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US4368268A
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US
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Direct fermentation of D-xylose to ethanol by a xylose-fermenting yeast mutant
Assignee: Purdue Research Foundation
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Filing: 1981-05-15
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Granted: 1983-01-11
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Expires: 2001-05-15
Abstract
Abstract A process for obtaining ethanol directly from D-xylose through fermentation of D-xylose by xylose-fermenting yeast mutants. The process provides for obtaining ethanol from hemicellulose hydrolyzates through yeast fermentation of D-xylose to ethanol. Furthermore, the process also provides for obtaining ethanol from a mixture of cellulose and hemicellulose hydrolyzates through yeast fermentation of D-glucose and D-xylose directly and simultaneously to ethanol.
Inventors
- 👤 Cheng-Shung Gong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:54
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/02; C12P7/04; C12P7/06; C12P7/08; C12P7/10; C12N; C12N1/00; C12N1/14; C12N1/16; C12N1/165; C12N1/18; C12N1/185; C12R; C12R2001/00; C12R2001/645; C12R2001/72; C12R2001/85; C12R2001/865; Y; Y02; Y02E; Y02E50/00; Y02E50/10; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/911; Y10S435/921
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
77 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nutrients and D-xylose with a yeast mutant of the strain Candida sp. having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 80%, permitting the inoculated medium to ferment for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 80% and recovering the ethanol so produced as product.
Claim 2
Dependent Claim
77 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nutrients and D-xylose with a yeast mutant of the strain Candida sp. having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 80%, permitting the inoculated medium to ferment for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 80% and recovering the ethanol so produced as product.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the yeast mutant is Candida sp. XF-217.
Claim 4
Dependent Claim
26 words
A process according to claim 1 wherein the initial concentration of D-xylose in said medium ranges from 1 to about 40 percent on a weight/volume basis.
Claim 5
Dependent Claim
17 words
A process according to claim 3 wherein said initial concentration ranges from about 5 to 30 percent.
Claim 6
Dependent Claim
22 words
A process according to claim 1 wherein fermentation is carried out at a temperature ranging from about 22° to about 40° C.
Claim 7
Dependent Claim
13 words
A process according to claim 5 wherein said temperature is about 30° C.
Claim 8
Dependent Claim
21 words
A process according to claim 1 wherein fermentation is carried out at a pH ranging from about 4 to about 8.
Claim 9
Dependent Claim
12 words
A process according to claim 7 wherein said pH is about 6.
Claim 10
Dependent Claim
14 words
A process according to claim 1 wherein fermentation is carried out under aerobic conditions.
Claim 11
Dependent Claim
14 words
A process according to claim 1 wherein fermentation is carried out under anaerobic conditions.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein the D-xylose is contained in hemicellulose hydrolyzate.
Claim 13
Dependent Claim
14 words
A process according to claim 1 wherein said medium also contains cellulose hydrolyzate material.
Claim 14
Dependent Claim
110 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nutrients and D-xylose in an amount of from 1 to about 40% by weight/volume of said medium with a yeast mutant of the strain Candida sp. having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 80%, fermenting the innoculated medium at a temperature ranging from about 22° to about 40° C. and a pH ranging from about 4 to about 8 for a period of time sufficient to achieve at least an 80% conversion of the D-xylose to ethanol, and recovering the ethanol so produced as product.
Claim 15
Dependent Claim
110 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nutrients and D-xylose in an amount of from 1 to about 40% by weight/volume of said medium with a yeast mutant of the strain Candida sp. having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 80%, fermenting the innoculated medium at a temperature ranging from about 22° to about 40° C. and a pH ranging from about 4 to about 8 for a period of time sufficient to achieve at least an 80% conversion of the D-xylose to ethanol, and recovering the ethanol so produced as product.
Claim 16
Dependent Claim
17 words
A process according to claim 13 wherein the temperature is about 30° C. and pH about 6.
Claim 17
Dependent Claim
82 words
A process for the production of ethanol directly and simultaneously from D-glucose and D-xylose which comprises inoculating a medium comprising growth nutrients, D-glucose and D-xylose with a yeast mutant of the strain Candida sp. having an ability to ferment D-glucose and D-xylose to ethanol with a bioconversion yield of at least 80%, fermenting the innoculated medium for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 80% and recovering the ethanol so produced as product.
Claim 18
Dependent Claim
82 words
A process for the production of ethanol directly and simultaneously from D-glucose and D-xylose which comprises inoculating a medium comprising growth nutrients, D-glucose and D-xylose with a yeast mutant of the strain Candida sp. having an ability to ferment D-glucose and D-xylose to ethanol with a bioconversion yield of at least 80%, fermenting the innoculated medium for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 80% and recovering the ethanol so produced as product.
Claim 19
Dependent Claim
18 words
A process according to claim 15 wherein the D-glucose and D-xylose are obtained from cellulose and hemicellulose hydrolyzate.
Claim 20
Dependent Claim
46 words
A process according to claim 1, 13 or 15 wherein said yeast mutant is obtained by purifying the parent yeast strain by single colony isolation, exposing the isolated single colony to irradiation to produce a mutated strain, and isolating a single colony of the mutated strain.
Claim 21
Dependent Claim
18 words
A process according to claim 13, 15 or 16 wherein said yeast mutant is Candida sp. XF 217.
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) | 1986-01-10 | 1986-07-12 | 1987-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-10 | 1990-07-12 | 1991-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-10 | 1994-07-12 | 1995-01-11 | $7700.00 | Window Closed / Lapsed |