EP0046344A2
Expired / Lapsed
EP
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Fermentation process
Assignee: Monsanto Co
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Filing: 1981-07-23
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Granted: —
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Expires: 2001-07-23
Abstract
Abstract Continuous fermentation of Alcaligenes micro-organisms capable of accumulating PHB under limitation of a nutrient required for growth, but not PHB accumulation, so that the PHB content is above 25% by weight. By means of this the carbon in the carbon and energy source, i.e. the substrate, is utilised more efficiently.
Inventors
- 👤 Lorenzo Hughes
- 👤 Kenneth Raymond Richardson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 21:16
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/62; C12P7/625; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/822; Y10S435/829
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
A fermentation process for the production of bacterial cell containing poly(β-hydroxy butyric acid), PΞB, comprising aerobically culturing a PHB-accumulating micro-organism of thr Alcligenes genus continuously in a fermentation vessel to which (a) an aqueous medium containing nutrient salts and (b) as a carbon and energy source, a water soluble compound that is assimilable by the micro-organism and which contains at least carbon and hydrogen, are continuously or intermittently supplied and continuously or intermittently removing an equivalent amount of aqueous medium containing the bacterial cells from the vessel so as to maintain the amount of aqueous medium in the vessel substantially constant, the amount of at least one of the essential requirements for growth of the micro-organism, but not for accumulation of PHB, supplied to the vessel being restricted such that the bacterial cells removed therefrom contain, an average, at least 25% by weight of PHB.
Claim 2
Dependent Claim
145 words
A fermentation process for the production of bacterial cell containing poly(β-hydroxy butyric acid), PΞB, comprising aerobically culturing a PHB-accumulating micro-organism of thr Alcligenes genus continuously in a fermentation vessel to which (a) an aqueous medium containing nutrient salts and (b) as a carbon and energy source, a water soluble compound that is assimilable by the micro-organism and which contains at least carbon and hydrogen, are continuously or intermittently supplied and continuously or intermittently removing an equivalent amount of aqueous medium containing the bacterial cells from the vessel so as to maintain the amount of aqueous medium in the vessel substantially constant, the amount of at least one of the essential requirements for growth of the micro-organism, but not for accumulation of PHB, supplied to the vessel being restricted such that the bacterial cells removed therefrom contain, an average, at least 25% by weight of PHB.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the essential requirement for growth is selected from assimilable nitrogen and phosphorus.
Claim 4
Dependent Claim
62 words
A process according to claim 2 wherein the essential requirement for growth that is restricted is nitrogen and the amount of assimilable nitrogen that is supplied to the fermentation vessel is from 8 to 15% by weight of the difference between the amount of bacterial cells removed from the fermentation vessel and the amount of PHB accumulated in said removed bacterial cells.
Claim 5
Dependent Claim
28 words
A process according to any one of claims 1 to 3 wherein the bacterial cells removed from the vessel contain from 35 to 65% by weight of PEB.
Claim 6
Dependent Claim
29 words
A process according to any one of claims 1 to 4 wherein the aqueous medium removed from the vessel contains at least 5 g per litre of bacterial cells.
Claim 7
Dependent Claim
41 words
A process according to any one of claims 1 to 5 wherein the aqueous medium removed from the vessel contains a residual amount of at least 1 g per litre of said water soluble compound forming the carbon and energy source.
Claim 8
Dependent Claim
78 words
A process according to any one of claims 1 to 6 wherein the aqueous medium containing the bacterial cells removed from the vessel is fed to a further fermentation vessel together with, as a carbon and energy source, a water soluble compound that is assimilable by the micro-organism and which contains at least carbon and hydrogen, and the micro-organism is aerobically cultured in said further fermentation vessel so as to increase the PHB content of the bacterial cells.
Claim 9
Dependent Claim
47 words
A process according to claim 7 wherein no additional quantity of said essential requirement for growth whose supply to the first fermentation vessel is restricted, over any residual quantity remaining in the aqueous medium removed from the first fermentation vessel, is supplied to said further fermentation vessel.
Claim 10
Dependent Claim
22 words
A process according to claim 7 or claim 8 wherein the culturing of the micro-organism in said further fermentation vessel is continuous.
Claim 11
Dependent Claim
40 words
A process according to any one of claims 7 to 9 wherein the culturing of the micro-organism in said further fermentation vessel is continued until the bacterial cells have a PHB content within the range 50 to 80% by weight.
References Cited (Backward Citations)
No citation records indexed.
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