Methods of recovering oil from microorganisms

• US 9,745,538 B2
• Filed: 12/19/2014
• Issued: 08/29/2017
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Mara Renewables Corporation
• Original Assignee: Mara Renewables Corporation
• Inventors: Dennis, Dorothy A., Armenta, Roberto E.
• Primary Examiner(s): Kim, Taeyoon
• Assistant Examiner(s): GOUGH, TIFFANY MAUREEN
• Application Number:
  US14/577,471
• Publication Number:
  US 20150176042A1
• Time in Patent Office: 984 Days
• CPC Class Codes: C11B 1/025 by enzymes or microorganisms, living or dead
• CPC Class Codes: C11B 1/06 by pressing
• CPC Class Codes: C11B 1/10 by extracting
• CPC Class Codes: C12P 7/6427 Polyunsaturated fatty acids [PUFA], i.e. having two or more double bonds in their backbone
• CPC Class Codes: C12P 7/6434 Docosahexenoic acids [DHA]
• CPC Class Codes: C12P 7/6458 by transesterification, e.g. interesterification, ester interchange, alcoholysis or acidolysis
• CPC Class Codes: C12P 7/6463 obtained from glyceride producing microorganisms, e.g. single cell oil
• CPC Class Codes: C12P 7/6472 containing polyunsaturated fatty acid [PUFA] residues, i.e. having two or more double bonds in their backbone

Abstract

Provided herein are methods of recovering oil from microorganisms. The methods are useful, for example, in obtaining nutritional oils and/or lipid biofuels. The methods of recovering oil described herein include contacting a population of microorganisms with one or more enzymes under conditions that cause disruption of the microorganisms, concentrating the disrupted microorganisms, and extracting lipids from the disrupted microorganisms at high temperature in the presence of a salt and in the absence of solvent.

Claims

1. A method of recovering lipids from a population of lipid-producing microorganisms comprising:

(a) contacting the population of lipid-producing microorganisms with one or more enzymes under conditions that cause disruption of the microorganisms;

(b) concentrating the disrupted microorganisms with the lipids by (i) producing a heavy layer and a light layer, wherein the light layer comprises substantially all of the disrupted microorganisms and lipids and (ii) removing at least a portion of the heavy layer; and

(c) extracting lipids from the concentrated disrupted microorganisms and lipids of step (b) at a high temperature in the presence of a salt in the absence of organic solvents, wherein extraction separates the lipids from the microorganisms and wherein the method lacks a pasteurization step prior to the contacting step.

2. The method of claim 1, wherein the contacting step is performed at a pH of from 5 to 8.5.

3. The method of claim 1, wherein the contacting step is performed at a temperature of from about 50°

C. to about 70°

C.

4. The method of claim 1, wherein the contacting step is performed for one to twenty hours.

5. The method of claim 1, wherein the contacting step is performed for one to eight hours.

6. The method of claim 1, wherein the enzyme is a protease.

7. The method of claim 6, wherein the enzyme is Alcalase 2.4 L.

8. The method of claim 1, wherein the concentration of enzyme is between 0.001 and 0.4% volume/volume.

9. The method of claim 1, wherein the concentration of enzyme is between 0.05 and 0.2% volume/volume.

10. The method of claim 1, wherein the contacting step is performed in the presence of 0.05% to 0.2% enzyme for one to eight hours at about 55°

C.

11. The method of claim 1, wherein the contacting step is performed in the absence of surfactants.

12. The method of claim 1, wherein the concentrating step comprises centrifugation.

13. The method of claim 1, wherein the concentrating step comprises 25% to 95% aqueous removal.

14. The method of claim 1, wherein the high temperature during the extraction step is from 75°

C. to 95°

C.

15. The method of claim 14, wherein the high temperature during the extraction step is 85°

C.

16. The method of claim 1, wherein the concentration of salt added during the extraction step is from 1% to 5%.

17. The method of claim 16, wherein the concentration of salt added during the extraction step is from 3% to 5%.

18. The method of claim 1, wherein the salt added during the extraction step is sodium sulfate.

19. The method of claim 1, wherein the extracting step is performed in the presence of oil.

20. The method of claim 19, wherein the oil is coconut oil.

21. The method of claim 1, wherein the extracting step is performed in the presence of biofuel.

22. The method of claim 1, wherein the population of microorganisms is selected from the group consisting of algae, fungi, bacteria and protists.

23. The method of claim 22, wherein the population of microorganisms is selected from the genus Thraustochytrium, Schizochytrium and mixtures thereof.

24. The method of claim 23, wherein the population of microorganisms is a Thraustochytrium sp. deposited as ATCC Accession No. PTA-6245.

25. The method of claim 1, wherein the lipids comprise docosahexaenoic acid.