69% (Northern) and 29.9 degrees C and 89.1% (Central-Western). Therefore, the higher fumonisins contamination of corn from Northern region when compared to the Central-South were due to the differences in rainfall levels (92.8 mm in Central-Southern, 202 mm in Northern) during the month preceding harvest.
authors.affiliation: Department of Biochemistry, State University of Londrina, Paraná, Brazil. eysono@uel.br
authors.forename: E Y
authors.initials: EY
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Sugiura
authors.forename: M
authors.initials: M
authors.lastname: Homechin
authors.forename: M
authors.initials: M
authors.lastname: Kamogae
authors.forename: E
authors.initials: E
authors.lastname: Vizzoni
authors.forename: Y
authors.initials: Y
authors.lastname: Ueno
authors.forename: E Y
authors.initials: EY
authors.lastname: Hirooka
mesh_terms: D001230:Aspergillus / Q000302:isolation & purification; D001938:Brazil; D002980:Climate; D005670:Fusarium / Q000302:isolation & purification; D003904:Mitosporic Fungi / Q000302:isolation & purification*; D009183:Mycotoxins / Q000032:analysis*; D010407:Penicillium / Q000302:isolation & purification; D003313:Zea mays / Q000382:microbiology*
chemical_list: D009183:Mycotoxins