Open AccessDiscrimination of Aspergillus niger and other Aspergillus species belonging to section Nigri by PCR assays
Author(s) -
GonzálezSalgado Amaia,
Patiño Belén,
Vázquez Covadonga,
GonzálezJaén Ma Teresa
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.03.023
Subject(s) - aspergillus niger , aspergillus , biology , internal transcribed spacer , ochratoxin a , mycotoxin , polymerase chain reaction , ochratoxin , botany , genetics , phylogenetic tree , gene , microbiology and biotechnology
Aspergillus species included in section Nigri are common in plant products and processed food, such as grapes, cereals, coffee and derivatives, particularly in warm and tropical climates. Two of these species, A. carbonarius and A. niger , are known to produce ochratoxin A (OTA), a potent nephrotoxin and carcinogenic to human (group 2B). Recognition of the several species of this section is difficult and requires considerable expertise using conventional methods based on morphological features. In this work we describe rapid, sensitive and robust assays based on the PCR technique to discriminate the main species included in section Nigri : A. japonicus , A. heteromorphus , A. ellipticus and the two morphologically indistinguishable species of the A. niger aggregate: A. niger and A. tubingensis. The species‐specific primers have been designed on the basis of ITS (internal transcribed spacers of rDNA units) sequence comparisons obtained from several Aspergillus strains and have been tested in a number of strains from different origins and hosts. These PCR assays, based on multi‐copy sequences, are highly sensitive and specific and represent a good tool for an early detection of OTA‐producing Aspergillus species in order to prevent OTA from entering the food chain.