电场絮凝提取碱性蛋白酶的研究

STUDIES ON EXTRACTION OF ALKALINE PROTEINASE 2709 BY ELECTRICAL FLOCCULATION

为了提高工业酶制剂生产的经济效益,本文提出了应用电场絮凝技术提取酶的新工艺。交、直流电场对碱性蛋白酶2709滤清液作用结果表明:直流电场作用更有助于稳定酶活性。在交流电场或直流电场作用下,借助不同絮凝剂,碱性蛋白酶能明显地从溶液中絮凝析出,且絮凝物活性可达4×10~5单位/克,酶回收率可达85%以上。

Experiments of flocculation separation of alkaline proteinase 2709 from supernatant solution using cationic flocculant F_1 in A.C electrical field and anionic flocculants F_2 and F_3 in D.C. electrical field were carried out to study the effects of operating factors, such as the strength of electrical field (E), reaction time (t), pH of the solution, dosage of flocculants (F_1, F_2, F_3), the initial concentration of feed liquid(C_0). Application of electrical field in the supernatant solution of 2709 leads to alteration of loss of activity of 2709 as compared with the product without electrical field applied: 69/0 decrease for D.C. and 90% increase for A. C.When A.C.electrical field was applied on the following conditions. C_0=3205 units/ml, t=30min, E=30V/cm, pH=7.5,F_1=0.4% and the concentration of Na_2SO_4=0.2%, about 85% of 2790 was recovered. About 88% of 2709 was flocculated from the solution under the suitable conditions, for example, C_0=4200 units/ml, pH=6.0, E=12V/cm (D.C.),t=15 min,F2=390 ppm. Those results show that D.C. electrical flocculation is better than A.C. electrical flocculation, but both flocculations can produce flocs of 2709 with activity up 400,000 units/gram. The mixture of F_2,F_3 used in D.C. electrical flocculation is able to reduce consumption of F_2 and increase the recovery of 2709. This study shows that electrical flocculation is advantageous in the process of recovering alkaline proteinase 2709. Due to small dosage and low price of flocculants, this process can be economically profitable.