CA1036966A - High permeability cellulose fibers containing enzymes and process for the preparation thereof - Google Patents
High permeability cellulose fibers containing enzymes and process for the preparation thereofInfo
- Publication number
- CA1036966A CA1036966A CA195,673A CA195673A CA1036966A CA 1036966 A CA1036966 A CA 1036966A CA 195673 A CA195673 A CA 195673A CA 1036966 A CA1036966 A CA 1036966A
- Authority
- CA
- Canada
- Prior art keywords
- enzyme
- process according
- solution
- organic solvent
- fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N11/00—Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
- C12N11/02—Enzymes or microbial cells immobilised on or in an organic carrier
- C12N11/04—Enzymes or microbial cells immobilised on or in an organic carrier entrapped within the carrier, e.g. gel or hollow fibres
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
- D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
- D01F2/08—Composition of the spinning solution or the bath
- D01F2/10—Addition to the spinning solution or spinning bath of substances which exert their effect equally well in either
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Zoology (AREA)
- Genetics & Genomics (AREA)
- Biochemistry (AREA)
- Textile Engineering (AREA)
- Biotechnology (AREA)
- Biomedical Technology (AREA)
- General Engineering & Computer Science (AREA)
- General Health & Medical Sciences (AREA)
- Dispersion Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Microbiology (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
- Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
- Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
- Artificial Filaments (AREA)
- Medicinal Preparation (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
Embedded-enzyme cellulose fibers presenting a high permeability degree are obtained starting from a non-regenerated cellulose derivative, by dissolving a nitrocellulose polymer into a water-insoluble organic solvent, adding to the solution thus obtained an aqueous solution of an enzyme to form, under stirring, an emulsion which is then spun and coagulated, and treating the resulting fibers with a reducing agent. The embedded-enzyme cellulose fibers are particularly suitable for use in enzyme catalysed reactions.
Embedded-enzyme cellulose fibers presenting a high permeability degree are obtained starting from a non-regenerated cellulose derivative, by dissolving a nitrocellulose polymer into a water-insoluble organic solvent, adding to the solution thus obtained an aqueous solution of an enzyme to form, under stirring, an emulsion which is then spun and coagulated, and treating the resulting fibers with a reducing agent. The embedded-enzyme cellulose fibers are particularly suitable for use in enzyme catalysed reactions.
Description
10~6966 The present invention relates to a process for the preparation of embedded-enzyme cellulose fibers presenting a high permeability degree.
It is known thatmany reactions, which otherwise might not take place or would need more drastic operative conditions, can be carried out when catalyzed by enzymes.
In this context, it is also known to use fibers containing enzymes which carry out their catalytic activity without the enzymes being introduced into the reaction medium.
The inclusion of the enzyme is generally carried out by employing a fiber constituted by an articificial or synthetic polymeric material. The embedded-enzyme fibers can be prepared starting from polymeric solutions adapted to give fibers wherein enzymatic compounds are dispersed in the form of very small drops into emulsions. The emulsion thus obtained may be wet or dry spun to produce a fiber presenting, in its interior, very small cavities containing the enzymes which are separated from the environment by a very thin membrane.
The enzymes-containing fibers which have been employed up to date, such as the type described in Canadian Patent No.
940,069 of January 15, 1974 to the Applicant, are obtained starting from polymers adapted to give fibers such as, for instance, cellulose derivatives; however, nothing is known about the fact that they can be prepared starting just from non-regenerated cellulose because of the difficulties this latter showed when subjected to the subsequent spinning processes.
The embedded-enzyme cellulose fibers present the advantage, with respect to the other kinds of fibers, of having a higher activity as to the enzymatic reactions, becauseof the increased permeability of the fiber itself. In fact, the catalytic action of the enzymes contained in the fibers is affected by the technique of enzyme introduction and, therefore, theenzymatic activi-~036966 ty depends on the permeability. It is not always possible to obtainhighly permeable ~nzymes-containinc3 fibers by simply modifying the fiber preparation conditions, owing to the fact that, at high enzyme concentrations, the permeability is still a limiting factor.
