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US4245049A
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Preparation of 2-keto-L-gulonic acid
Assignee: Pfizer Inc
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Filing: 1980-01-21
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Granted: 1981-01-13
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Expires: 2000-01-21
Abstract
Abstract 2-Keto-L-gulonic acid, an ascorbic acid intermediate, is prepared by cultivating a microorganism of the genus Citrobacter in an aqueous nutrient medium in the presence of 2,5-diketo-D-gluconic acid.
Inventors
- 👤 Donald A. Kita
- 👤 Karlene E. Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:42
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/40; C12P7/58; C12P7/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
36 words
A process for producing 2-keto-L-gulonic acid or a salt thereof which comprises cultivating a 2-keto-L-gulonic acid-producing microorganism of the genus Citrobacter in an aqueous nutrient medium in the presence of 2,5-diketo-D-gluconic acid or a salt thereof.
Claim 2
Dependent Claim
36 words
A process for producing 2-keto-L-gulonic acid or a salt thereof which comprises cultivating a 2-keto-L-gulonic acid-producing microorganism of the genus Citrobacter in an aqueous nutrient medium in the presence of 2,5-diketo-D-gluconic acid or a salt thereof.
Claim 3
Dependent Claim
18 words
A process according to claim 1 wherein the microorganism is a strain of Citrobacter freundii or Citrobacter diversus.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the 2,5-diketo-D-gluconic acid salt is sodium 2,5-diketo-D-gluconate.
Claim 5
Dependent Claim
14 words
A process according to claim 1 wherein the 2,5-diketo-D-gluconic acid salt is calcium 2,5-diketo-D-gluconate.
Claim 6
Dependent Claim
21 words
A process according to claim 1 wherein the cultivation is conducted at a pH of from about 5.5 to about 7.5.
Claim 7
Dependent Claim
23 words
A process according to claim 1 wherein the cultivation is conducted at a temperature of from about 25° C. to about 35° C.
Claim 8
Dependent Claim
15 words
A process according to claim 2 wherein said strain is Citrobacter freundii ATCC No. 6750.
Claim 9
Dependent Claim
15 words
A process according to claim 2 wherein said strain is Citrobacter freundii ATCC No. 10787.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |