Optimising the number of isolates to be used to estimate growth parameters of mycotoxigenic species
Data de publicació2012
Valls Marsal, Joan
MetadadesMostra el registre d'unitat complet
The aim of the present work was to mathematically assess the minimum number of isolates that would lead to equivalent growth parameters estimates to those obtained with a high number of strains. The datasets from two previous works on 30 Aspergillus carbonarius isolates and 62 Penicillium expansum isolates were used for this purpose. First, the datasets were used to produce a global estimation of growth parameters μ (growth rate, mm/d) and λ (time to visible growth, d) under the different experimental conditions, providing also a 95% confidence interval. Second, a computational algorithm was developed in order to obtain an estimation of the growth parameters that one would obtain using a lower number of isolates and/or replicates, using a bootstrap procedure with 5000 simulations. The result of this algorithm was the probability that the obtained estimation falls in the 95% confidence interval previously produced using all sample isolates. Third, the algorithm was intensively applied to obtain these probabilities for all possible combinations of isolates and replicates. Finally, these results were used to determine the minimum number of isolates and replicates needed to obtain a reasonable estimation, i.e. inside the confidence interval, with a probability of 0.8, 0.9 and 0.95. The results revealed that increasing the number of isolates may be more effective than increasing the number of replicates, in terms of increasing the probability. In particular, 12–17 isolates of A. carbonarius led to the same growth parameters as the total 30 (p = 0.05) or 9 isolates with p = 0.20; by contrast, 25–30 isolates of P. expansum led to the same growth parameters as the total 62 (p = 0.05) or 18–21 isolates with p = 0.20. As far as we know, this is the first study that provides a systematic evaluation of the number of isolates and replicates needed when designing an experiment involving mycotoxigenic moulds responses to environmental factors, and may serve to support decision making in this kind of studies or other similar ones.
És part deFood Microbiology, 2012, vol. 32, núm. 2, p. 235–242
Projectes de recerca europeus
Mostrant elements relacionats per títol, autor i matèria.
Growth parameters of Penicillium expansum calculated from mixed inocula as an alternative to account for intraspecies variability García, Daiana; Ramos Girona, Antonio J.; Sanchís Almenar, Vicente; Marín Sillué, Sònia (Elsevier, 2014)The aim of this work was to compare the radial growth rate (μ) and the lag time (λ) for growth of 25 isolates of Penicillium expansum at 1 and 20 ºC with those of the mixed inoculum of the 25 isolates. Moreover, the evolution ...
Is intraspecific variability of growth and mycotoxin production dependent on environmental conditions? A study with Aspergillus carbonarius isolates García, Daiana; Ramos Girona, Antonio J.; Sanchís Almenar, Vicente; Marín Sillué, Sònia (Elsevier, 2011)The aim of this study was to assess the impact of suboptimal environmental conditions on the intraspecific variability of A. carbonarius growth and OTA production using thirty isolates of A. carbonarius. Three aw/temperature ...
Mould growth and mycotoxin production as affected by Equisetum arvense and Stevia rebaudiana extracts García, Daiana; García Cela, Esther; Ramos Girona, Antonio J.; Sanchís Almenar, Vicente; Marín Sillué, Sònia (Elsevier, 2011)Cereals are very important for human and animal diet. However, agricultural products can be contaminated by moulds and their mycotoxins. On the other hand, natural plant products with antimicrobial properties could be a ...