Use of the Weibull model to describe inactivation of dry-harvested conidia of different Penicillium species by ethanol vapours

作者：Dao T; Dejardin J; Bensoussan M; Dantigny P^*

来源：Journal of Applied Microbiology, 2010, 109(2): 408-414.

DOI：10.1111/j.1365-2672.2010.04662.x

• conidia
• ethanol
• fungi
• inactivation
• Penicillium chrysogenum
• Penicillium digitatum
• Penicillium italicum
• predictive mycology

Aims:
This study aimed at modelling the effect of ethanol vapours, in the range 0 center dot 7-7 center dot 5 kPa, on the inactivation of dry-harvested conidia of Penicillium chrysogenum, Penicillium digitatum and Penicillium italicum.
Methods and Results:
Survival curves were modelled by a Weibull model: log (N/N(0)) = -1/2 center dot 303 (t/alpha)beta. The shape parameter beta was different from one in all cases, indicating that the classical first-order kinetics approach is the exception rather than the rule. Survival curves exhibited upward concavity (beta < 1) with the notable exception of P. chrysogenum at ethanol vapour pressures 0 center dot 7 and 1 center dot 5 kPa. The scale parameter alpha (h) varied greatly depending on the ethanol vapour pressure and on the species.
Conclusions:
For safety reasons, it is recommended not to exceed an ethanol vapour pressure of 3 center dot 3 kPa. At 2 center dot 8 kPa, more than 4 log(10) reductions in viable conidia were achieved for all the species after 24-h exposure.
Significance and Impact of the Study:
Ethanol has GRAS status in the USA and represents an interesting alternative to fungicides. The effectiveness of ethanol vapours to inactivate dry-harvested conidia of some Penicillium was demonstrated in this study.

• 出版日期2010-8