Extraction of lipid from cells and products therefrom

Abstract

The present invention relates to processes for obtaining a lipid from a cell by lysing the cell, contacting the cell with a base and/or salt, and separating the lipid. The present invention is also directed to a lipid prepared by the processes of the present invention. The present invention is also directed to microbial lipids having a particular anisidine value, peroxide value, and/or phosphorus content.

What is claimed is: 
     
         1 . A process for obtaining a lipid from a microbial cell composition, comprising:
 raising the pH of the cell composition to 8 or above; and   separating a lipid from the cell composition,   wherein the lipid contains less than 5% by weight of an organic solvent.   
     
     
         2 . The process of  claim 1 , wherein the raising the pH lyses the cell composition. 
     
     
         3 . The process of  claim 1 , wherein the raising the pH demulsifies the cell composition. 
     
     
         4 . The process of any of  claims 1 - 3 , further comprising adding a salt to the cell composition to demulsify the cell composition. 
     
     
         5 . The process of  claim 4 , wherein the adding a salt is performed after the raising the pH. 
     
     
         6 . The process of any of  claims 1 - 5 , further comprising heating the cell composition to demulsify the cell composition. 
     
     
         7 . The process of  claim 6 , wherein the heating is performed after the raising the pH. 
     
     
         8 . The process of any of  claims 1 - 7 , further comprising raising the pH of the cell composition a second time to demulsify the cell composition. 
     
     
         9 . The process of  claim 8 , wherein the raising the pH a second time is performed after the adding a salt or the heating. 
     
     
         10 . A process for obtaining a lipid from a cell, comprising:
 lysing a cell to form a lysed cell composition;   raising the pH of the lysed cell composition to 8 or above to demulsify the cell composition;   adding a salt to the lysed cell composition to demulsify the cell composition; and   separating a lipid from the demulsified cell composition,   wherein the lipid contains less than 5% by weight of an organic solvent.   
     
     
         11 . A process for obtaining a lipid from a cell composition, comprising:
 raising the pH of a cell composition to 8 or above to lyse the cell composition and demulsify the cell composition;   adding a salt to the cell composition; and   separating a lipid from the demulsified cell composition,   wherein the lipid contains less than 5% by weight of an organic solvent.   
     
     
         12 . The process of  claim 10  or  11 , further comprising heating the lysed cell composition to demulsify the cell composition. 
     
     
         13 . The process of  claim 12 , wherein the heating is performed after the adding a salt. 
     
     
         14 . The process of any of  claims 1 - 13 , further comprising agitating the lysed cell composition to demulsify the cell composition. 
     
     
         15 . The process of any of  claims 10 - 14 , further comprising raising a pH of the lysed cell composition to demulsify the cell composition. 
     
     
         16 . The process of  claim 15 , wherein the raising the pH of the lysed cell composition is performed after the adding a salt or the heating. 
     
     
         17 . The process of any of  claims 1 - 16 , wherein raising the pH comprises adding a base. 
     
     
         18 . The process of any of  claims 1 - 17 , wherein the base has a pK b  of 1 to 12. 
     
     
         19 . The process of any of  claims 14 - 18 , wherein the process comprises agitating the lysed cell composition by stirring, mixing, blending, shaking, vibrating, or a combination thereof. 
     
     
         20 . The process of any of  claims 1 - 19 , wherein the lysing comprises mechanical treatment, physical treatment, chemical treatment, enzymatic treatment, or a combination thereof. 
     
     
         21 . The process of  claim 20 , wherein the mechanical treatment is homogenization. 
     
     
         22 . The process of any of  claims 4 - 21 , wherein the salt is added in an amount of 0.1% to 20% by weight of the lysed cell composition. 
     
     
         23 . The process of any of  claims 4 - 22 , wherein the salt is selected from the group consisting of: alkali metal salts, alkali earth metal salts, sulfate salts, and combinations thereof. 
     
     
         24 . The process of any of  claims 1 - 23 , wherein the separating comprises centrifuging. 
     
     
         25 . The process of any of  claims 1 - 24 , wherein the process provides a lipid comprising at least 50% by weight triglyceride. 
     
     
         26 . The process of any of  claims 1 - 25 , wherein the process provides a lipid having an anisidine value of 26 or less. 
     
     
         27 . The process of any of  claims 10 - 26 , wherein the cell is a microbial cell. 
     
     
         28 . The process of any of  claims 1 - 9  and  27 , further comprising concentrating a fermentation broth comprising the microbial cell. 
     
     
         29 . The process of any of  claims 10 - 26 , wherein the cell is an oilseed. 
     
     
         30 . The process of  claim 29 , wherein the oilseed is selected from the group consisting of sunflower seeds, canola seeds, rapeseeds, linseeds, castor oil seeds, coriander seeds, calendula seeds, and genetically modified variants thereof. 
     
     
         31 . The process of any of  claims 1 - 30 , further comprising washing the cell or cell composition. 
     
     
         32 . The process of any of  claims 1 - 31 , further comprising pasteurizing the cell or cell composition. 
     
