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Biodiversity of Aspergillus species in some important agricultural products.

Perrone G, Susca A, Cozzi G, Ehrlich K, Varga J, Frisvad JC, Meijer M, Noonim P, Mahakarnchanakul W, Samson RA - Stud. Mycol. (2007)

Bottom Line: Within A. flavus and other Aspergillus species capable of aflatoxin production, considerable diversity is found.We summarise the main recent achievements in the diversity of the aflatoxin gene cluster in A. flavus populations, A. parasiticus and the non-toxigenic A. oryzae.Studies are needed in order to characterise the aflatoxin biosynthetic genes in the new related taxa A. minisclerotigenes and A. arachidicola.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sciences of Food Production, CNR, Via Amendola, 122/O 70126 Bari, Italy.

ABSTRACT
The genus Aspergillus is one of the most important filamentous fungal genera. Aspergillus species are used in the fermentation industry, but they are also responsible of various plant and food secondary rot, with the consequence of possible accumulation of mycotoxins. The aflatoxin producing A. flavus and A. parasiticus, and ochratoxinogenic A. niger, A. ochraceus and A. carbonarius species are frequently encountered in agricultural products. Studies on the biodiversity of toxigenic Aspergillus species is useful to clarify molecular, ecological and biochemical characteristics of the different species in relation to their different adaptation to environmental and geographical conditions, and to their potential toxigenicity. Here we analyzed the biodiversity of ochratoxin producing species occurring on two important crops: grapes and coffee, and the genetic diversity of A. flavus populations occurring in agricultural fields. Altogether nine different black Aspergillus species can be found on grapes which are often difficult to identify with classical methods. The polyphasic approach used in our studies led to the identification of three new species occurring on grapes: A. brasiliensis, A. ibericus, and A. uvarum. Similar studies on the Aspergillus species occurring on coffee beans have evidenced in the last five years that A. carbonarius is an important source of ochratoxin A in coffee. Four new species within the black aspergilli were also identified in coffee beans: A. sclerotioniger, A. lacticoffeatus, A. sclerotiicarbonarius, and A. aculeatinus. The genetic diversity within A. flavus populations has been widely studied in relation to their potential aflatoxigenicity and morphological variants L- and S-strains. Within A. flavus and other Aspergillus species capable of aflatoxin production, considerable diversity is found. We summarise the main recent achievements in the diversity of the aflatoxin gene cluster in A. flavus populations, A. parasiticus and the non-toxigenic A. oryzae. Studies are needed in order to characterise the aflatoxin biosynthetic genes in the new related taxa A. minisclerotigenes and A. arachidicola.

No MeSH data available.


Related in: MedlinePlus

Causes of A. flavus diversity.
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fig7: Causes of A. flavus diversity.

Mentions: Aspergillus flavus is the most common species associated with aflatoxin contamination of agricultural crops (Cotty et al. 1994, Cotty 1997) (Fig. 7). A. flavus populations are highly diverse and their stability in the soil and on the plant is not well understood. An atoxigenic relative of A. flavus, A. oryzae, is widely used in Asian fermentation processes. It is now increasingly clear that A. oryzae is not a separate species, but actually is only one many examples of atoxigenic variants of A. flavus (Geiser et al. 2000). As much as 40 % of the soil isolates of A. flavus are incapable of producing aflatoxins (Cotty et al. 1994). Addition of atoxigenic strains of A. flavus to the soil of susceptible crops to dilute out toxin-producing strains is being used to remediate aflatoxin contamination of cotton and peanuts (Cotty and Bayman 1993, Horn et al. 2000, Horn and Dorner 2002).


Biodiversity of Aspergillus species in some important agricultural products.

Perrone G, Susca A, Cozzi G, Ehrlich K, Varga J, Frisvad JC, Meijer M, Noonim P, Mahakarnchanakul W, Samson RA - Stud. Mycol. (2007)

Causes of A. flavus diversity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2275197&req=5

fig7: Causes of A. flavus diversity.
Mentions: Aspergillus flavus is the most common species associated with aflatoxin contamination of agricultural crops (Cotty et al. 1994, Cotty 1997) (Fig. 7). A. flavus populations are highly diverse and their stability in the soil and on the plant is not well understood. An atoxigenic relative of A. flavus, A. oryzae, is widely used in Asian fermentation processes. It is now increasingly clear that A. oryzae is not a separate species, but actually is only one many examples of atoxigenic variants of A. flavus (Geiser et al. 2000). As much as 40 % of the soil isolates of A. flavus are incapable of producing aflatoxins (Cotty et al. 1994). Addition of atoxigenic strains of A. flavus to the soil of susceptible crops to dilute out toxin-producing strains is being used to remediate aflatoxin contamination of cotton and peanuts (Cotty and Bayman 1993, Horn et al. 2000, Horn and Dorner 2002).

Bottom Line: Within A. flavus and other Aspergillus species capable of aflatoxin production, considerable diversity is found.We summarise the main recent achievements in the diversity of the aflatoxin gene cluster in A. flavus populations, A. parasiticus and the non-toxigenic A. oryzae.Studies are needed in order to characterise the aflatoxin biosynthetic genes in the new related taxa A. minisclerotigenes and A. arachidicola.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sciences of Food Production, CNR, Via Amendola, 122/O 70126 Bari, Italy.

ABSTRACT
The genus Aspergillus is one of the most important filamentous fungal genera. Aspergillus species are used in the fermentation industry, but they are also responsible of various plant and food secondary rot, with the consequence of possible accumulation of mycotoxins. The aflatoxin producing A. flavus and A. parasiticus, and ochratoxinogenic A. niger, A. ochraceus and A. carbonarius species are frequently encountered in agricultural products. Studies on the biodiversity of toxigenic Aspergillus species is useful to clarify molecular, ecological and biochemical characteristics of the different species in relation to their different adaptation to environmental and geographical conditions, and to their potential toxigenicity. Here we analyzed the biodiversity of ochratoxin producing species occurring on two important crops: grapes and coffee, and the genetic diversity of A. flavus populations occurring in agricultural fields. Altogether nine different black Aspergillus species can be found on grapes which are often difficult to identify with classical methods. The polyphasic approach used in our studies led to the identification of three new species occurring on grapes: A. brasiliensis, A. ibericus, and A. uvarum. Similar studies on the Aspergillus species occurring on coffee beans have evidenced in the last five years that A. carbonarius is an important source of ochratoxin A in coffee. Four new species within the black aspergilli were also identified in coffee beans: A. sclerotioniger, A. lacticoffeatus, A. sclerotiicarbonarius, and A. aculeatinus. The genetic diversity within A. flavus populations has been widely studied in relation to their potential aflatoxigenicity and morphological variants L- and S-strains. Within A. flavus and other Aspergillus species capable of aflatoxin production, considerable diversity is found. We summarise the main recent achievements in the diversity of the aflatoxin gene cluster in A. flavus populations, A. parasiticus and the non-toxigenic A. oryzae. Studies are needed in order to characterise the aflatoxin biosynthetic genes in the new related taxa A. minisclerotigenes and A. arachidicola.

No MeSH data available.


Related in: MedlinePlus