Processes for obtaining microbial oil from microbial cells

• US 10,364,207 B2
• Filed: 12/19/2014
• Issued: 07/30/2019
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Inventors: Barker, Mark, Tabayehnejad, Nasrin, Shank, Ginger, Leininger, Neil Francis, Matthews, Sr., Kirt Lyvell
• Primary Examiner(s): Ware, Deborah K
• Application Number:
  US15/106,371
• Publication Number:
  US 20160318840A1
• Time in Patent Office: 1,684 Days
• CPC Class Codes: A23D 9/00 Other edible oils or fats, e.g. shortenings, cooking oils
• CPC Class Codes: C07C 51/48 by liquid-liquid treatment
• CPC Class Codes: C11B 1/025 by enzymes or microorganisms, living or dead
• CPC Class Codes: C11B 3/00 Refining fats or fatty oils
• CPC Class Codes: C11B 3/06 with bases
• CPC Class Codes: C12N 1/066 by physical methods
• CPC Class Codes: C12P 7/6472 containing polyunsaturated fatty acid [PUFA] residues, i.e. having two or more double bonds in their backbone

Abstract

Disclosed herein are processes for obtaining a microbial oil comprising one or more polyunsaturated fatty acids (PU-FAs) from one or more microbial cells by lysing the cells to form a lysed cell composition and then recovering the oil from the lysed cell composition. Further disclosed herein is microbial oil comprising one or more PUFAs that is recovered from microbial cells by at least one process described herein.

Claims

1. A process for obtaining a microbial oil comprising one or more polyunsaturated fatty acids from one or more microbial cells, wherein the process comprises:

(a) lysing the cells comprising the microbial oil to form a lysed cell composition;

(b) demulsifying the lysed cell composition to form a demulsified lysed cell composition;

(c) separating the oil from the demulsified lysed cell composition; and

(d) recovering the oil;

wherein (b) comprises adding at least one enzyme selected from the group consisting of beta-glucanase, xylanase, cellulase, pectinase, mannanase, amylase, and combinations thereof, and wherein at least one of (a) or (b) further comprises heating the cells or the composition to at least 60°

C.

2. The process of claim 1, wherein at least one of (a) or (b) further comprises heating the cells or the composition to from about 60°

C. to about 100°

C.

3. The process of claim 1, wherein (b) further comprises adding a base to the lysed cell composition.

4. The process of claim 1, wherein (b) further comprises raising the pH of the lysed cell composition to about 8 or above.

5. The process of claim 1, wherein (b) further comprises adding a salt in an amount of from about 0.05% to about 20%, by weight, of the lysed cell composition.

6. The process of claim 1, wherein (b) further comprises agitating the lysed cell composition.

7. The process of claim 1, wherein (a) further comprises agitating the cells.

8. The process of claim 1, wherein (b) further comprises adding an emulsifier to the lysed cell composition.

9. The process of claim 1, wherein the cells of (a) are unwashed.

10. The process of claim 1, wherein the cells of (a) are contained in a fermentation broth.

11. The process of claim 1, wherein (c) comprises centrifuging the demulsified lysed cell composition.

12. The process of claim 1, wherein the polyunsaturated fatty acid is selected from an omega-3 fatty acid, an omega-6 fatty acid, and mixtures thereof.

13. The process of claim 1, wherein the polyunsaturated fatty acid is selected from docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), arachidonic acid (ARA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), stearidonic acid (SDA), and mixtures thereof.

14. The process of claim 13, wherein the polyunsaturated fatty acid is docosahexaenoic acid (DHA).

15. The process of claim 13, wherein the polyunsaturated fatty acid is arachidonic acid (ARA).

16. The process of claim 1, wherein the microbial cells are algae, yeast, fungi, protist, or bacteria cells.

17. The process of claim 1, wherein the microbial cells are from the genus Mortierella, genus Crypthecodinium, or order Thraustochytriales.

18. The process of claim 16, wherein the microbial cells are from the order Thraustochytriales.

19. The process of claim 17, wherein the microbial cells are from the genus Thraustochytrium, Schizochytrium, or mixtures thereof.

20. The process of claim 16, wherein the microbial cells are from Mortierella Alpina.

21. The process of claim 1, wherein the lysed cell composition comprises liquid, cell debris, and microbial oil.

22. The process of claim 1, wherein an organic solvent is not used to obtain the oil from the cells.

23. The process of claim 1, wherein the mean particle size of the demulsified lysed cell composition is at least 10 microns.

24. The process of claim 1, wherein the enzyme is a beta-glucanase.

25. The process of claim 1, wherein the enzyme is added in an amount of from about 0.05% to about 10% by weight of the lysed cell composition.

26. The process of claim 8, wherein the emulsifier is an ionic emulsifier.

27. The process of claim 5, wherein the salt is selected from the group consisting of alkali metal salts, alkali earth metal salts, sulfate salts, and combinations thereof.

28. The process of claim 1, wherein the oil of (d) is a crude oil.

29. The process of claim 28, wherein (d) further comprises refining the crude oil to obtain a refined oil.

30. The process of claim 1, wherein the oil comprises at least 30% by weight arachidonic acid.

31. The process of claim 1, wherein the oil comprises at least 30% by weight docosahexaenoic acid.

32. The process of claim 1, wherein the oil has an anisidine value of less than about 50.

33. The process of claim 1, wherein the oil has a phosphorus content of about 8 ppm or less.

34. The process of claim 1, wherein the oil has a peroxide value of less than about 5 meq/kg.

35. The process of claim 1, wherein (b) further comprises lowering the pH to about 6 or less by adding an acid.

36. The process of claim 1, wherein (b) further comprises lowering the pH of the lysed cell composition to a range of from about 0.5 to about 6.

37. The process of claim 1, wherein (b) further comprises adding an acid in an amount of from about 0.5% to about 20%, by weight, lysed cell composition.

38. The process according to claim 1, wherein (a) and (b) are combined together to form a one-step lysing and demulsifying step.

39. The process according to claim 1, wherein (c) further comprises raising the pH of the demulsified lysed cell composition.

40. An oil obtained by the process of claim 1, wherein the oil has at least one of the following:

(i) at least 50% by weight docosahexaenoic acid;

(ii) an anisidine value of less than about 10; and

/or

(iii) a peroxide value of less than about 5 meg/kg.

41. The oil of claim 40, wherein the oil is a crude oil.

42. The oil of claim 41, wherein the crude oil is refined to obtain a refined oil.

43. A process for obtaining a microbial oil comprising one or more polyunsaturated fatty acids from one or more microbial cells, wherein the process comprises:

(a) lysing the cells comprising the microbial oil to form a lysed cell composition;

(b) demulsifying the lysed cell composition to form a demulsified lysed cell composition;

(c) separating the oil from the demulsified lysed cell composition; and

(d) recovering the oil;

wherein (a) and (b) are combined together to form a one-step lysing and demulsifying step that comprises adding at least one enzyme selected from the group consisting of beta-glucanase, xylanase, cellulase, pectinase, mannanase, amylase, and combinations thereof.