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Enzyme Research
Volume 2012 (2012), Article ID 196853, 6 pages
Research Article

A Thermostable Crude Endoglucanase Produced by Aspergillus fumigatus in a Novel Solid State Fermentation Process Using Isolated Free Water

Food and Biotechnology Research Centre, PCSIR Labs Complex, Ferozepur Road, Lahore 54600, Pakistan

Received 4 April 2012; Revised 12 May 2012; Accepted 17 May 2012

Academic Editor: Jose M. Guisan

Copyright © 2012 Abdul A. N. Saqib et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Aspergillus fumigatus 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 A. fumigatus 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 (T1/2) of the enzyme were 6930, 866, and 36 min at 60°C, 70°C, and 80°C, respectively. Enthalpies of activation of denaturation (ΔHD*) were 254.04, 253.96, and 253.88 K J mole−1, at 60°C, 70°C and 80°C, respectively, whereas entropies of activation of denaturation (ΔSD*) and free energy changes of activation of denaturation (ΔGD*) were 406.45, 401.01, and 406.07 J mole−1 K−1 and 118.69, 116.41, and 110.53 K J mole−1 at 60°C, 70°C and 80°C, respectively.