Mycoflora and Fumonisin Contamination in Brazilian Corn from Sowing to Harvest

Abstract

The present study aimed to analyze the mycoflora and potential mycotoxin contamination of soil and corn samples collected at different plant maturity stages in Capão Bonito and Ribeirão Preto, two regions of the State of São Paulo, Brazil. In addition, the data obtained were correlated with the occurrence of wind-dispersed fungi and the predominant climatic conditions of the two regions studied. Corn mycoflora profiles showed that Fusarium verticillioides prevailed in 35% of the samples from Capão Bonito and in 49% of the samples from Ribeirão Preto. Examination of wind-dispersed fungi also revealed a high incidence of F. verticillioides. Soil mycoflora analyses showed that Penicilliumwas the most prevalent genus, although F. verticillioides was present in 55.5% of Capão Bonito's samples and in 26.7% of Ribeirão Preto's samples. With respect to water activity, the corn kernels most contaminated with F. verticillioides had water activity levels of 0.70-0.80. HPLC analysis of fumonisins revealed that 88.5% of Capão Bonito's kernels were contaminated with fumonisin B(1) (FB(1)) (0.09-10.87 microg/g) and 53.8% with fumonisin B(2) (FB(2)) (0.05-0.52 microg/g); Ribeirão Preto's kernels presented contamination levels of 93.5% for FB(1) (0.11-17.69 microg/g) and 61.3% for FB(2) (0.05-5.24 microg/g). No aflatoxins were detected by thin-layer chromatography in corn grains of either region. The concomitant occurrence of F. verticillioides and fumonisins in most of the field corn assayed demonstrates the importance of an effective control of cultivation throughout the plant maturity stages.

Fungal Infection and Mycotoxins Contamination in Organic and Conventional Maize

“…In Brazil was reported a higher incidence of F. verticillioides, Penicillium spp. and A. flavus in maize samples at different stages of maturity (Almeida et al, 2002). These results were also reported by Covarelli et al (2011), in corn grains from different locations in Umbria (central Italy).…”

“…Almeida et al (2002) Samples of maize-based foods (121), which were collected in the city of Maringá, PR, Brazil, showed AFB1 contamination in 3 samples, 2 samples with AFB2, 1 sample with OTA and 1 sample with ZEA. Krout-Greenberg et al (2013) evaluated 50 random samples of whole maize and aflatoxins were detected in 14 samples, where only one sample contained a high concentration.…”

Estudo sobre a ocorrência de fungos e aflatoxina B1 na dieta de bovinos leiteiros em São Paulo

“…foram isoladas de culturas de cereais no campo, entretanto as espécies do fungo Fusarium spp são as mais encontradas no Brasil quando analisados os isolamentos em grãos de cereais destinados à alimentação animal (Almeida et al 2002). Considerados como fungos de campo, os fungos desse gênero invadem os tecidos da planta durante o desenvolvimento, quando os teores de umidade no grão são mais elevados, ao contrário do gênero Aspergillus spp., mais tolerantes a conteúdos de umidade mais baixos e considerados fungos de armazenamento.…”

Sistemas de rotação de culturas e infecção de grãos de milho por Fusarium verticillioides em regiões produtoras no estado de São Paulo.

“…A cultura de milho pode ser afetada por diversos agentes, destacando-se os vírus, bactérias e fungos (CASA; REIS, 2003;PEREIRA, 1997 (ALMEIDA et al, 2000;ALMEIDA et al, 2002;ALMEIDA et al, 2005;CORRÊA et al, 1997;HIROOKA et al, 1996;ONO et al, 1999;ORSI et al, 2000;POZZI et al, 1995;ROCHA et al, 2009). respectivamente.…”

“…No Brasil, estudos apontam F. verticillioides, considerado fungo endofítico, como o de maior frequência em grãos de milho recém-colhido e armazenado (ALMEIDA et al, 2000;ALMEIDA et al, 2002;ALMEIDA et al, 2005;ORSI et al, 2000;ROCHA et al, 2009), porém, nosso trabalho revelou frequência de isolamento deste fungo inferior aos trabalhos citados anteriormente.…”