     
         33 . The process of any of  claims 1 - 32 , further comprising concentrating the lysed cell composition. 
     
     
         34 . The process of any of  claims 1 - 33 , further comprising refining the lipid. 
     
     
         35 . The process of  claim 34 , wherein the refining is selected from the group consisting of: refining, degumming, acid treatment, alkali treatment, cooling, heating, bleaching, deodorizing, deacidification, and combinations thereof. 
     
     
         36 . The process of any of  claims 1 - 35 , further comprising harvesting the lipid, wherein the harvesting comprises pumping the lipid without agitation. 
     
     
         37 . A process for obtaining a lipid from a cell, comprising:
 lysing a cell to form a lysed cell composition;   agitating the cell composition to demulsify the cell composition; and   separating a lipid from the demulsified cell composition,   wherein the lipid contains less than 5% by weight of an organic solvent.   
     
     
         38 . A process of  claim 37 , wherein the agitating comprises agitating the cell composition with an impeller having a tip speed of 350 centimeters per second to 900 centimeters per second. 
     
     
         39 . A lipid obtained by the process of any of  claims 1 - 38 . 
     
     
         40 . The lipid of  claim 39 , wherein the lipid comprises one or more polyunsaturated fatty acids. 
     
     
         41 . The lipid of any of  claims 39 - 40 , wherein the lipid comprises at least 35% by weight docosahexaenoic acid. 
     
     
         42 . The lipid of any of  claims 39 - 41 , wherein the lipid has an overall aroma intensity of 3 or less. 
     
     
         43 . The lipid of any of  claims 39 - 41 , wherein the lipid has an overall aromatic intensity of 2 or less. 
     
     
         44 . The lipid of any of  claims 39 - 43 , wherein the lipid has an anisidine value of 26 or less. 
     
     
         45 . The lipid of any of  claims 39 - 44 , wherein the lipid has a phosphorus content of 100 ppm or less. 
     
     
         46 . The lipid of any of  claims 39 - 45 , wherein the lipid has a peroxide value of 5 or less. 
     
     
         47 . The lipid of  claim 39 , comprising at least 20% by weight eicosapentaenoic acid and less than 5% by weight each of arachidonic acid, docosapentaenoic acid n-6, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, erucic acid, and stearidonic acid. 
     
     
         48 . The lipid of  claim 39 , comprising a triacylglycerol fraction of at least 10% by weight, wherein at least 12% by weight of the fatty acids in the triacylglycerol fraction is eicosapentaenoic acid, wherein at least 25% by weight of the fatty acids in the triacylglycerol fraction is docosahexaenoic acid, and wherein less than 5% by weight of the fatty acids in the triacylglycerol fraction is arachidonic acid. 
     
     
         49 . The lipid of  claim 47  or  48 , wherein the lipid has a peroxide value of 5 or less. 
     
     
         50 . The lipid of any of  claims 39 - 49 , wherein the lipid is a crude oil. 
     
     
         51 . A crude microbial lipid having an anisidine value of 26 or less, a peroxide value of 5 or less, a phosphorus content of 100 ppm or less, and less than 5% by weight of an organic solvent. 
     
     
         52 . An extracted microbial lipid comprising a triglyceride fraction of at least 70% by weight, wherein the docosahexaenoic acid content of the triglyceride fraction is at least 50% by weight, wherein the docosapentaenoic acid n-6 content of the triglyceride fraction is from at least 0.5% by weight to 6% by weight, and wherein the oil has an anisidine value of 26 or less. 
     
     
         53 . An extracted microbial lipid comprising a triglyceride fraction of at least 70% by weight, wherein the docosahexaenoic acid content of the triglyceride fraction is at least 40% by weight, wherein the docosapentaenoic acid n-6 content of the triglyceride fraction is from at least 0.5% by weight to 6% by weight, wherein the ratio of docosahexaenoic acid to docosapentaenoic acid n-6 is greater than 6:1, and wherein the oil has an anisidine value of 26 or less. 
     
     
         54 . An extracted microbial lipid comprising a triglyceride fraction of at least about 70% by weight, wherein the docosahexaenoic acid content of the triglyceride fraction is at least 60% by weight and wherein the oil has an anisidine value of 26 or less. 
     
     
         55 . The extracted microbial lipid of any of  claims 52 - 54 , wherein the oil has a peroxide value of 5 or less. 
     
     
         56 . The extracted microbial lipid of any of  claims 52 - 55 , wherein the oil has a phosphorus content of 100 ppm or less. 
     
     
         57 . The extracted microbial lipid of any of  claims 52 - 56 , wherein the lipid is a crude oil. 
     
     
         58 . A process for obtaining a lipid, the process comprising refining a crude lipid of any of  claims 50 ,  51 , or  57 . 
     
     
         59 . The process of  claim 58 , wherein the refining is selected from the group consisting of: caustic refining, degumming, acid treatment, alkali treatment, bleaching, deodorizing, deacidification, and combinations thereof.