Abhängigkeit der thermischen Abtötung von Mikroorganismen vom pH-Wert der Medien - I. Hefen und Schimmeluilze

Thermal inactivation of yeast cells and mould conidia is strongly pH-dependent at temperatures below 55 °C (131 °F). The influence of pH on thermal inactivation of microorganisms generally decreases with increasing temperatures and with heat-sensitive vegetative cells may be neglected above 65 °C (149 °F). At a given pH-value heat inactivation rates are dependent on the composition of the buffer systems used. Some organic acids like citric acid protect yeasts from thermal inactivation whereas others (like acetic acid) enhance heat inactivation. In the alkaline region yeast cells are rapidly killed by heat even at rather low temperatures. Maximal thermal resistance is shown by yeasts and mould conidia primarily in a weakly acidic medium.