The objectives of this study were i) to determine the effects of the interactions of water activity, temperature
and incubation time on the co-production of AFB1 and CPA by isolates of Aspergillus flavus with
different profile of mycotoxin production and ii) to identify the aW and temperature limiting conditions
for the production of both mycotoxins. Fungi used in this study were selected because they belonged to
different chemotypes: chemotype I (AFB1þ/CPAþ), III (AFB1þ/CPA) and IV (AFB1/CPAþ), respectively.
Two culture media were used; Czapek yeast agar (CYA) and corn extract agar (CEM), at different incubated
temperatures (10e40 C) and aW levels (0.80e0.98). AFB1 and CPA production were analyzed after
7, 14, 21 and 28 days of incubation. Significant differences were observed with respect to mycotoxin
production depending on the media evaluated. The AFB1 production occurred more favorably on CYA
while the highest CPA concentrations were recorded on CEM. Within the range of aW evaluated in this
study, 0.83 was the limiting level for both toxins production. The optimum conditions for AFB1 production
occurred at 0.96 aW and 30 C after 21 days of incubation, regardless of the media and isolate.
Although different amounts of toxins were produced in each medium, the limiting and optimum conditions
for their production were similar in both. No differences in the response of the three isolates to
the abiotic factors discussed were observed despite belonging to different chemotypes. The determination
of the thresholds of mycotoxins co-production, especially in the case of data obtained with the
corn extract medium can be useful to avoid the conditions conducive to co-occurrence of these mycotoxins
in corn.
The objectives of this study were i) to determine the effects of the interactions of water activity, temperature
and incubation time on the co-production of AFB1 and CPA by isolates of Aspergillus flavus with
different profile of mycotoxin production and ii) to identify the aW and temperature limiting conditions
for the production of both mycotoxins. Fungi used in this study were selected because they belonged to
different chemotypes: chemotype I (AFB1þ/CPAþ), III (AFB1þ/CPA) and IV (AFB1/CPAþ), respectively.
Two culture media were used; Czapek yeast agar (CYA) and corn extract agar (CEM), at different incubated
temperatures (10e40 C) and aW levels (0.80e0.98). AFB1 and CPA production were analyzed after
7, 14, 21 and 28 days of incubation. Significant differences were observed with respect to mycotoxin
production depending on the media evaluated. The AFB1 production occurred more favorably on CYA
while the highest CPA concentrations were recorded on CEM. Within the range of aW evaluated in this
study, 0.83 was the limiting level for both toxins production. The optimum conditions for AFB1 production
occurred at 0.96 aW and 30 C after 21 days of incubation, regardless of the media and isolate.
Although different amounts of toxins were produced in each medium, the limiting and optimum conditions
for their production were similar in both. No differences in the response of the three isolates to
the abiotic factors discussed were observed despite belonging to different chemotypes. The determination
of the thresholds of mycotoxins co-production, especially in the case of data obtained with the
corn extract medium can be useful to avoid the conditions conducive to co-occurrence of these mycotoxins
in corn.
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