US4511656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct fermentation of D-xylose to ethanol by a xylose-fermenting yeast mutant
Assignee: Purdue Research Foundation
•
Filing: 1982-05-11
•
Granted: 1985-04-16
•
Expires: 2002-05-11
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. In addition, a process for producing yeast mutants capable of utilizing D-xylose to ethanol in high yields is described. 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
2026-11-05 22:55
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; Y10S435/94; Y10S435/942
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
92 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nurients and D-xylose with a yeast mutant having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 50%, permitting the inoculated medium to ferment for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 50% and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 2
Dependent Claim
92 words
A process for the direct fermentation of D-xylose to ethanol which comprises inoculating a medium comprising growth nurients and D-xylose with a yeast mutant having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 50%, permitting the inoculated medium to ferment for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 50% and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the conversion of D-xylose to ethanol is at least 80%.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the parent yeast strain is Candida sp.
Claim 5
Dependent Claim
15 words
A process according to claim 1 wherein the yeast mutant is Candida sp. XF 217.
Claim 6
Dependent Claim
13 words
A process according to claim 1 wherein the parent strain is Saccharomyces cerevisiae.
Claim 7
Dependent Claim
15 words
A process according to claim 1 wherein the yeast mutant is Saccharomyces cerevisiae SCXF 138.
Claim 8
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 9
Dependent Claim
17 words
A process according to claim 7 wherein said initial concentration ranges from about 5 to 30 percent.
Claim 10
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 11
Dependent Claim
13 words
A process according to claim 9 wherein said temperature is about 30° C.
Claim 12
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 13
Dependent Claim
12 words
A process according to claim 11 wherein said pH is about 6.
Claim 14
Dependent Claim
14 words
A process according to claim 1 wherein fermentation is carried out under aerobic conditions.
Claim 15
Dependent Claim
14 words
A process according to claim 1 wherein fermentation is carried out under anaerobic conditions.
Claim 16
Dependent Claim
14 words
A process according to claim 1 wherein the D-xylose is contained in hemicellulose hydrolyzate.
Claim 17
Dependent Claim
14 words
A process according to claim 1 wherein said medium also contains cellulose hydrolyzate material.
Claim 18
Dependent Claim
125 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 having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 50%, fermenting the inoculated 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 a 50% conversion of the D-xylose to ethanol, and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 19
Dependent Claim
125 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 having an ability to ferment D-xylose to ethanol with a bioconversion yield of at least 50%, fermenting the inoculated 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 a 50% conversion of the D-xylose to ethanol, and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 20
Dependent Claim
17 words
A process according to claim 17 wherein the temperature is about 30° C. and pH about 6.
Claim 21
Dependent Claim
97 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 having an ability to ferment D-glucose and D-xylose to ethanol with a bioconversion yield of at least 50%, fermenting the inoculated medium for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 50% and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 22
Dependent Claim
97 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 having an ability to ferment D-glucose and D-xylose to ethanol with a bioconversion yield of at least 50%, fermenting the inoculated medium for a period of time sufficient to achieve a conversion of D-xylose to ethanol of at least 50% and recovering the ethanol so produced as product, said mutant being obtained from a parent yeast strain selected from the group consisting of Candida sp. and Saccharomyces cerevisiae.
Claim 23
Dependent Claim
18 words
A process according to claim 19 wherein the D-glucose and D-xylose are obtained from cellulose and hemicellulose hydrolyzate.
Claim 24
Dependent Claim
16 words
A process according to claim 17 or 19 wherein said yeast mutant is Candida sp. XF217.
Claim 25
Dependent Claim
12 words
A culture consisting essentially of a mutant strain Candida sp. XF 217.
Claim 26
Dependent Claim
12 words
A culture consisting essentially of a mutant strain Candida sp. XF 217.
Claim 27
Dependent Claim
12 words
A culture consisting essentially of a mutant strain Saccharomyces cerevisiae SCXF 138.
Claim 28
Dependent Claim
12 words
A culture consisting essentially of a mutant strain Saccharomyces cerevisiae SCXF 138.
References Cited (Backward Citations)
US1857429A
Cited
US2481263A
Cited
US3887434A
Cited
US4288550A
Cited
US4359534A
Cited
US4368268A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-15 | 1988-10-15 | 1989-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-15 | 1992-10-15 | 1993-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-15 | 1996-10-15 | 1997-04-16 | $7700.00 | Window Closed / Lapsed |