Prediction of conidial germination of Penicillium chrysogenum as influenced by temperature, water activity and pH.
OBJECTIVE
Conidial germination of Penicillium chrysogenum was carried out under operating conditions compatible with a pastries manufacturing process.


RESULTS
A range, limited by two experimental values, was defined for each environmental factor tested: temperature (15 or 25 degrees C), water activity (0.75 or 0.85) and pH (3.5 or 5.5). A closed device was made, which maintained an equilibrium between water activity of the culture medium and atmospheric relative humidity during 25 days, to follow spore germination. The combined effects of temperature, water activity and pH on spore germination were studied by applying factorial design methodology.


CONCLUSIONS
Higher rates of spore germination were associated with a high level of water activity. The incubation temperature also had a positive effect. A significant positive interaction between water activity and temperature was observed. Under these specific experimental conditions, pH did not have a significant effect on conidial germination.


CONCLUSIONS
A model describing the behaviour of fungal conidia is proposed.
Université de Bourgogne, ENS.BANA, Laboratoire de Microbiologie - UMR INRA, Dijon, France.
M
M
Sautour
A
A
Rouget
P
P
Dantigny
C
C
Divies
M
M
Bensoussan
D006863:Hydrogen-Ion Concentration; D010408:Penicillium chrysogenum / Q000254:growth & development / Q000502:physiology*; D013172:Spores, Fungal; D013696:Temperature; D014867:Water / Q000502:physiology*
D014867:Water