Yeast strain with glucose and xylose co-utilization capacity

Patent metadata

Field	Value
Publication number	US-11319556-B2
Application number	US-201916551335-A
Country	US
Kind code	B2
Filing date	Aug 26, 2019
Priority date	Nov 8, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

The present specification relates to a transformed yeast strain capable of simultaneously utilizing xylose and glucose as carbon sources, a preparation method thereof and a biofuel production method using the same. The transformed yeast strain transforms a wild-type yeast strain incapable of using xylose as a carbon source and simultaneously convert glucose and xylose, thereby enabling high yield production of a biofuel. The economics and sustainability of the biofuel and biomaterial production processes can be highly enhanced by providing a strain which can easily be converted to a strain capable of producing a biofuel/material in a high yield through an additional modification.

First claim

What is claimed is:

1. A transformed yeast strain of Saccharomyces cerevisiae , comprising
at least one of a mutant of SEQ NO: 1 (PMR1) and a mutant of SEQ ID NO: 3 (ASC1); and
a gene encoding a xylose isomerase; and at least one of a gene encoding a xylulokinase and a gene encoding a transaldolase,
wherein the mutant of SEQ ID NO: 1 (PMR1) is SEQ ID NO: 2 (PMR1 G681A ); and
wherein the mutant of SEQ ID NO: 3 (ASC1) is SEQ ID NO: 4 (ASC1 Q237* );
wherein the gene encoding the xylose isomerase is SEQ ID NO: 5 (xylA3*), SEQ ID NO: 6 (xylA), SEQ ID NO: 7 (xylA), or SEQ ID NO: 8 (xylA);
wherein the gene encoding the xylulokinase is SEQ ID NO: 9 (XKS1) or SEQ ID NO: 10 (xyl3); and
wherein the gene encoding the transaldolase is SEQ ID NO: 11 (TAL1) or SEQ ID NO: 12 (tal1).

2. The transformed yeast strain of claim 1 , wherein at least one of an aldose reductase-encoding gene and a phosphatase-encoding gene is deleted.

3. The transformed yeast strain of claim 1 , wherein a parent strain of the transformed Saccharomyces cerevisiae is a wild type Saccharomyces cerevisiae yeast strain.

4. The transformed yeast strain of claim 3 , wherein the wild type Saccharomyces cerevisiae yeast strain is ATCC 201388.

5. The transformed yeast strain of claim 2 ,
wherein the gene encoding the aldose reductase is SEQ ID NO: 13 (GRE3); and/or
wherein the gene encoding the phosphatase is SEQ ID NO: 14 (PHO13).

6. The transformed yeast strain of claim 1 , wherein the transformed yeast strain is Accession No.KCTC13614BP.

7. The transformed yeast strain of claim 1 , wherein the transformed yeast strain simultaneously ferments glucose and xylose to convert into ethanol.

8. The transformed yeast strain of claim 1 , further comprising genes constituting a butanol biosynthetic pathway comprising of SEQ ID NO: 17 (β-hydroxybutyryl-CoA dehydrogenase, Hbd), SEQ ID NO: 18 (3-hydroxybutyryl-CoA dehydratase, Crt), SEQ ID NO: 19 (butanol dehydrogenase, BdhB), SEQ ID NO: 20 (acetoacetyl-CoA thiolase, Erg10), SEQ ID NO: 21 (enoyl thioester reductase, Etrl), and SEQ ID NO: 22 (butyraldehyde dehydrogenase, EutE).

9. The transformed yeast strain of claim 8 , wherein the butanol biosynthetic pathway-constituting genes are introduced in the form of being inserted in a genomic DNA or in the form of a plasmid.

10. The transformed yeast strain of claim 9 , wherein a plasmid of SEQ ID NO: 23, a plasmid of SEQ ID NO: 24 and a plasmid of SEQ ID NO: 25 are introduced.

11. A method for preparing the transformed yeast strain according to claim 1 , comprising:
inserting the gene encoding xylose isomerase; and at least one of the gene encoding xylulokinase and the gene encoding transaldolase; and
performing at least one of a mutation of SEQ ID NO: 1 (PMR1) and a mutation of SEQ ID NO: 3 (ASC1),
while having Saccharomyces cerevisiae as a parent strain.

12. The method of claim 11 , further comprising deleting at least one of an aldose reductase-encoding gene and a phosphatase-encoding gene.

13. The method of claim 11 , wherein the mutation of PMR1 or ASC1 comprises adaptive evolution by subculturing the strain in a minimal medium comprising xylose as a sole carbon source.

14. The method of claim 11 , wherein the insertion of gene is carried out using CRISPR/Cas9.

15. The method of claim 11 , further comprising introducing genes constituting a butanol biosynthetic pathway comprising β-hydroxybutyryl-CoA dehydrogenase (Hbd), 3-hydroxybutyryl-CoA dehydratase (Crt), butanol dehydrogenase (BdhB), acetoacetyl-CoA thiolase (Erg10), enoyl thioester reductase (Etr1), and butyraldehyde dehydrogenase (EutE).

16. The method of claim 15 , wherein the introduction of the butanol biosynthetic pathway-constituting genes comprises introducing the butanol biosynthetic pathway-constituting genes in the form of a plasmid or in the form of being inserted into a genomic DNA.

17. The method of claim 16 , wherein the introduction of the butanol biosynthetic pathway-constituting genes comprises introducing a plasmid of SEQ ID NO: 23, a plasmid of SEQ ID NO: 24 and a plasmid of SEQ ID NO: 25.

18. A method for producing a biofuel and biomaterial, comprising fermenting the transformed yeast strain according to claim 1 by culturing the transformed yeast strain in a medium comprising xylose as a sole carbon source or a medium comprising glucose and xylose as carbon sources.

19. The method of claim 18 , wherein the biofuel includes ethanol.

Assignees

• Korea Inst Sci & Tech

Inventors

• Lee Sun Mi
• Tran Phuong Nguyen Hoang
• Um Youngsoon
• Gong Gyeongtaek
• Ko Ja Kyong
• Lee Yeonjung

Classifications

• C12Y202/01002

  Transaldolase (2.2.1.2) · CPC title

• C12N9/1205

  Phosphotransferases with an alcohol group as acceptor (2.7.1), e.g. protein kinases · CPC title

• C12Y102/01057 Primary

  Butanal dehydrogenase (1.2.1.57) · CPC title

• C12N15/81

  for yeasts · CPC title

• C12N9/22

  Ribonucleases {[RNase]; Deoxyribonucleases [DNase]} · CPC title