Table 2.

Effect of metal ions and other reagents on phytase activity from Aspergillus niger UFV-1

Metal ions and others reagents		Relative activity a (%)
Control		100
	5 mM	10 mM	20 mM
MgSO 4	95.3 ± 1.2	58.1 ± 0.9	28.9 ± 1.0
(CH 3 COO) 2 Mg	100.0 ± 0.6	26.6 ± 0.3	24.2 ± 1.5
C 4 H 6 CdO 4	95.5 ± 0.9	59.6 ± 2.5	27.3 ± 0.7
MnSO 4	74.9 ± 1.5	38.3 ± 1.6	21.4 ± 1.5
CuSO 4	81.2 ± 0.2	52.8 ± 1.8	18.9 ± 0.5
ZnSO 4	87.7 ± 2.7	52.2 ± 0.4	30.0 ± 1.1
ZnCl 2	81.0 ± 2.6	60.9 ± 1.1	38.0 ± 1.1
CaCl 2	96.3 ± 2.5	85.7 ± 0.5	64.6 ± 2.7
HgCl 2	75.6 ± 2.4	59.3 ± 1.7	49.8 ± 2.6
NaCl	76.1 ± 1.1	68.0 ± 1.8	51.4 ± 1.1
KCl	101.8 ± 1.4	98.0 ± 1.3	87.5 ± 1.5
Na 2 SO 4	76.8 ± 1.2	63.2 ± 0.9	38.4 ± 1.6
NaF	0	0	0
	1 mM	5 mM	20 mM
EDTA	218.7 ± 0.7	227.2 ± 2.1	234.4 ± 2.5
β-mercaptoethanol	94.9 ± 1.8	64.3 ± 1.6
DTT	97.5 ± 1.8	81.9 ± 2.0
	0.5 M	1 M	2 M
Urea	100.3 ± 2.7	75.8 ± 1.6	63.2 ± 1.8
Guanidine-HCl	42.0 ± 1.8	0	0
	0.1% (v/v)	0.5% (v/v)
SDS	0	0

^* Metal ions and other reagent concentrations were calculated as 5 mM, 10 mM and 20 mM of Mg ²⁺ , Cd ²⁺ (C ₄ H ₆ CdO ₄ = cadmium acetate), Mn ²⁺ , Cu ²⁺ , Zn ²⁺ , Ca ²⁺ , Hg ²⁺ , Na ⁺ , K ⁺ and F ⁻ ; 1 mM, 5 mM and 20 mM EDTA, β-mercaptoethanol and DTT; 0.5 M, 1 M and 2 M Urea, Guanidine-HCl and SDS.

^aPhytase activity was expressed as the mean ± SD (n = 3).