초록
<P><I>Aspergillus fumigatus</I> was grown on chopped wheat straw in a solid state fermentation (SSF) process carried out in constant presence of isolated free water inside the fermentation chamber. The system allowed maintaining a constant vapor pressure inside the fermentor throughout the fermentation process. Crude endoglucanase produced by <I>A. fumigatus</I> under such conditions was more thermostable than previously reported enzymes of the same fungal strain which were produced under different conditions and was also more thermostable than a number of other previously reported endoglucanases as well. Various thermostability parameters were calculated for the crude endoglucanase. Half lives (<I>T</I><SUB>1/2</SUB>) of the enzyme were 6930, 866, and 36 min at 60°C, 70°C, and 80°C, respectively. Enthalpies of activation of denaturation (Δ<I>H</I><SUB><I>D</I></SUB>*) were 254.04, 253.96, and 253.88 K J mole<SUP>−1</SUP>, at 60°C, 70°C and 80°C, respectively, whereas entropies of activation of denaturation (Δ<I>S</I><SUB><I>D</I></SUB>*) and free energy changes of activation of denaturation (Δ<I>G</I><SUB><I>D</I></SUB>*) were 406.45, 401.01, and 406.07 J mole<SUP>−1</SUP> K<SUP>−1</SUP> and 118.69, 116.41, and 110.53 K J mole<SUP>−1</SUP> at 60°C, 70°C and 80°C, respectively.</P>