Biblioteca Digital do Instituto Politécnico de Bragança   Instituto Politécnico de Bragança

Biblioteca Digital do IPB >
Escola Superior Agrária >
Biologia e Biotecnologia >
BB - Artigos em Revistas Indexados ao ISI/Scopus >

Please use this identifier to cite or link to this item:

Título: A polyphasic approach to the identification of aflatoxigenic and non-aflatoxigenic strains of Aspergillus section flavi isolated from portuguese almonds
Autor: Rodrigues, Paula
Venâncio, Armando
Kozakiewicz, Zofia
Lima, Nelson
Palavras-chave: Aspergillus
Section flavi
Cyclopiazonic acid
Issue Date: 2009
Editora: Elsevier
Citação: International Journal of Food Microbiology. ISSN 0168-1605. 129:2 (2009) p. 187-193.
Resumo: A polyphasic approach consisting of morphological, chemical and molecular characterization was applied to 31 isolates of Aspergillus Section Flavi originating from Portuguese almonds, with the aim of characterizing and identifying aflatoxigenic and non-aflatoxigenic strains. On the basis of morphological characters (mainly colony color on Czapek-Dox agar and conidia morphology), we found two distinct groups among the population under study: 18 isolates (58%) had dark-green colonies and rough conidia, and were classified as A. parasiticus; the remaining 13 isolates (42%) had yellow-green colonies and smooth to finely rough globose conidia, and were classified as A. flavus. Chemical characterization involved the screening of the isolates for aflatoxins B (AFB) and G (AFG), and also for cyclopiazonic acid (CPA), by HPLC with fluorescence and UV detection, respectively. All A. parasiticus isolates were strong AFB and AFG producers, but no CPA production was detected, showing a consistent mycotoxigenic pattern. The A. flavus isolates showed to be more diversified, with 77% being atoxigenic, whereas 15% produced CPA and low levels of AFB and 8% produced the 3 groups of mycotoxins. Aflatoxin production was also screened on Coconut Agar Medium (CAM), and the results were consistent with the HPLC analysis. Sclerotia production showed no correlation to aflatoxigenicity. Molecularly, two genes of the aflatoxin biosynthetic pathway, aflD (= nor1) and aflQ (= ord1= ordA) were tested for presence and expression (by PCR and RT-PCR, respectively). The presence of both genes did not correlate with aflatoxigenicity. aflD expression was not considered a good marker for differentiating aflatoxigenic from non-aflatoxigenic isolates, but aflQ showed a good correlation between expression and aflatoxin-production ability.
ISSN: 0168-1605
Versão do Editor:
Appears in Collections:BB - Artigos em Revistas Indexados ao ISI/Scopus

Files in This Item:

File Description SizeFormat
Artigo_Rev_Intern_Index[2].pdf357,65 kBAdobe PDFView/Open
Restrict Access. You can request a copy!
1542 resumo.pdf84,17 kBAdobe PDFView/Open

Please give feedback about this item
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


© Instituto Politécnico de Bragança - Biblioteca Digital - Feedback - Statistics
Promotores do RCAAP   Financiadores do RCAAP

Fundação para a Ciência e a Tecnologia Universidade do Minho   Governo Português Ministério da Educação e Ciência PO Sociedade do Conhecimento (POSC) Portal oficial da União Europeia