- Turkish Journal of Biology
- Vol: 36 Issue: 6
- Purification and properties of an endoglucanase from Aspergillus niger VTCC-F021
Purification and properties of an endoglucanase from Aspergillus niger VTCC-F021
Authors : Thi Hoa Pham, Dinh Thi Quyen, Ngoc Minh Nghiem
Pages : 694-701
View : 7 | Download : 3
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :An extracellular endoglucanase (EG) from Aspergillus niger VTCC-F021 was purified 2.09-fold to homogeneity with a yield of 18.4%. The enzyme had a molecular mass of 31 kDa and a specific activity of 14.122 U/mg protein. Optimum temperature was observed at 55 °C and optimum pH at 5. The enzyme was stable up to 50 °C and from pH 5 to 6 with residual activity >80% and 60%, respectively. The kinetic constants Km and Vmax determined for EG, with carboxyl methyl cellulose as a substrate, were 8.5815 mg CMC/mL and 20.121 U/mg protein, respectively. EDTA increased EG activity by 35% at 5 mM and decreased activity by 12% at 15 mM. The metal ions Cu2+ and Fe2+ activated EG activity 112%-152% at 5-15 mM. EG showed a high resistance to Tween 20 and Tween 80 at 0.5%-2.0% (w/v) and to ethanol and methanol at 10%-20% (v/v) with a residual activity of >80%. The biochemical properties of EG demonstrated that this enzyme was quite different from those of A. niger strains. These results suggested that EG from A. niger VTCC-F021 could be used to investigate the efficacy of feed enzymes.Keywords : Key words: Aspergillus niger VTCC-F021, carboxymethyl cellulose, endoglucanase, purification, characterization