Compositions and methods for 3-hydroxypropionic acid production
The present application discloses genetically modified yeast cells comprising an active 3-HP fermentation pathway, and the use of these cells to produce 3-HP.
1 . A genetically modified yeast cell comprising an active 3-HP fermentation pathway, wherein the cell is capable of growing at a pH of less than 4 in media containing 75 g/L or greater 3-HP.
2 . The genetically modified yeast cell of claim 1 , wherein the cell is capable of growing at a pH of less than 4 in media containing 100 g/L or greater 3-HP.
3 . The genetically modified yeast cell of claim 1 , wherein the cell is a 3-HP-resistant yeast cell.
4 . The genetically modified yeast cell of claim 1 , wherein the cell is capable of growing at a pH of less than 4 in media containing 100 g/L or greater 3-HP.
5 . The genetically modified yeast cell of claim 1 , comprising an exogenous PYC gene.
6 . The genetically modified yeast cell of claim 1 , wherein the cell has undergone mutation and/or selection, such that the mutated and/or selected cell possess a higher degree of resistance to 3-HP than a wild-type cell of the same species.
7 . The genetically modified yeast cell of claim 6 , wherein the cell has undergone mutation and/or selection before being genetically modified with the one or more exogenous 3-HP pathway genes.
8 . The genetically modified yeast cell of claim 6 , wherein the cell has undergone selection in the presence of lactic acid or 3-HP.
9 . The genetically modified yeast cell of claim 8 , wherein the selection is chemostat selection.
10 . The genetically modified yeast cell of claim 1 , wherein said cell is Crabtree-negative.
11 . The genetically modified yeast cell of claim 1 , wherein the cell belongs to a genus selected from Issatchenkia, Candida, Kluyveromyces, Pichia, Schizosaccharomyces, Torulaspora, Zygosaccharomyces , and Saccharomyces.
12 . The genetically modified yeast cell of claim 11 , wherein the cell belongs to a clade selected from the I. orientalis/P. fermentans clade and the Saccharomyces clade.
13 . The genetically modified yeast cell of claim 11 , wherein the cell is selected from I. orientalis, C. lambica , and S. bulderi.
14 . The genetically modified yeast cell of claim 11 , wherein the cell an I. orientalis CNB1 yeast cell.
15 . The genetically modified yeast cell of claim 1 , wherein the cell is unable to ferment pentose sugars.
16 . A method of producing 3-HP comprising:
(i) culturing the genetically modified yeast cell of claim 1 in the presence of medium comprising at least one carbon source; and
(ii) isolating 3-HP from the culture.
17 . The method of claim 16 , wherein said carbon source is selected from glucose, xylose, arabinose, sucrose, fructose, cellulose, glucose oligomers, and glycerol.
18 . The method of claim 16 , wherein the medium is at a pH of less than 5.
19 . The method of claim 16 , wherein the modified yeast cell is an I. orientalis CNB1 yeast cell.
20 . The method of claim 16 , wherein the modified yeast cell is unable to ferment pentose sugars.