Production and Characterization of Alkaline Protease from a High Yielding and Moderately Halophilic Strain of SD11 Marine Bacteria

Table 3

Influences of the activity of the crude protease by various metal ions and enzyme inhibitors.

Chemicals	None	PMSF	EDTA	Ca^2+	Mn^2+	Zn^2+	Cu^2+	Na^+	K^+
Concentration (mM)	—	5	5	5	5	5	5	5	5
Activity (%)	100	0	107 ± 3.3	145 ± 3.6	142 ± 3.1	115 ± 2.6	119 ± 2.3	136 ± 2.1	133 ± 2.9

The enzyme activity was tested under normal conditions after it was incubated in advance with various inhibitors for 20 min at 40°C. The enzyme activity was regarded as 100% without incubating. The influence of enzyme activity by metal ions was measured by testing the enzyme activity with metal ions (5 mM). The enzyme activity was regarded as 100% without metal ions. The enzyme activities indicate the mean of three experiments.