Acetate consuming yeast cell
The present invention relates to a yeast cell that is genetically modified comprising: a) a disruption of one or more aldehyde dehydrogenase (E.C:1.2.1.4) native to the yeast; b) one or more nucleotide sequence encoding a heterologous NAD+-dependent acetylating acetaldehyde dehydrogenase (E.C. 1.2.1.10); c) one or more nucleotide sequence encoding a homologous or heterologous acetyl-CoA synthetase (E.C. 6.2.1.1); and d) a modification that leads to reduction of glycerol 3-phosphate phosphohydrolase (E.C. 3.1.3.21) and/or glycerol 3-phosphate dehydrogenase (E.C. 1.1.1.8 or E.C. 1.1.5.3) activity, native to the yeast.
1. A yeast cell that is genetically modified comprising:
a) a disruption of one or more aldehyde dehydrogenase (E.C:1.2.1.4) native to the yeast;
b) one or more nucleotide sequence encoding a heterologous NAD+-dependent acetylating acetaldehyde dehydrogenase (E.C. 1.2.1.10);
c) one or more nucleotide sequence encoding a homologous or heterologous acetyl-CoA synthetase (E.C. 6.2.1.1); and
d) a modification that leads to reduction of glycerol 3-phosphate phosphohydrolase (E.C. 3.1.3.21) and/or glycerol 3-phosphate dehydrogenase (E.C. 1.1.1.8 or E.C. 1.1.5.3) activity, native to the yeast.
2. The yeast cell according to claim 1 , wherein the one or more aldehyde dehydrogenase (E.C:1.2.1.4) native to the yeast in a) is an acetaldehyde dehydrogenase-6 (ALD6).
3. The yeast cell according to claim 1 , wherein the yeast cell comprises e) one or more nucleotide sequence encoding a heterologous xylose isomerase (E.C. 5.3.1.5).
4. The yeast cell according to claim 1 , wherein the yeast cell comprises a disruption of one or more of the genes gpp1, gpp2, gpd1 and gpd2 native to the yeast.
5. The yeast cell according to claim 1 , wherein the yeast cell comprises further:
f) one or more nucleotide sequence encoding a heterologous glycerol dehydrogenase (E.C. 1.1.1.6); and
g) one or more nucleotide sequence encoding a homologous or heterologous dihydroxyacetone kinase (E.C. 2.7.1.28 or E.C. 2.7.1.29).
6. The yeast cell according to claim 1 , wherein the yeast cell is a pentose and glucose fermenting yeast cell that is capable of anaerobic simultaneous pentose and glucose consumption.
7. A process for the fermentation of a yeast cell according to claim 1 , wherein the fermentation time for substantially complete fermentation of acetate, pentose and hexose is reduced relative to the corresponding fermentation of wild-type yeast.
8. The process according to claim 7 , wherein the fermentation time is reduced 40% or more.
9. The process according to claim 6 , wherein pentose and glucose are co-fermented.
10. The process according to any of claim 7 , wherein the overall ethanol production rate is at least about 20%, at least about 50% or about 100% higher than that of a process with the corresponding wild-type yeast.
11. The process according to claim 7 , wherein a hydrolysate of lignocellulosic material is fermented.
12. The process according to claim 11 , wherein the hydrolysate is an enzymatic hydrolysate of lignocellulosic material.
13. The process according to claim 11 , wherein the hydrolysate comprises acetate.
14. The process according to claim 13 , wherein the acetate comprising hydrolysate has an acetate concentration of 5% (w/w) or more.