Electrical flocculation was investigated* for separation and extraction of α-amylase BF7658 from a bearing solution

prepared from its crude powder products via leaching. The factors related to the effectiveness of electrical flocculation such as pH value

strength of electrical field (E) and its duration time (t)

the initial concentration of a-amylase (c0) and the dosage of flocculant (W) were studied systematically: 1. Under optimum conditions

i.e. E=8V/cm

t= 15min

pH=6.5

c0 = 2600u/ml

W = 200ppm

the activity of amylase can be recovered no less than 90%

the loss of activity can be reduced to no more than 5%

the activity of flocproduct can be no less than 250000u/g. 2. The selectivity of electrical flocculation depends on the difference of pH values between the enzyme to be separated and other proteins involved

the specific affinity between the flocculant and the enzyme to be separated. 3. Although the electrical field can increase the recovery of a-amylase and decrease the loss of activity obviously

electrical flocculation can not take place

without flocculant in the solution.