Identification,Characterization, and Partial Purification of Glucoamylase from Aspergillus Niger (Syn A. Ficuum) NRRL 3135 |
| |
| Authors: | A S Vandersall R G Cameron C J Nairn III G Yelenosky Rudy J Wodzinski |
| |
| Institution: | 1. From Department of Molecular Biology and Microbiology , University of Central Florida , Orlando, Florida, 32816;2. Citrus and Subtropical Products Laboratory USDA-ARS , Winter Haven, Florida, 33883;3. Horticultural Research Laboratory USDA-ARS , Orlando, Florida, 32803 |
| |
| Abstract: | Abstract The crude extracellular extract of Aspergillus niger (syn A. ficuum) NRRL 3135 contains glucoamylase (exo-1,4-α-D-glucanohydrolase, EC 3.2.1.2). The enzyme, a glycoprotein, was purified 7-fold by ion-exchange chromatography, chromatofocusing, and conconavalin A affinity chromatography. The molecular weight of the enzyme was estimated to be 90 kDa by SDS-PAGE and gel permeation chromatography. The pI of the enzyme was 3.4. The temperature optimum of the enzyme was 60°C and the pH optimum was 5.0. The Vmax values for soluble starch, maltose, maltotriose, maltotetraose, maltopentaose, and isomaltose were 55.2, 11.7, 32.3, 47.8, 59.2, 12.5 nKat glucose/sec, respectively and the Km values for the same substrates were 0.09%, 0.67 mM, 0.76 mM, 0.76 mM, 0.68 mM, and 122.01 mM, respectively. |
| |
| Keywords: | |
|
|
