Purification and biophysical characterization of enzim xylanaza from aspergilus niger DSM 1957
2009
Do Thi Tuyen; Dam Thi Hong; Quyen Dinh Thi
The purification and characterization of xylanaza from Aspergillus niger DSM 1957 were investigated in this work. The optimal temperature and pH for the action of the enzyme were at 55oC and 5.0, respectively. This enzyme was stable at pH 6.0-8.0 and thermo-stable at 37-50oC. In general, metal ions inhibited the xylanaza at the concentration of 2 mM. Especially, metal ion Mg2+, Cu2+, Ca2+, K+ inhibited the xylanaza activity at the low- concentration (2 nM) and increased the xylanaza activity from 10% to 50% at high concentration (5-10 mM) after 5 hours incubation. The xylanaza was activated by Hg2+ up to 300% of activity, and was strongly inhibited by Zn2+. Detergent Tween 20 and SDS enhanced 15% to 20% xylanaza activity comparing with control at 0.2-1% concentration after 2 hours incubation. The detergent Trixton X- 100 inhibited 10% xylanaza activity comparing with control 0.2% - 1% concentration after 2 hours incubation. Organic solvents ethanol and isopropanol did not show a strong effect on the enzyme activity. The xylanaza was activated by methanol and acetone up to 300-500% of activity. N-butanol decreased the enzyme activity by 27% after 2 hours incubation.
Показать больше [+] Меньше [-]