Table 3.

Effect of metals and chemical reagents on the activity of A. placomyces laccase.

Metal ion	Relative activity (% of control)
	1.25 mM	2.5 mM	5.0 mM
K+	93	92	91
Ca2+	105	108	106
Cu2+	58	65	71
Hg2+	45	34	25
Mg2+	105	99	99
Mn2+	105	108	109
Pb2+	52	55	56
Zn2+	96	91	86
Al3+	157	114	106
Fe3+	68	60	47
EDTA	61	47	32

Laccase activity in the absence of chemical reagents was regarded as 100%.