Process of extracting oil from thin stillage
A process of recovering oil, comprising (a) converting a starch-containing material into dextrins with an alpha-amylase; (b) saccharifying the dextrins using a carbohydrate source generating enzyme to form a sugar; (c) fermenting the sugar in a fermentation medium into a fermentation product using a fermenting organism; (d) recovering the fermentation product to form a whole stillage; (e) separating the whole stillage into thin stillage and wet cake; (e′) optionally concentrating the thin stillage into syrup; (f) recovering oil from the thin stillage and/or optionally the syrup, wherein a protease and a phospholipase are present and/or added during steps (a) to (c). Use of a protease and a phospholipase for increasing oil recovery yields from thin stillage and/or syrup in a fermentation product production process.
1. A process of recovering oil, comprising
(a) converting a starch-containing material into dextrins with an alpha-amylase;
(b) saccharifying the dextrins using a carbohydrate source generating enzyme to form a sugar;
(c) fermenting the sugar in a fermentation medium into a fermentation product using a fermenting organism;
(d) recovering the fermentation product to form a whole stillage;
(e) separating the whole stillage into thin stillage and wet cake;
(e′) optionally concentrating the thin stillage into syrup;
(f) recovering oil from the thin stillage and/or optionally the syrup, wherein a protease and a phospholipase are present and/or added during steps (a) to (c), wherein the protease present and/or added in steps (a) to (c) is:
(i) a protease having the amino acid sequence set out in SEQ ID NO: 14 herein, or a protease which has at least 90% identity to SEQ ID NO: 14 having a protease activity; or
(ii) a protease having the amino acid sequence set out in SEQ ID NO: 3 herein, or a protease which has at least 90% identity to SEQ ID NO: 3 having a protease activity.
2. The process of claim 1 , wherein the protease and the phospholipase are present and/or added during steps (b) and/or (c).
3. The process of claim 1 wherein the phospholipase present and/or added in steps (a) to (c) is a phospholipase C.
4. The process of claim 1 , wherein the phospholipase, present and/or added in steps (a) to (c) has the amino acid sequence of SEQ ID NO: 15 herein; SEQ ID NO: 16 herein; or SEQ ID NO: 17 herein, preferably where the phospholipase has the amino acid sequence of SEQ ID NO: 16 herein.
5. The process of claim 1 , wherein the phospholipase present and/or added in steps (a) to (c) (i) the phospholipase shown in SEQ ID NO: 15 herein or one having a sequence identity thereto of at least 90% having a phospholipase activity; or (ii) the phospholipase shown in SEC) ID NO: 16 herein or one having a sequence identity thereto of at least 90% having a phospholipase activity; or (iii) the phospholipase shown in SEC) ID NO: 17 herein or one having a sequence identity thereto of at least 90% having a phospholipase activity.
6. The process of claim 1 , wherein the protease and the phospholipase are added sequentially or simultaneously.
7. The process of claim 1 , wherein the step (a) is performed at a temperature above the initial gelatinization temperature.
8. The process of claim 1 , wherein the temperature in step (a) is above the initial gelatinization temperature.
9. The process of claim 7 wherein a protease is added in step (a) carried out above the initial gelatinization temperature.
10. The process of claim 7 , wherein the protease further comprises the one shown in SEQ ID NO: 4 herein, or wherein the protease has at least 90% identity SEQ ID NO: 4 having a protease activity.
11. The process of claim 7 , wherein the protease, added in step (a) carried out at a temperature above the initial gelatinization temperature, has:
(i) a thermostability of more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 100%, more than 105%, more than 110%, more than 115%, or more than 120% determined as Relative Activity at 80° C./70° C.;
(ii) a thermostability between 50 and 115% determined as Relative Activity at 80° C./70° C.; or
(iii) a thermostability of more than 12%, more than 14%, more than 16%, more than 18%, more than 20%, more than 25%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 100%, or more than 110% determined as Relative Activity at 85° C./70° C.
12. The process of claim 7 , wherein the bacterial alpha-amylase is from the genus Bacillus.
13. The process of claim 1 , wherein the step (a) is performed at a temperature below the initial gelatinization temperature.
14. The process of claim 13 , wherein:
(i) saccharification step (b) and fermentation step (c) are carried out simultaneously or sequentially; or
(ii) steps (a), (b) and (c) are carried out simultaneously or sequentially at a temperature below the initial gelatinization temperature.
15. The process of claim 12 , wherein the alpha-amylase is a Bacillus stearothermophilus alpha-amylase.
16. The process of claim 12 , wherein the alpha-amylase is a variant of the Bacillus stearothermophilus alpha-amylase shown in SEQ ID NO: 1 herein having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity thereto.
17. The process of claim 12 , wherein the alpha-amylase is truncated.
18. The process of claim 17 , wherein the alpha-amylase is truncated to have from 485-495 amino acids.
19. The process of claim 17 , wherein the alpha-amylase is truncated to have around 491 amino acids.