IL44510A - Cellulose fibers containing enzymes and their preparation - Google Patents

Description

44510/2 ΟΠ- Π 0»0»T3R 0* »30Π Π»ΚΠ »3*0 Cellulose fibers containing enzymes and their preparation SNAMPROGETTI S.p.A Inventors i Dinolpinelli Francesco Bartoli Silvio Gulinelli C. 42685 This invention relates to cellulosic bodies incorporating enzymes, and more particularly to cellulosic filaments incorporating enzymes; i ^p<, as well as to the production of such bodies.

It is known that a great number of reactions, which otherwise cannot be performed or need drastic operating conditions, can be carried' out when catalyzed by enzymes.

It is also known that use may be made of bodies, particularly filaments, which incorporate enzymes which carry out their catalytic activity without spreading into the reaction mass.

The enzyme-incorporating filaments can be prepared starting from a solution of a polymer capable of forming a filament; enzymatic compounds are dispersed in the solution of the polymer in the form of very small drops "of the order of magnitude of an emulsion. This emulsion may be wet or dry spun to produce a filament possessing, in its interior, very small cavities which contain the enzyme so that the latter is separated from the environment by a very thin polymeric membrane.

Israel Patent Specification No. 2406 discloses the production of 'enzyme-incorporating filaments, starting from polymers such as, for example, cellulose derivatives. It appears that it is not practicable to form the filaments from cellulose itself because of the difficulties encountered during the subsequent spinning operations of the cellulose.

The present invention is "based on the discoveries thatj whereas it is not practicable to start the production with cellulose ,· it is practicable to form the filamentary body from a cellulose derivative which can be reconverted to cellulose after spinning, and that a filamentary body produced in this way has a permeability greater than that of a body formed of a cellulose derivative. Moreover, the increased permeability enables an enzyme incorporated in the body to have an increased effective activity.

In fact, the catalytic activity of the enzyme contained in the filament is effected by the resultant spreading processe and it is for this .reason that the enzymatic activity depends on the permeability.

One aspect of the present invention provides a permeable filamentary body formed of cellulose and having an enzyme distributed in finely divided form throughout the body.

A further aspect of the present invention provides a 44510/2 a process for producing the permeable filament, which process comprises mixing a solution of a nitrocellulose in a solvent Immiscible vith water, with a solution in water of an enzyme, emulsifying the resulting mixture, spinning and coagulatin the resulting emulsion to produce a filament incorporating the enzyme, and treating the filament with a reducing agent capable of removing the nltro substituents of the nitrocellulose of the filament under conditions which are not detrimental to the enzyme, thereby making permeable the filament.

She product of the process for producing the permeable filament has a permeability much higher than that of the substituted cellulose base filament. Shis process Involves a chemical modification of the filamentary material by means of the reducing agents, under operating conditions that do not damage the enzyme.

A preferred starting material is high molecular weight nitrocellulose with such a nitrogen content that it is substantially soluble in organic solvents, preferably higher than 5 . She nitrocellulose is dissolved in a solvent which is immiscible with water, preferably selected from n-butyl acetate, bis-butyl phthalate, methyl amyl ketone and ethyl amyl ketone. These or other solvents can be employed as such or suitably diluted by one or more diluents selected from aliphatic hydrocarbons such as pe tane, hexane, heptane or octane aromatic hydrocarbons such as toluene and xylene; and hydrocarbon mixtures such as llgroln.

Examples of enzymes which can be incorporated in the r-/ filaments or other bodies include urease, invertase, lactase, acylase, transaminase, glucose-oxidase , catalase, papain* tryptophansynthetase and penicillin acylase.

As alternatives to .dispersing a solution of the enzyme in the polymer solution, other processes can be performed in order to prepare filaments incorporating the enzyme. For instance, the enzyme can be dispersed, as a powder, into the nitrocellulose polymer which will be then spun according to known techniques. The resulting filament can be reacted with a reducing agent which removes the nitrogroup and forms the 1 cellulose filament incorporating the enzyme.

As a reducing agent use can be made of an ammonium sulphide solution with or without excesses of ammonia or hydrogen sulphide.

The followin Examples illustrate the present invention.

EXAMPLE 1 1000 Grams of nitrocellulose (produced by Snia Viscosa S.p.A.) were dissolved in a solvent mixture constituted by 6,900 g. of n-butylacetate and 4,600 g. of toluene. To the resulting solution was added an aqueous solution containing 1 1,600 g. of the enzyme invertase.

Under stirring, an emulsion was obtained which was spun through orifices having a 125μ diameter, and coagulated in a coagulating agent constituted by a mixture of saturated hydrocarbons having boiling points in the range from 40 to 0 C About 2,600 g. of enzyme-encasing filaments were obtained. 1 ,000 Grams of these filaments, immersed in a 20% saccharose solution having-.la pH of 4.5 , inverted 4.0 g. of sugar per minute. > Another 1 ,000 g. of enzyme-encasing filaments were treated with a 2% ammonia solution which had been saturated wit hydrogen sulphide to a pH of 8.5. After treatment for 6 hours, the treated filaments were washed and, when subsequently immersed in a 20 saccharose solution having a pH of 4. invert 490 g. of sugar per minute under the. same conditions as the ( untreated filaments.

EXAMPLE 2 1 ,000 Grans of nitrocellulose (produced by Snia Viscosa S.p.A.) were dissolved, at room temperature, in a mixture constituted by 7 ,000 g. of n-butylacetate and 3 * 50 g. of tolue An aqueous solution of 2 ,000 g. of the enzyme invertase was added to the resulting solution. An emulsion was obtained unde stirring: at 1 C the emulsion was spun through orifices having a 125μ diameter and coagulated, at 20°C, in a mixture of saturate hydrocarbons having the boiling points in the range from 60 to 80°C. About 3,000 g. of enzyme-encasing filaments were obtaine 1 ,000 Grams of these filaments, when immersed in a 20% saccharose solution having a pH of 4. 5 » inverted 05 6· . ° suga per minute.

Another 1 ,000 g. of filaments were treated for 6 hours with an ammonia solution saturated with hydrogen sulphide as ■ . . . r described in Example 1 . After the treatment, the resulting filaments when immersed in a saccharose solution similar to that described in the preceding Example, inverted 1890 g. of sugar per minute.

EXAMPLE .- 1 ,000 Grams of nitrocellulose (produced by Snia Viscosa S.p.A.) were dissolved in a mixture constituted by 7 »000 g. of n-butylacetate and 3 »750 g« of toluene. Then, an aqueous solution of 2 ,000 g. of the enzyme penicillin acylase was added to the resulting solution, and the whole was stirred to form an emulsion, The emulsion was spun according to the procedure described in Example.1 , and 3 » 000 g. of enzyme-encasing filaments were ■ · . ' ■ obtained. .■· ■ - · . { 1 , 500 Grams of these filaments were immersed in 37· 5 litr of a 10 —1 M potassium phosphate solution having a pK of 8.0 and containing 1 , 500 g. of potassium penicillin G, at 37°^ · The enzyme contained in the filaments catalyzed the hydrolysis of penicillin to 6-aminopenicillanic acid and phenylacetic acid.

During the reaction the pH was kept constant by adding sodium hydroxide' as required. In this way, a % conversion of penicillin was obtained after 227 minutes. j An aqueous solution of 2 ,000 g. of the enzyme penicillin-acylase was mixed with a solution (similar to that described above) of 1 ,000 g. of nitrocellulose in n-butylacetate and toluene, and the resulting emulsion was spun and coagulated.

The resulting enzyme-casing filaments were treated in the ammonia solution saturated with hydrogen sulphide as described in Example 1 . . ,500 G. of the treated filaments, under the same-conditions as the untreated filaments, promoted the conversion of 90% of penicillin over 56 minutes.

An aqueous solution of 2 ,000 g. of penicillin-acylase was dispersed in a solution formed by dissolving 1 ,000 g. of cellulose triacetate in 13 , 300 g. of methylene chloride. The resulting emulsion was spun according to. the procedure of Example 1 , the coagulant "being toluene. 1 ,000 Grams of the resulting filaments, immersed at 37° in litres of a -1 25 10 M potassium phosphate solution having a pH of 8.0 and containing 10% potassium penicillin G, hydrolyzed 90 'of the penicillin after 219 minutes. 1000 Grams 'of 'these untreated filaments, under the 'same conditions, hydrolyzed 0% of the penicillin after .298 minutes.

Claims (9)

CLAIMS:

1. A permeable filamentary body formed of cellulose Kj and having an enzyme distributed in finely divided form throughout the body.

2. A process for producing a permeable filamentary body as claimed in Claim 1,, which process comprises mixing a solution of a nitrocellulose in a solvent immiscible with water, with a solution in water of an enzyme, emulsifying the resulting mixture, spinning and coagulating the resulting emulsion to produce a filament incorporating the enzyme, and treating the filament with a reducing agent capable of removing the nitro substituent of the nitrocellulose of the filament under conditions which are not detrimental to the enzyme, thereby makin permeable the filament.

3. process according to Claim 2, wherein the conversion of the nitrocellulose to cellulose is effected with a solution of ammonium sulphide,

4. A process according to Claim 2 or 3» wherein the solvent in which the nitrocellulose is dissolved is selected from n-butyl acetate, bis-butyl phthalate, methyl amyl ketone and ethyl amyl ketone.

5. A process according to any one of Claims 2 to 4, wherein the nitrocellulose is dissolved in a solvent immiscible with water, which solvent is diluted by one or more diluents selected from aliphatic hydrocarbons and aromatic hydrocarbons.

6. A process according to any one of Claims 2 to 5» wher in the enzyme is selected from urease, invertase, lactase, acylase, transaminase, glucose-oxidase, catalase, : papain, tryptophansynthetase and penicillin acylase.

7. A process according to Claim 2, substantially as described In any one of the foregoing Examples.

8. A permeable filamentary body according to Claim 1, substantially as hereinbefore described.

9. A permeable filamentary body whenever produced by a process accordin to Claim 2. ND:dn