It has now been found and this is an object of the present invention, that it is possible to prepare embedded-enzyme cellulose fibers presenting a high permeability degree, starting from a non-regenerated cellulose derivative. The process according to the invention is characterized in that it comprises dissolving a nitrocellulose polymer into a water-insoluble organic solvent, adding to the polymer solution thus obtained an aqueous solution of an enzyme to form, under stirring, an emulsion which is then spun and coagulated, and treating the resulting fibers with a reducing agent. A non-substituted cellulose base fiber containing the enzyme is thereby obtained, which has a permeability much yreater than that of the starting substituted cellulose base fiber.
The process according to the present invention is funda-mentally based on a chemical modification of the starting fibrous material by the action of reducing agents which do not damage the embedded enzyme.
The process of the invention enables one to overcome the aforementioned drawbacks and to obtain, after the reduction - treatment, enzymes-containing cellulose fibers presenting a high permeability degree.
The starting material advantageously employed consists of high molecular weight nitrocellulose having a nitrogen content sufficient to allow the polymer to be substantially soluble into organic solvents; such nitrogen content is preferably higher than 5%.
The nitrocellulose polymer is dissolved into a water-insoluble organic solvent, preferably selected among n-butyl-ace-tate, bis-butylphthalate, methylamylketone, ethylamylketone and the like, which can be employed as such or suitably diluted by aliphatic hydrocarbons such as pentane, hexane, heptane and oc-B~
~036~
tane, aromatic hydrocarbons such as toluene and xylene, or hy-drocarbon mixtures such as ligroin.
To the cell~1ose solution thus obtained is added an aqueous solution o~ aD enzyme which may be selected from a wi-de class ~or instance, use may be made of urease, invertase, lactase, acylase, transaminase, glucose-oxidase, catalase, pa-pain, t~yptophansynthetase, penicillin acylase and some o-thers.
The emulsion is then spun accordingto known techniques by u~ing known coagulants such as, for instance, those cited in the abovementioned Canadian patent.
Besides using emulsions in order to disperse the enzy-me into the polymer solution,other processes can be employed to prepare such enzymes~containing fi~ers. For instance, tlle enzy-me may be dispersed as a powder~ into the polymer which will be then spun according to known methods.
The fibers thus obtained are then reacted with a re-ducing agent to remove t~e ni~ro groups contained therein and to obtain the sought embedded-enzyme cellulose fibers. As redu-cing agents, use may be made of ammonium sulfohydrate ~olutions optionally containing slight e~cesses of a~monia or hydrogen sulphide.
The invention will be better illustrated with reference to the following non-restrictive examples.
EXAMPLæ 1 1,000 g of nitrocellulose (of Snia Viscosa S.p.A.) were dissolved into a solution consisting of 6,900 g of n-butylaceta-te and 4,600 g of toluéne, Then, 1,600 g of an aqueous solution of an invertase enzyme were added to obtain, unaer stirring, ~J
emulsion. The emulsion was spun through orifices having diame-~ers of 125 ~ and coagulated intoamixture of saturated hydrocar-bons having ~oiling points ranging from 40 to 70C, 1,000 g of the fiber thus obtained were immersed into a 20~o saccharose solution having a pH of 4.5, and inverted 40 g :~1 of sugar per minute, 1036966 1,000 g f the same fiber were treated with a 2% am-monia solution satura-ted ~ th hydrogen su.lphide up to a pH of 8~5. After 6 reaction hours, this second fiber was washed and, when immersed into a 20~o saccharose solution having a pH of 4.5, it inverted 490 g of suger per minute.
EXAMPI~ 2 1,000 g of nitrocellulose (of Snia Viscosa S.p.A,) were dissolved, at room tempera~ure, into 7,000 g of n-butylace-1û tate and 3,750 g of tolu~ne, 2,000 g of an aqueous solution of an lnvertase enzyme were added to the solution to obtain, under stirri.ng, an emulsion which was then spun at 1C through orifi-ces having diameters of 125 ,u and coagul~ted, at ~0C, into a mixture ofsaturatedhydrocarbons having boiling poi~ts ranging from 60 to 80C. About 3,000 g of fiber were obtai.ned.
1 3UOO g of t~is fiber, immersed in a 2C~o saccharose solutio.n having a pH of 4.5, inverted-505 g of sugar per mi~ute.
1,000 gof the same fiber were treated for 6 hours, with an ammo.nia solutio.n saturated with hydroge.n sulphide ac-cording to example 1. After the treatment, the resulting fiber.
when immersed into the same saccharose solution as above, in-verted 1890 g of sugar per mlnute.
