JPH04193740A - Porous glass carrier for fixing enzyme - Google Patents

Abstract

PURPOSE:To provide a porous glass having excellent strength, heat resistance, etc., suitable to carrier for fixing enzyme by using CaO, TiO2, P2O5 and Na2O as materials, and dipping crystallized glass manufactured therefrom with the specific manufacturing method into acid to make the glass porous. CONSTITUTION:The CaO, TiO2, P2O5 and Na2O are mixed at 45:25:30:2 in mol ratio. Successively, the mixed material is fused at 1300-1400 deg.C and after cooling, crystal nuclei are formed at 650-750 deg.C and further, the crystal nuclei are grown at 730-780 deg.C to manufacture the crystallized glass. Successively, this crystallized glass is dipped into an acid, and by making said glass, the objective porous body having excellent alkali resistance is manufactured. Then, this porous body is used as the carrier for fixing enzyme and the enzyme is combined to execute fixing enzyme reaction. By using this carrier as the carrier for bioreactor, scale up of apparatus is facilitated, and the heat-sterizable and reusable carrier can be obtd.

Description

[Detailed Description of the Invention] 3.1 Industrial Application Fields A bioreactor system using a biocatalyst is attracting attention as a new chemical production technology because it saves resources, saves energy, and is environmentally friendly.

In constructing such a bioreactor system, the development of enzyme-immobilized carriers is an important fundamental technology. Inorganic materials have high mechanical strength and chemical durability, and can be easily heat sterilized, making them excellent materials as enzyme immobilization carriers. Generally, enzymes are immobilized by introducing an organic functional group into the hydroxyl group on the surface of the carrier, and then covalently bonding the organic functional group to the enzyme. A highly siliceous (S102) porous glass carrier has already been developed as an enzyme immobilization carrier using a covalent bonding method, but its use has been limited because it is expensive and lacks durability in an alkaline environment. .

3.2 Conventional techniques and their problems Conventionally, polymer gels such as polysaccharides and acrylamide, ion exchange resins, and synthetic resins such as nylon have been frequently used as carriers for enzyme immobilization for research purposes.

However, these polymeric materials are difficult to heat sterilize and have low material strength, making it difficult to scale up and prevent contamination, making it difficult to use them as enzyme immobilization carriers for bioreactors on an industrial scale. Furthermore, although highly silica porous glass carriers have high mechanical strength and heat resistance, their use has been limited due to their high price and high disintegration in alkaline environments.

Thus, a carrier for enzyme immobilization that can be used in industrially applicable bioreactors has not yet been developed.

An object of the present invention is to provide an inorganic carrier for enzyme immobilization that has high mechanical strength, heat resistance that can withstand easy heat sterilization, excellent economic efficiency, and high alkali resistance, and a method for producing the same. be.

3.3 Means for solving the problem As a result of intensive research into inorganic materials in order to achieve the above object, the present inventors found that 45CaO-25TiO7-30P
It has been found that a porous glass obtained by acid-treating crystallized glass produced by mixing a small amount of Na2O with 2O5 has excellent alkali resistance. Also, Na2
Mix O at an optimal ratio of 2 mo1% and heat at 1300°C.
Melt at ~1400℃ and cool it down to 6500C~
Crystal nucleation at 700°C and 730°C to 780°C
A porous material excellent in immobilizing enzymes can be obtained by acid-treating crystallized glass that has grown crystal nuclei at ℃.

When the enzyme was immobilized on this material, the reaction efficiency was high and the enzyme could be stably supported for a long period of time.

In addition, in the present invention, 45CaO-25TiO2-30
By using a mixture of P2O5 and Na2O, it was possible to produce a porous glass carrier with excellent alkali resistance, pore size, specific surface area, and enzyme binding properties suitable for enzyme immobilization.

3.4 Effects of the Invention The glass carrier for enzyme immobilization obtained by the present invention has high mechanical strength and excellent heat resistance, making it easy to scale up the device when used as a carrier for a bioreactor. It is excellent in heat sterilization and carrier reuse, and thus opens the way to the use of bioreactors on an industrial scale.

Furthermore, the porous carrier obtained by the present invention can have a porous structure with a preferable pore distribution depending on the molecular weight of the enzyme used, since the pore distribution and specific surface area can be controlled by acid treatment conditions. can be manufactured. In addition, since it has high alkali resistance and can stably support enzymes for a long period of time even in an alkaline environment, it is an inorganic carrier that is industrially more useful than conventional immobilized carriers.

3.5 Example Next, examples will be shown to demonstrate the effects of this invention.

Example 1 45Ca○-25Ti○2-30P2O5 system, Na
Mix 1 mo1% of 2O and synthesize crystallized glass with 0
, IN = central pore radius 10 nm to 2 On after soaking in hydrochloric acid
A porous body having a specific surface area of 75 to c+om''/g was produced.

When β-galactosidase and alkaline protease were immobilized on this product by the glutaraldehyde method, it showed good enzyme immobilization ability and stability of the immobilized enzyme.

Furthermore, when immobilized alkaline protease is continuously used in an aqueous solution at pH 9, the stability of the enzyme is 4 to 7 times higher than when immobilized on a conventional porous glass carrier containing S102 as the main component. It increased to

First Example 2 45 CaO25T 10230 P2O5 system was mixed with 2m01% of Na2O, and the synthesized crystallized glass was immersed in 0, IN-hydrochloric acid to give a central pore radius of 15 nm to 25 nm.
A porous body with a specific surface area of 70 to som2/g was produced.

When β-galactosidase and alkaline protease were immobilized on this product by the glutaraldehyde method, it showed good enzyme immobilization ability and stability of the immobilized enzyme.

Furthermore, when immobilized alkaline protease is continuously used in an aqueous solution at pH 9, the stability of the enzyme is 4 to 7 times higher than when it is immobilized on a conventional porous glass carrier mainly composed of SiC2. It increased.

Example 3 To the system of 45CaO-25Ti○2-30P2O5, Na
Mix 1 mo1% of 2O and synthesize the crystallized glass with 0
, IN-hydrochloric acid immersion to have a central pore radius of 2 Onm to 30 nm
A porous body having a specific surface area of 60 to 70 m27g was produced.

When β-galactosidase and alkaline protease were immobilized on this product by the glutaraldehyde method, it showed good enzyme immobilization ability and stability of the immobilized enzyme.

When immobilized alkaline protease is continuously used in an aqueous solution at pH 9, the stability of the enzyme increases 3 to 6 times compared to when it is immobilized on a conventional porous glass support mainly composed of SiO2. did.

Claims (1)

[Claims] 1. Calcium oxide (CaO) and titanium dioxide (TiO
_2), diphosphorus pentoxide (P_2O_5), and disodium oxide (Na_2O) at an optimal molar ratio of 45:25:30:2, melted at 1300°C to 1400°C, and then melted at 650°C to 700°C. A porous body having excellent alkali resistance is produced by immersing crystallized glass produced in two steps at 730°C and 730°C to 780°C in acid to make it porous. An enzyme is bound to this material to perform an immobilized enzyme reaction.