|
Metal ions
|
Relative activity (%)
|
|---|
|
Xyl1
|
Xyl2
|
Xyl3
|
|---|
|
Control
|
100.0 ± 0.9
|
100.0 ± 1.2
|
100.0 ± 0.5
|
|
Ca2+
|
94.3 ± 1.1
|
80.4 ± 4.8
|
89.2 ± 0.4
|
|
K+
|
109.4 ± 0.6
|
105.0 ± 1.1
|
105.3 ± 0.5
|
|
Ag+
|
17.5 ± 0.4
|
8.7 ± 1.0
|
5.0 ± 0.2
|
|
Pb2+
|
78.9 ± 0.3
|
43.8 ± 0.3
|
53.5 ± 0.7
|
|
Ni2+
|
100.1 ± 0.1
|
81.6 ± 0.3
|
98.2 ± 3.0
|
|
Mg2+
|
97.2 ± 0.7
|
84.0 ± 0.1
|
93.4 ± 1.1
|
|
Cu2+
|
54.7 ± 0.7
|
11.4 ± 0.4
|
14.2 ± 0.6
|
|
Co2+
|
103.6 ± 0.4
|
82.7 ± 0.6
|
86.4 ± 0.2
|
|
Na+
|
108.9 ± 0.8
|
102.6 ± 0.3
|
102.8 ± 1.1
|
|
Fe3+
|
95.7 ± 0.3
|
42.2 ± 0.3
|
67.2 ± 0.4
|
|
Zn2+
|
109.8 ± 0.2
|
81.7 ± 0.7
|
96.6 ± 0.2
|
|
Al3+
|
108.3 ± 0.2
|
61.9 ± 2.1
|
97.4 ± 0.1
|
- Experiments were carried out in the presence of 10 mM metal ions at optimal conditions (35 °C and pH 6.0 for Xyl1; 50 °C and pH 5.0 for Xyl2; 55 °C and pH 6.0 for Xyl3), using 1.0% beechwood xylan as substrate. The relative enzyme activity was calculated using the activity of the enzyme without any added metal ions as 100%
- The experiments were performed in duplicate, and the data are presented as the means ± standard deviations
