Effects of various factors, such as pH, ionic strength, glutaraldehyde concentration, enzyme amount and immobilization time, on enzyme activity were investigated. The immobilization conditions were optimized by orthogonal experiments. Characterizations of immobilized nuclease p1 were also evaluated. Through orthogonal optimization, the optimal immobilization conditions were as follows: pH 5.6, ionic strength 0.125, glutaraldehyde concentration 0.20% and immobilization time 2.0 h. Optimal pH of immobilized enzyme was 5.8. Optimal temperature of immobilized enzyme was 70ºC. Thermal, operational and storage stabilities of the enzyme were improved after it was immobilized on DEAE cellulose. Michaelis constant Km of immobilized enzyme at 69ºC was found to be 27.21 g/l by the Lineweaver-Burk plot.
DEAE cellulose; Nuclease p1; Immobilization; Characterization
