The optimum temperature of protease activity was identifiedby carrying out activity tests at pH05.0, S0= 100 mg/L and vary-ing T from 30 to 75.C. To minimize the influence of activity loss due to irreversible denaturation of protease, only the initial values of enzyme activity (v0) were taken into consideration. The protease proved to be active over a relatively wide T range (30–65◦C) with anoptimal value at 55◦C. The semi-log plot of lnv0vs 1/T showed a lin-ear increase below 55◦C, whereas an opposite trend was observed over this threshold value (Fig. 3). Such an optimum temperature isconsistent with that reported by other researchers for extracellular proteases of other aspergilli, namely A. fumigatus