Method of separating lipids from a lysed lipids containing biomass

1. A method of separating polyunsaturated fatty acids (PUFAs) containing lipid from the debris of a biomass, comprising the steps:

a) providing a suspension of a biomass comprising cells which contain a PUFAs containing lipid;

b) lysing the cells of the biomass;

c) adding acetone to the suspension obtained in step (b) until a final amount of between 25 and 47.5 wt.-% of acetone is reached;

d) thoroughly mixing the suspension obtained in step (c);

e) separating an oil containing PUFAs and acetone-containing light phase obtained in step (d) from a water, acetone, salt and cell debris containing heavy phase.

2. The method of claim 1 , wherein acetone is added to the suspension of biomass in step (c) until a final amount of between 27.5 and 45.0, wt.-% of acetone is reached.

3. The method of claim 1 , wherein mixing of the suspension in step (d) is carried out by shaking, stirring and/or vortexing.

4. The method of claim 1 , wherein lysing of the cells of the biomass is carried out enzymatically, mechanically, chemically and/or physically.

5. The method of claim 4 , wherein lysing of the cells of the biomass comprises an enzymatic treatment of the cells with a cell wall degrading enzyme.

6. The method of claim 5 , wherein lysing of the cells of the biomass is carried by a method comprising:

a) heating the suspension of biomass to a temperature of between 50° C. and 70° C., adding a cell wall-degrading enzyme to the fermentation broth, and, if necessary, adjusting the pH to a value at which the enzyme is active;

b) maintaining the temperature and pH in the ranges of paragraph a) for at least one hour.

7. The method of claim 1 , wherein after lysing the cells, the suspension is concentrated to a total dry matter content of 30 to 60 wt-%.

8. The method of claim 1 , wherein steps (c) to (e) are carried out at a temperature of 10 to 50° C.

9. The method of claim 1 , wherein, before addition of acetone in step (c), the pH of the suspension is adjusted to an acidic pH.

10. The method of claim 9 , wherein before addition of acetone in step (c), the pH is adjusted to a an acidic pH of 2.5 to 6.8.

11. The method of claim 1 , wherein separation of the oil and acetone-containing light phase from the water, acetone, salt and cell debris containing heavy phase is realized by mechanical means.

12. The method of claim 11 , wherein separation of the oil and acetone-containing light phase from the water, acetone, salt and cell debris containing heavy phase by mechanical means takes place at a pH of 5.5 to 8.5.

13. The method of claim 1 , further comprising separating the acetone from the PUFAs containing oil.

14. The method of claim 1 , wherein the suspension has a biomass density of at least 80 g/l.

15. The method of claim 1 , wherein the suspension has a biomass density of at least 140 g/l.

16. The method of claim 1 , wherein the cells which contain a PUFAs containing lipid are selected from the group consisting of: algae; fungi; protists;

bacteria; microalgae; plant cells; and mixtures thereof.

17. The method of claim 16 , wherein the cells which contain a PUFAs containing lipid are microalgae selected from the phylum Stramanopiles.

18. The method of claim 17 , wherein the cells which contain a PUFAs containing lipid are from the family Thraustochytrids.

19. The method of claim 18 , wherein the cells which contain a PUFAs containing lipid are microalgae of the genus Schizochytrium.

20. The method of claim 5 , wherein the cell-wall degrading enzyme is selected from the group consisting of: a protease, cellulase, hemicellulase, chitinase, pectinase, sucrase, maltase, lactase, alpha-glucosidase, beta-glucosidase, amylase, lysozyme, neuraminidase, galactosidase, alpha-mannosidase, glucuronidase, hyaluronidase, pullulanase, glucocerebrosidase, galactosylceramidase, acetylgalactosaminidase, fucosidase, hexosaminidase, iduronidase, maltase-glucoamylase, beta-glucanase, mannanase, and combinations thereof.