Preparation Of Porous Glass Beads For Carrier And Study On Conditions Of Immobilized Enzyme

To begin with, two kinds of porous glass beads, FXBL and TCBL, were prepared by phase separation and stuffing salts. The beads were used as carrier for immobilizingα-amylase by aborption, convalent binding and diazotization-coupling methods. And meanwhile, the three methods were compared through effect of immobilization, so one of them, the convalent binding method, was picked out and studied in detail, then the optimal conditions of the immobilization and application are obtained. After then, the properties of immobilization ofα-amylase were studied . Secondly , effect of making porous glass bead process on immobilizedα-amylase was studied . Finally, porous glass beads were used as carrier for immobilizing catalase and glutamic acid decarboxylase, so the effectiveness of porous glass beads as carrier was verified. The main conclusion is followed as:(1) The mean diameter of FXBL is 1.48mm and TCBL is 1.49mm. Erosion Ratio of FXBL is 33.65%. In terms of FXBL and TCBL, Strength is 32 kg /cm~2 and 26kg /cm~2, and Water Absorption is 27.37% and 25.32%, and Bulk Density is 1.34 g/cm~3 and 1.37 g/cm~3, and Apparent Porosity is 33.60% and 31.87%.(2)It is 3h that the optimal bead surfaces treatment time byγ-aminopropyl triethoxy silane. It is 3% that the optimal concentration of glutaraldehyde which activates alkylamine glass beads TCBL's surface , so is 2% to FXBL.(3)The optimal conditions of the immobilization ofα-amylase , by convalent binding, is as followed: temperature is 10℃, pH is 6.2, the load of enzyme is 2. 6g/L(to TCBL) and 2. 4g/L(to FXBL) , time is 12h.(4)the optimal application conditions of theα-amylase that immobilized by convalent binding is as followed: temperature is 75℃, and temperature being 5℃higher than the freeα-amylase , pH is 5.2 (to TCBL )and 5.4 (to FXBL), and pH value reducing 0.6 (to TCBL) and 0.8 (to FXBL)unit than the freeα-amylase.(5)Fundamental properties of immobilizedα-amylase is as followed: If treating 1h at 80℃, the activity of immobilizedα-amylase would decline less than 7%, and the activity of freeα-amylase would be reduced to 63%, obviously, the thermal stability of immobiliziedα-amylase is excellent than freeα-amylase. After immobilized α-amylase is reused 5 (to FXBL) and 8 (to TCBL ) times , their activities can been kept about 60% .(6)Under the optimal immobilizing conditions, immobilizedα-amylase was obtained, and under the optimal applying conditions, the activity of immobiliziiedα-amylase was detected, and experimental results were as follows: the immobilizedα-amylase on TCBL has a total activity 357. 39U/g, a recovery rate 39. 79%, and an expression activity 66.73%. Similarly, they are 324.96U/g, 36.18%, 54. 25% on FXBL(7)Phase Separation at 580°C get the grab on 560℃, after 36h, the time of Phase Separation has little effect on activity of immobilizedα-amylase. Hole reamed by 0.3 mol/L potassium hydroxide solution is the most effective. After hole is eroded by 0. 3 mol/L hydrochloric acid solution , immobilizedα-amylase has the maximum activity.(8)Generality of porous glass as carrier is dependent on the state which their surfaces are. modified.