US4574117A
Expired / Lapsed
US
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Stabilization of phenylalanine ammonia-lyase in a bioreactor using reducing agents
Assignee: Genex Corp
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Filing: 1984-06-06
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Granted: 1986-03-04
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Expires: 2004-06-06
Abstract
Abstract A method is disclosed for producing L-phenylalanine using, as a catalyst, phenylalanine ammonia-lyase (PAL). Reducing agents are added to a bioreaction mixture containing t-cinnamic acid and ammonia or soluble ammonium salts, in order to reduce the effects of oxygen on catalyst life. The reducing agents of the invention include any substance that lowers the overall electrochemical potential of the solution, or which has a tendency to donate electrons to an oxidizing agent.
Inventors
- 👤 Patricia J. Vollmer
- 👤 Jeffrey J. Schruben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:42
CPC Classifications
C; C12; C12N; C12N9/00; C12N9/88; C12N9/96; C12P; C12P13/00; C12P13/04; C12P13/22; C12P13/222
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
71 words
A method for producing L-phenylalanine which comprises: (a) cultivating a PAL-producing microorganism under aerobic, growth-promoting conditions; (b) inducing the cells produced in step (a) to make PAL under PAL-producing conditions; (c) forming a bioreaction mixture by combining, under L-phenylalanine-producing conditions, the PAL produced by step (b) with t-cinnamic acid and ammonium ions in the presence of one or more reducing agents, to produce L-phenylalanine; and (d) recovering the L-phenylalanine so produced.
Claim 2
Independent Claim
71 words
A method for producing L-phenylalanine which comprises: (a) cultivating a PAL-producing microorganism under aerobic, growth-promoting conditions; (b) inducing the cells produced in step (a) to make PAL under PAL-producing conditions; (c) forming a bioreaction mixture by combining, under L-phenylalanine-producing conditions, the PAL produced by step (b) with t-cinnamic acid and ammonium ions in the presence of one or more reducing agents, to produce L-phenylalanine; and (d) recovering the L-phenylalanine so produced.
Claim 3
Dependent Claim
50 words
The method of claim 1, wherein the reducing agents are selected from the group consisting of: hydrogen sulfide, thioglycolic acid, thiosulfuric acid, nitrous acid, sulfurous acid, ammonium and metal salts of the above, dithiothreitol, ethylmercaptan, ethylenemercaptan, methylmercaptan, 2-mercaptoethanol, hydrogen, nitrous oxide, iron (II) compounds, manganese (II) compounds, sulfur and zinc.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein the reducing agent or agents are present in amounts of from about 1.0 to about 20 millimoles per liter of bioreaction solution.
Claim 5
Dependent Claim
48 words
The method of claim 3, wherein the bioreaction mixture contains initially from about 5.0 to 30.0 grams per liter of t-cinnamic acid, from about 0.1 to about 9.0 moles per liter of ammonia, and from about 50 to about 200 grams per liter of a soluble ammonium salt.
Claim 6
Dependent Claim
34 words
The method of claim 4, wherein the bioreaction is carried out at a pH of from about 9.0 to about 11.0 and at a temperature of from about 25° C. to about 40° C.
Claim 7
Dependent Claim
28 words
The method of claim 5, wherein the reducing agent is 2-mercaptoethanol or thioglycolic acid, and is in concentrations of from about 4 to about 10 millimoles per liter.
References Cited (Backward Citations)
GB1489468A
Cited
US4277562A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-03 | 1989-09-02 | 1990-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-03 | 1993-09-02 | 1994-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-03 | 1997-09-02 | 1998-03-04 | $7700.00 | Window Closed / Lapsed |