HETEROLOGOUS PROTEASE EXPRESSION FOR IMPROVING ALCOHOLIC FERMENTATION
The present disclosure relates to proteases for improving alcoholic fermentation. The proteases are expressed from a recombinant host cell. The present disclosure also provides a population of recombinant host cells expressing an heterologous protease that can be used in combination with recombinant host cells expressing an heterologous glucoamylase and/or an heterologous glycerol reduction system.
1 . A first recombinant yeast host cell comprising a first genetic modification allowing the expression of a heterologous protease, wherein the heterologous protease is:
a) a polypeptide having the amino acid sequence of SEQ ID NO: 2, 6, 8, 10, 12, 14, 30, 36, 38, 40, 42, 52 or 92;
b) a variant having at least 70% identity to the polypeptide of a) and exhibiting proteolytic activity; or
c) a fragment having at least 70% identity to the polypeptide of a) or the variant of b) and exhibiting proteolytic activity.
2 .- 8 . (canceled)
9 . The first recombinant yeast host cell of claim 1 , having a second genetic modification allowing the expression of a heterologous glucoamylase.
10 . The first recombinant yeast host cell of claim 9 , wherein the heterologous glucoamylase has the amino acid sequence of SEQ ID NO: 91, is a variant of the amino acid sequence of SEQ ID NO: 91, is a fragment of the amino acid sequence of SEQ ID NO: 91, or is a fragment of the variant.
11 . The first recombinant yeast host cell of claim 1 having a third genetic modification for reducing the production of one or more native enzymes that function to produce glycerol or regulate glycerol synthesis.
12 . The first recombinant yeast host cell of claim 11 , wherein the third genetic modification is for reducing the production of one or more native enzymes that function to produce glycerol.
13 . The first recombinant yeast host cell of claim 12 , wherein the third genetic modification is for reducing or inhibiting in the expression of the gene encoding the GPD2 polypeptide.
14 . The first recombinant yeast host cell of claim 1 having a fourth genetic modification for reducing the production of one or more native enzymes that function to catabolize formate.
15 . The first recombinant yeast host cell of claim 14 , wherein the fourth genetic modification is for reducing or inhibiting the expression of the genes encoding the FDH1 polypeptide and the FDH2 polypeptide.
16 . The first recombinant yeast host cell of claim 1 , wherein the first recombinant yeast host cell is from the genus Saccharomyces.
17 . The first recombinant yeast host cell of claim 16 , wherein the first recombinant yeast host cell is from the species Saccharomyces cerevisiae.
18 .- 26 . (canceled)
27 . A process for promoting ethanolic fermentation, the process comprising fermenting a medium with the first recombinant yeast host cell defined in claim 1 .
28 . The process of claim 27 , wherein the medium comprises raw starch.
29 . The process of claim 27 , wherein the medium is derived from corn.
30 . The process of claim 27 , wherein the medium is derived from barley.
31 . The process of claim 30 , wherein the barley is malted barley.
32 . A method of producing a heterologous protease in a first recombinant yeast host cell, the method comprising culturing a first recombinant yeast host cell as defined in claim 1 under conditions allowing the expression of the heterologous protease.
33 .- 44 . (canceled)