Author/Authors :
-، - نويسنده Department of Biochemistry and Biophysics, Faculty of Science, Tarbiat Modarres University, P.O. Box 14115-175 Tehran, I.R. IRAN Aminzadeh, Saeed , -، - نويسنده Department of Biochemistry and Biophysics, Faculty of Science, Tarbiat Modarres University,
P.O. Box 14115-175 Tehran, I.R. IRAN Naderi-Manesh, Hossein , -، - نويسنده Department of Biochemistry and Biophysics, Faculty of Science, Tarbiat Modarres University,
P.O. Box 14115-175 Tehran, I.R. IRAN Khajeh, Khosro , -، - نويسنده Department of Microbiology, Faculty of Scince, Alzahra University, P.O. Box 19935-644 Tehran, I.R. IRAN Soudi, Mohammad Reza
Abstract :
Thirty five fungal strains which isolated from vegetable wastes, were screened for the use of polygalacturonic acid as the sole carbon source. Twenty five isolates were positive for polygalacturonase activity in cup-plate assay, as evidenced by clear hydrolysation zones. The most productive strain was determined by measuring clear zones formed around colonies stained with ruthenium red. The highly pectinolytic fungal strain was tentatively identified as Tetra- occosporium sp. according to morphological characterization. The cultivation of the selected strain (Tetracoccosporium sp.) in liquid media resulted in high quantities of polygalacturonase enzyme. Maximum polygalacturonase activity was reached in 48 h of growth in the pectate medium. The collected polygalacturonase had optimum activity at pH 5.0 and maximal activity of the enzyme was determined at 35 °C. Mn2+, Ag3+and surface active detergents such as tween 20 and triton X-100 increased the polygalacturonase activity by 37 % and EDTA enhanced the activity up to 125 %.
