Modelling the effect of temperature, water activity and solute on the in vitro growth of the biocontrol yeast Pichia anomala strain K

摘要

The objective of this work was to evaluate and model the combined effect of temperature (5-25 degrees C) and water activity (a(w), 0.890-0.980) on Pichia anomala strain K growth and lag phase. Variance analysis showed a highly significant effect ofa(w), solute and temperature on strain K growth. The decrease of a(w) and temperature significantly reduced and delayed growth, the effect being more drastic with NaCl compared to the other solutes. Response surface models relating the natural logarithmof growth with a(w) and temperature were developed for each solute. Optimum growth was obtained at a(w) values ranging from 0.980 to 0.995 at 25 degrees C. For all models, there was good agreement between observed and predicted values. However, only models based on sorbitol and glucose accurately described experimental growth data. Implementation of the present results in combination with our previous findings on four main post-harvest pathogens should result in a more effective biocontrol strategy to limit fruit losses