Temperature influence on Penicillium citrinum thom growth and citrinin accumulation kinetics.

To study the temperature influence on both Penicillium citrinum growth and citrinin accumulation, a 20, 25 and 30 degrees C. Radial and 30 degrees C. Radial growth rate and lag phase were determined from the increase in colony diameter with time. The optimal temperature for P. citrinum growth was 30 degrees C. Citrinin extracted from the agar medium was determined by thin layer chromatography. Citrinin accumulation kinetics were analyzed by fitting the data to curves generated by using a logistic function. The parameters obtained from this equation demonstrated, for all temperatures studied, that the maximum citrinin accumulation by P. citrinum on Czapek agar with maize extract was at about 30 degrees C. At 37 degrees C a rapid decrease in the citrinin concentration was observed after a maximal value was reached.