RECOMBINANT YEAST HOST CELLS EXPRESSING CELL-ASSOCIATED HETEROLOGOUS PROTEINS

1 . A process for making a cell-associated heterologous protein from a recombinant yeast host cell, the process comprising:

a) propagating the recombinant yeast host cell in a medium placed in a vessel according to a baker's yeast production method so as to allow expression of the cell-associated heterologous protein, wherein the recombinant yeast host cell has an heterologous nucleic acid molecule encoding the cell-associated heterologous protein and the heterologous nucleic acid molecule is operatively associated with an heterologous promoter allowing expression of the heterologous nucleic acid molecule during propagation.

2 . The process of claim 1 , wherein the baker's yeast production method is a continuous method or a fed-batch method.

3 . (canceled)

4 . The process of claim 1 , wherein a specific growth rate of the recombinant yeast host cell during the step of propagating is 0.25 h −1 or less.

5 . The process of claim 1 further comprising controlling an aeration rate of the vessel to at least about 0.5 or at least about 0.1 air volume/vessel volume/minute.

6 . (canceled)

7 . The process of claim 1 , wherein the medium comprises a carbohydrate source, a nitrogen source and a phosphorous source.

8 . The process of claim 7 , wherein:

the carbohydrate source is derived from molasses, corn, glycerol and/or a lignocellulosic biomass;

the nitrogen source is ammonia; and/or

the phosphorous source is phosphoric acid;

the medium further comprises one or more micronutrients; and/or

the medium comprises molasses.

9 .- 11 . (canceled)

12 . The process of claim 5 further comprising controlling addition of a carbohydrate source to the medium so as to limit a growth rate of the recombinant yeast host cell.

13 . The process of claim 12 comprising maintaining the concentration of the carbohydrate source at 0.1 weight percentage or less with respect to the total volume of the medium.

14 . The process of claim 13 , wherein the concentration of the carbohydrate source is maintained at 0.0001 weight percentage or less with respect to the total volume of the medium.

15 . The process of claim 5 further comprising adding a nitrogen source and/or a phosphorous source to match a growth rate of the recombinant yeast host cell.

16 . The process of claim 1 further comprising controlling pH of the medium to between about 4.0 and 5.0.

17 . The process of claim 16 comprising controlling the pH of the medium at about 4.5.

18 . The process of claim 1 further comprising controlling temperature of the medium to between about 20° C. to about 40° C. or between about 30° C. to about 35° C.

19 . (canceled)

20 . The process of claim 1 , wherein, after the step of propagating, the recombinant yeast host cell is present at a concentration of at least 0.25 weight % of total volume of the medium.

21 . The process of claim 20 , wherein, after the propagation step, the concentration of the recombinant yeast host cell is of at least 1 weight % of the total volume of the medium.

22 .- 60 . (canceled)

61 . The process of claim 1 , wherein the recombinant yeast host cell is from genus Saccharomyces sp or from species Saccharomyces cerevisiae.

62 . (canceled)

63 . The process of claim 1 for making a yeast composition, the process further comprising:

b) obtaining a propagated yeast host cell by said step of propagating and formulating the propagated yeast host cell into the yeast composition.

64 . The process of claim 63 , wherein the yeast composition is a cream yeast.

65 .- 67 . (canceled)

68 . The process of claim 1 for making a yeast product, the process further comprising:

b) obtaining a propagated yeast host cell by said step of propagating and lysing the propagated yeast host cell to obtain a lysed recombinant yeast host cell;

c) optionally drying the lysed recombinant yeast host cell to obtain a dried recombinant yeast host cell; and

d) formulating the lysed recombinant yeast host cell or the dried recombinant yeast host cell into the yeast product.

69 . The process of claim 68 , wherein step b) comprises submitting the propagated recombinant yeast host cell to autolysis to obtain the lysed recombinant yeast host cell.

70 . The process of claim of claim 69 , wherein step c) is conducted directly after step b) to provide an autolysate as the yeast product.

71 . The process of claim 69 , wherein the lysed recombinant yeast host cell comprises a soluble fraction and an insoluble fraction and the process further comprises, after step b), separating the soluble fraction from the insoluble fraction.

72 . The process of claim 71 comprising:

filtering the lysed recombinant host cell to separate the soluble fraction from the insoluble fraction;

submitting the insoluble fraction to step d) to provide yeast cell walls as the yeast product;

submitting the soluble fraction to step d) to provide a yeast extract as the yeast product;

removing components having a molecular weight equal to or less than about 10 kDa from the soluble fraction to provide a retentate; and/or

submitting the retentate to step d) to provide a dry retentate as the yeast product.

73 .- 76 . (canceled)

77 . The process of claim 63 , wherein the cell-associated heterologous protein is a heterologous enzyme.

78 . The process of claim 68 further comprising:

e) substantially purifying the heterologous protein from the lysed recombinant yeast host cell to provide a purified heterologous protein as the yeast product.

79 .- 81 . (canceled)

82 . The process of claim 68 , wherein the cell-associated heterologous protein is a heterologous enzyme.