Research Information System
FOOD CHEMISTRY, vol.111, no.4, pp.824-829, 2008 (SCI-Expanded)
Crude exo-polygalacturonase enzyme (produced by Aspergillus sojae), significant for industrial processes, was characterized with respect to its biochemical and thermal properties. The optimum pH and temperature for maximum crude exo-polygalacturonase activity were pH 5 and 55 degrees C, respectively. It retained 60-70% of its activity over a broad pH range and 80% of its initial activity at 65 degrees C for 1 h. The thermal stability study indicated an inactivation energy of E-d = 152 kJ mol(-1). The half lives at 75 and 85 degrees C were estimated as 3.6 and 1.02 h, respectively. Thermodynamic parameters, Delta H-*, Delta S-* and Delta G(*), were determined as a function of temperature, The kinetic constants K-m, and V-max, using polygalacturonic acid as substrate, were determined as 0.424 g l(-1) and 80 mu mol min(-1), respectively. SDS-PAGE profiling revealed three major bands with molecular weights of 36, 53 and 68 kDa. This enzyme can be considered as a potential candidate in various applications of waste treatment, in food, paper and textile industries. (c) 2008 Elsevier Ltd. All rights reserved.