1,000 gof nitrocellulose (of Snia Viscosa S.p.A.) were dissolved into a mix-ture consisting of 7,000 g of n-butylacetate and 3,750 g of toluene. ~hen 2,000 g of an aqueous solution of a penicillin acylase enzyme were added and th~ whole was stir-red to obtain an emulsion. The emulsion was spun according to : example 1 and 3,000 g of fiber were obtained.
1,500 g of this fiber were i~mersed i.nto 37.5 liters of a 10 1 M potassium phosphate solution having a pH of 8.0 and containing 1,50û g of potassium penicillin G,at 37C. ~he enzy-me contained in the fiber catalyzed the hydrolysis of penicillin ~ 036966 to 6-aminopenicill~nic acid and phcnyl-acetic acid ~uring tile reaction, the p~l was kept cons-tant by adding sodium hydroxide.
A penicillin conversion of 90~0 was thereby obtained after 227 minute3, 1,000 g of nitrocellulose were treated with 2,000 g of an aqueous solution o~ a pcnicillin-acylase enzyme according to the above method to obtain a fiber which was then -trea-ted wi-th an ammonia solution saturated with hydrogen sulphide ac-cording to ecample 1. ~he resulting fiber was denoted as fi-ber A.
An equal solution of penicillin-acylase was dispersed into a solution formed by dissolving 1,000 g of cellulose tri~-cetate into 13,300 g of methylene chloride. ~he emulsion ob-tained was spun according to example 1, the coagulant used being toluene. The resulting fiber was denoted as fiber ~.
1,000 g of fiber A were immersed at 37C into 25 li-ters of a 10 M potassium phosphate solution having a pH of 8.0 and containing 10% of potassium penicillin G, and hydrolyzed 90~o of penicillin over 219 minutes.
Fiber ~,under the same conditions, hydrolyzed 90~0 of penicillin over 298 minutes.
1,500 g of fiber ~ were treated with an ammonia solu-tion saturated with hydrogen sulphide according to example 1.
~he resulting fiber,under the same conditions of the untreated fiber, promoted a penicillin conversion of goc,b over 56 minutes.
It is apparent that the aforesaid advantages obtained with the fibers of the invention may be extended to films, mi-crocaps~es or similar products containing enzymes. ~he largein-terest of the ~pplicant resides however in the peculiar fiber field.
~, .
It is known thatmany reactions, which otherwise might not take place or would need more drastic operative conditions, can be carried out when catalyzed by enzymes.
In this context, it is also known to use fibers containing enzymes which carry out their catalytic activity without the enzymes being introduced into the reaction medium.
The inclusion of the enzyme is generally carried out by employing a fiber constituted by an articificial or synthetic polymeric material. The embedded-enzyme fibers can be prepared starting from polymeric solutions adapted to give fibers wherein enzymatic compounds are dispersed in the form of very small drops into emulsions. The emulsion thus obtained may be wet or dry spun to produce a fiber presenting, in its interior, very small cavities containing the enzymes which are separated from the environment by a very thin membrane.
The enzymes-containing fibers which have been employed up to date, such as the type described in Canadian Patent No.
940,069 of January 15, 1974 to the Applicant, are obtained starting from polymers adapted to give fibers such as, for instance, cellulose derivatives; however, nothing is known about the fact that they can be prepared starting just from non-regenerated cellulose because of the difficulties this latter showed when subjected to the subsequent spinning processes.
The embedded-enzyme cellulose fibers present the advantage, with respect to the other kinds of fibers, of having a higher activity as to the enzymatic reactions, becauseof the increased permeability of the fiber itself. In fact, the catalytic action of the enzymes contained in the fibers is affected by the technique of enzyme introduction and, therefore, theenzymatic activi-~036966 ty depends on the permeability. It is not always possible to obtainhighly permeable ~nzymes-containinc3 fibers by simply modifying the fiber preparation conditions, owing to the fact that, at high enzyme concentrations, the permeability is still a limiting factor.
