Patent US4324907A successfully refreshed from Google Patents.
US4324907A
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Extraction process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1980-02-22
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Granted: 1982-04-13
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Expires: 2000-02-22
Abstract
Abstract Poly(β-hydroxybutyric acid) is separated from bacterial cells by drying a finely divided stream or spray of an aqueous suspension of the cells with a gas heated to above 100° C. and then extracting the PHB, preferably after a lipid extraction step with a solvent such as a partially halogenated hydrocarbon such as 1,2-dichloroethane, chloroform or dichlorom
Inventors
- 👤 Peter J. Senior
- 👤 Leonard F. Wright
- 👤 Barry Alderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:18
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/88; C08G63/89; C12; C12P; C12P7/00; C12P7/62; C12P7/625
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
98 words
A process for the extraction of poly(β-hydroxy butyric acid) (PHB) from an aqueous suspension of PHB-containing bacterial cells comprising: introducing an aqueous suspension of PHB-containing bacterial cells in finely divided form into a current of gas heated to a temperature of at least 100° C. to evaporate the water from the suspension, collecting the resultant dried bacterial cells, extracting the PHB therefrom by contact with an extraction solvent which is a liquid that is a solvent for the PHB in the bacterial cells, and separating the extraction solvent from the PHB dissolved therein from the bacterial cell residue.
Claim 2
Dependent Claim
98 words
A process for the extraction of poly(β-hydroxy butyric acid) (PHB) from an aqueous suspension of PHB-containing bacterial cells comprising: introducing an aqueous suspension of PHB-containing bacterial cells in finely divided form into a current of gas heated to a temperature of at least 100° C. to evaporate the water from the suspension, collecting the resultant dried bacterial cells, extracting the PHB therefrom by contact with an extraction solvent which is a liquid that is a solvent for the PHB in the bacterial cells, and separating the extraction solvent from the PHB dissolved therein from the bacterial cell residue.
Claim 3
Dependent Claim
44 words
A process according to claim 1 wherein, prior to contact of the dried cells with the extraction solvent, the dried cells are contacted with a liquid in which PHB is not soluble but in which lipids and/or pigment in the bacterial cells is soluble.
Claim 4
Dependent Claim
20 words
A process according to claim 2 in which the liquid in which PHB is not soluble is acetone or methanol.
Claim 5
Dependent Claim
22 words
A process according to claim 1 in which the gas is heated to a temperature in the range 100° to 500° C.
Claim 6
Dependent Claim
22 words
A process according to claim 4 in which the gas is heated to a temperature in the range 120° to 250° C.
Claim 7
Dependent Claim
16 words
A process according to claim 1 in which the extraction solvent is a partially halogenated hydrocarbon.
Claim 8
Dependent Claim
16 words
A process according to claim 6 in which the extraction solvent is 1,2-dichloroethane, dichloromethane, or chloroform.
Claim 9
Dependent Claim
23 words
A process according to claim 1 in which the dried cells are contacted with the extraction solvent at a temperature above 40° C.
Claim 10
Dependent Claim
22 words
A process according to claim 1 in which the weight of extraction solvent is 10 to 100 times the cell dry weight.
Claim 11
Dependent Claim
45 words
A process according to claim 1 in which the extraction solvent containing the dissolved PHB is separated from the bacterial cell residue and then added to a liquid in which PHB is insoluble and with which the extraction solvent is miscible to precipitate the PHB.
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) | 1985-04-12 | 1985-10-12 | 1986-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-12 | 1989-10-12 | 1990-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-12 | 1993-10-12 | 1994-04-13 | $7700.00 | Window Closed / Lapsed |