Assessment of intraspecies variability in fungal growth initiation of Aspergillus flavus and aflatoxin B1 production under static and changing temperature levels using different initial conidial inoculum levels
MetadataShow full item record
Intraspecies variability in fungal growth and mycotoxin production has important implications for food safety. Using the Bioscreen C we have examined spectrophotometrically intraspecies variability of A. flavus using 10 isolates under different environments, including temperature shifts, in terms of
growth and aflatoxin B1 (AFB1) production. Five high and five low AFB1 producers were examined. The study was conducted at 5 isothermal conditions (from 15 to 37 °C) and 4 dynamic scenarios (between 15 and 30 °C). The experiments were carried out in a semisolid YES medium at 0.92 aw and two inoculum levels, 102 and 103 spores/mL. The Time to Detection (TTD) of growth initiation was determined and modelled as a function of temperature through a polynomial equation and the model was used to predict TTD under temperature upshifts conditions using a novel approach. The results obtained in this study have shown that a model can be developed to describe the effect of temperature upshifts on the TTD for all the studied isolates and inoculum levels. Isolate variability increased as the growth conditions became more stressful and with a lower inoculum level. Inoculum level affected the intraspecies variability but not the repeatability of the experiments. In dynamic conditions, isolate responses depended both on the temperature shift and, predominantly, the final temperature level. AFB1 production was highly variable among the isolates and greatly depended on temperature (optimum temperature at 30-35 °C) and inoculum levels, with often higher production with lower inoculum. This suggests that, from an ecological point of view, the potential isolate variability and interaction with dynamic conditions should be taken into account in developing strategies to control growth and predicting mycotoxin risks by mycotoxigenic fungi.
Is part ofInternational Journal of Food Microbiology, 2018, vol. 272, p. 1-11
European research projects
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Modelling the Probability of Growth and Aflatoxin B1 Production of Aspergillus Flavus under Changing Temperature Conditions in Pistachio Nuts Aldars García, Laila; Ramos Girona, Antonio J.; Sanchís Almenar, Vicente; Marín Sillué, Sònia (Elsevier, 2016)The aim of this work was to use probability models for the prediction of growth and aflatoxin production by Aspergillus flavus as a strategy to mitigate the aflatoxin presence in pistachio nuts during postharvest. Logistic ...
Single vs multiple-spore inoculum effect on growth kinetic parameters and modeled probabilities of growth and aflatoxin B1 production of Aspergillus flavus on pistachio extract agar Aldars García, Laila; Sanchís Almenar, Vicente; Ramos Girona, Antonio J.; Marín Sillué, Sònia (Elsevier, 2017)The objective of the present study was to assess the differences in modeled growth/AFB1 production probability and kinetic growth parameters for Aspergillus flavus inoculated as single spores or in a concentrated ...
An attempt to model the probability of growth and aflatoxin B1 production of Aspergillus flavus under non-isothermal conditions in pistachio nuts Aldars García, Laila; Ramos Girona, Antonio J.; Sanchís Almenar, Vicente; Marín Sillué, Sònia (Elsevier, 2015)Human exposure to aflatoxins in foods is of great concern. The aim of this work was to use predictive mycology as a strategy to mitigate the aflatoxin burden in pistachio nuts postharvest. The probability of growth and ...