It has now been found and this is an object of the present invention, that it is possible to prepare embedded-enzyme cellulose fibers presenting a high permeability degree, starting from a non-regenerated cellulose derivative. The process according to the invention is characterized in that it comprises dissolving a nitrocellulose polymer into a water-insoluble organic solvent, adding to the polymer solution thus obtained an aqueous solution of an enzyme to form, under stirring, an emulsion which is then spun and coagulated, and treating the resulting fibers with a reducing agent. A non-substituted cellulose base fiber containing the enzyme is thereby obtained, which has a permeability much yreater than that of the starting substituted cellulose base fiber.
The process according to the present invention is funda-mentally based on a chemical modification of the starting fibrous material by the action of reducing agents which do not damage the embedded enzyme.
The process of the invention enables one to overcome the aforementioned drawbacks and to obtain, after the reduction - treatment, enzymes-containing cellulose fibers presenting a high permeability degree.
The starting material advantageously employed consists of high molecular weight nitrocellulose having a nitrogen content sufficient to allow the polymer to be substantially soluble into organic solvents; such nitrogen content is preferably higher than 5%.
The nitrocellulose polymer is dissolved into a water-insoluble organic solvent, preferably selected among n-butyl-ace-tate, bis-butylphthalate, methylamylketone, ethylamylketone and the like, which can be employed as such or suitably diluted by aliphatic hydrocarbons such as pentane, hexane, heptane and oc-B~
~036~
tane, aromatic hydrocarbons such as toluene and xylene, or hy-drocarbon mixtures such as ligroin.
To the cell~1ose solution thus obtained is added an aqueous solution o~ aD enzyme which may be selected from a wi-de class ~or instance, use may be made of urease, invertase, lactase, acylase, transaminase, glucose-oxidase, catalase, pa-pain, t~yptophansynthetase, penicillin acylase and some o-thers.
The emulsion is then spun accordingto known techniques by u~ing known coagulants such as, for instance, those cited in the abovementioned Canadian patent.
Besides using emulsions in order to disperse the enzy-me into the polymer solution,other processes can be employed to prepare such enzymes~containing fi~ers. For instance, tlle enzy-me may be dispersed as a powder~ into the polymer which will be then spun according to known methods.
The fibers thus obtained are then reacted with a re-ducing agent to remove t~e ni~ro groups contained therein and to obtain the sought embedded-enzyme cellulose fibers. As redu-cing agents, use may be made of ammonium sulfohydrate ~olutions optionally containing slight e~cesses of a~monia or hydrogen sulphide.
The invention will be better illustrated with reference to the following non-restrictive examples.
EXAMPLæ 1 1,000 g of nitrocellulose (of Snia Viscosa S.p.A.) were dissolved into a solution consisting of 6,900 g of n-butylaceta-te and 4,600 g of toluéne, Then, 1,600 g of an aqueous solution of an invertase enzyme were added to obtain, unaer stirring, ~J
emulsion. The emulsion was spun through orifices having diame-~ers of 125 ~ and coagulated intoamixture of saturated hydrocar-bons having ~oiling points ranging from 40 to 70C, 1,000 g of the fiber thus obtained were immersed into a 20~o saccharose solution having a pH of 4.5, and inverted 40 g :~1 of sugar per minute, 1036966 1,000 g f the same fiber were treated with a 2% am-monia solution satura-ted ~ th hydrogen su.lphide up to a pH of 8~5. After 6 reaction hours, this second fiber was washed and, when immersed into a 20~o saccharose solution having a pH of 4.5, it inverted 490 g of suger per minute.
EXAMPI~ 2 1,000 g of nitrocellulose (of Snia Viscosa S.p.A,) were dissolved, at room tempera~ure, into 7,000 g of n-butylace-1û tate and 3,750 g of tolu~ne, 2,000 g of an aqueous solution of an lnvertase enzyme were added to the solution to obtain, under stirri.ng, an emulsion which was then spun at 1C through orifi-ces having diameters of 125 ,u and coagul~ted, at ~0C, into a mixture ofsaturatedhydrocarbons having boiling poi~ts ranging from 60 to 80C. About 3,000 g of fiber were obtai.ned.
1 3UOO g of t~is fiber, immersed in a 2C~o saccharose solutio.n having a pH of 4.5, inverted-505 g of sugar per mi~ute.
1,000 gof the same fiber were treated for 6 hours, with an ammo.nia solutio.n saturated with hydroge.n sulphide ac-cording to example 1. After the treatment, the resulting fiber.
when immersed into the same saccharose solution as above, in-verted 1890 g of sugar per mlnute.
1,000 gof nitrocellulose (of Snia Viscosa S.p.A.) were dissolved into a mix-ture consisting of 7,000 g of n-butylacetate and 3,750 g of toluene. ~hen 2,000 g of an aqueous solution of a penicillin acylase enzyme were added and th~ whole was stir-red to obtain an emulsion. The emulsion was spun according to : example 1 and 3,000 g of fiber were obtained.
1,500 g of this fiber were i~mersed i.nto 37.5 liters of a 10 1 M potassium phosphate solution having a pH of 8.0 and containing 1,50û g of potassium penicillin G,at 37C. ~he enzy-me contained in the fiber catalyzed the hydrolysis of penicillin ~ 036966 to 6-aminopenicill~nic acid and phcnyl-acetic acid ~uring tile reaction, the p~l was kept cons-tant by adding sodium hydroxide.
A penicillin conversion of 90~0 was thereby obtained after 227 minute3, 1,000 g of nitrocellulose were treated with 2,000 g of an aqueous solution o~ a pcnicillin-acylase enzyme according to the above method to obtain a fiber which was then -trea-ted wi-th an ammonia solution saturated with hydrogen sulphide ac-cording to ecample 1. ~he resulting fiber was denoted as fi-ber A.
An equal solution of penicillin-acylase was dispersed into a solution formed by dissolving 1,000 g of cellulose tri~-cetate into 13,300 g of methylene chloride. ~he emulsion ob-tained was spun according to example 1, the coagulant used being toluene. The resulting fiber was denoted as fiber ~.
1,000 g of fiber A were immersed at 37C into 25 li-ters of a 10 M potassium phosphate solution having a pH of 8.0 and containing 10% of potassium penicillin G, and hydrolyzed 90~o of penicillin over 219 minutes.
Fiber ~,under the same conditions, hydrolyzed 90~0 of penicillin over 298 minutes.
1,500 g of fiber ~ were treated with an ammonia solu-tion saturated with hydrogen sulphide according to example 1.
~he resulting fiber,under the same conditions of the untreated fiber, promoted a penicillin conversion of goc,b over 56 minutes.
It is apparent that the aforesaid advantages obtained with the fibers of the invention may be extended to films, mi-crocaps~es or similar products containing enzymes. ~he largein-terest of the ~pplicant resides however in the peculiar fiber field.
~, .
Claims (6)
1. A process for the preparation of embedded-enzyme cellulose fibers presenting a high permeability degree starting from a non-regenerated cellulose derivative,characterized in that it comprises dissolving a nitrocellulose polymer into a water-insoluble organic solvent, adding to the solution thus obtained an aqueous solution of an enzyme to form, under stirring, an emulsion which is then spun and coagulated, and treating the resulting fibers with a reducing agent.
2. Process according to claim 1, characterized in that the nitrocellulose polymer has a nitrogen content of at least 5%.
3. Process according to claim 1, characterized in that the water-insoluble organic solvent is selected from the group comprising n-butylacetate, bis-butylphthalate, methylamylketone and ethylamylketone.
4. Process according to claims 1 or 3, characterized in that the water-insoluble organic solvent contains a diluent selected from the group comprising aliphatic and aromatic hydro-carbon and mixtures thereof.
5. Process according to claim 1, characterized in that the enzyme is selected from the group comprising urease, invertase, lactase, acylase, transaminase, glucose-oxydase, catalase, papain, tryptophansynthetase and penicillin acylase.
6. Process according to claim 1, characterized in that the reducing agent is an ammonium sulfohydrate solution optionally containing a slight excess of ammonia or hydrogen sulphide.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT21944/73A IT987038B (en) | 1973-03-22 | 1973-03-22 | HIGH PER MEABILITY CELLULOSE FIBERS CONTAINING ENZINES AND PROCEDURE FOR THEIR PREPA RATION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036966A true CA1036966A (en) | 1978-08-22 |
Family
ID=11189179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA195,673A Expired CA1036966A (en) | 1973-03-22 | 1974-03-21 | High permeability cellulose fibers containing enzymes and process for the preparation thereof |
Country Status (29)
| Country | Link |
|---|---|
| JP (1) | JPS5438657B2 (en) |
| AR (1) | AR201575A1 (en) |
| AT (1) | AT324265B (en) |
| BE (1) | BE812571A (en) |
| BR (1) | BR7402308D0 (en) |
| CA (1) | CA1036966A (en) |
| CH (1) | CH617719A5 (en) |
| CS (1) | CS193502B2 (en) |
| DD (1) | DD110310A5 (en) |
| DK (1) | DK140146B (en) |
| EG (1) | EG11444A (en) |
| ES (1) | ES424884A1 (en) |
| FR (1) | FR2222383B1 (en) |
| GB (1) | GB1453744A (en) |
| HU (1) | HU171038B (en) |
| IE (1) | IE40379B1 (en) |
| IL (1) | IL44510A (en) |
| IN (1) | IN139465B (en) |
| IT (1) | IT987038B (en) |
| LU (1) | LU69676A1 (en) |
| NL (1) | NL174164B (en) |
| NO (1) | NO138450C (en) |
| PL (1) | PL88670B1 (en) |
| RO (1) | RO86222B (en) |
| SE (1) | SE400974B (en) |
| SU (1) | SU620218A4 (en) |
| TR (1) | TR17899A (en) |
| YU (1) | YU35630B (en) |
| ZA (1) | ZA741842B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1207172B (en) * | 1979-02-15 | 1989-05-17 | Anic Spa | PROCESS FOR THE PREPARATION OF GLOBAL MICROPOROUS BODIES ONE OR MORE ACTIVE AGENTS. |
| JPS55135591A (en) * | 1979-04-09 | 1980-10-22 | Mitsubishi Rayon Co Ltd | Preparation of fixed microorganism |
| GB2189809A (en) * | 1986-05-03 | 1987-11-04 | Michael Storey Otterburn | Immobilized biological material |
| EP0799894B1 (en) * | 1996-02-09 | 2004-05-19 | Degussa AG | Process for the preparation of (S)-Cyanhydrines |
-
1973
- 1973-03-22 IT IT21944/73A patent/IT987038B/en active
-
1974
- 1974-03-12 TR TR17899A patent/TR17899A/en unknown
- 1974-03-15 GB GB1173974A patent/GB1453744A/en not_active Expired
- 1974-03-15 IE IE570/74A patent/IE40379B1/en unknown
- 1974-03-16 EG EG76/74A patent/EG11444A/en active
- 1974-03-18 YU YU730/74A patent/YU35630B/en unknown
- 1974-03-18 NL NLAANVRAGE7403628,A patent/NL174164B/en not_active IP Right Cessation
- 1974-03-19 RO RO78089A patent/RO86222B/en unknown
- 1974-03-20 BE BE142225A patent/BE812571A/en not_active IP Right Cessation
- 1974-03-20 IN IN608/CAL/74A patent/IN139465B/en unknown
- 1974-03-20 NO NO740994A patent/NO138450C/en unknown
- 1974-03-20 HU HU74SA00002611A patent/HU171038B/en unknown
- 1974-03-20 FR FR7409503A patent/FR2222383B1/fr not_active Expired
- 1974-03-20 DD DD177300A patent/DD110310A5/xx unknown
- 1974-03-21 CA CA195,673A patent/CA1036966A/en not_active Expired
- 1974-03-21 AT AT234574A patent/AT324265B/en not_active IP Right Cessation
- 1974-03-21 LU LU69676A patent/LU69676A1/xx unknown
- 1974-03-21 PL PL1974169703A patent/PL88670B1/pl unknown
- 1974-03-21 ZA ZA00741842A patent/ZA741842B/en unknown
- 1974-03-21 AR AR252890A patent/AR201575A1/en active
- 1974-03-21 CH CH396474A patent/CH617719A5/en not_active IP Right Cessation
- 1974-03-21 SU SU742006550A patent/SU620218A4/en active
- 1974-03-21 DK DK157374AA patent/DK140146B/en not_active IP Right Cessation
- 1974-03-22 CS CS742101A patent/CS193502B2/en unknown
- 1974-03-22 ES ES424884A patent/ES424884A1/en not_active Expired
- 1974-03-22 BR BR2308/74A patent/BR7402308D0/en unknown
- 1974-03-22 JP JP3158974A patent/JPS5438657B2/ja not_active Expired
- 1974-03-22 SE SE7403922A patent/SE400974B/en unknown
- 1974-03-27 IL IL44510A patent/IL44510A/en unknown
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