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BR-112020023222-B1 - METHOD FOR ISOLATING LIPIDS FROM A BIOMASS CONTAINING LIPIDS

BR112020023222B1BR 112020023222 B1BR112020023222 B1BR 112020023222B1BR-112020023222-B1

Abstract

METHOD FOR ISOLATING LIPIDS FROM A BIOMASS CONTAINING LIPIDS LYSED BY EMULSION INVERSION. The present invention relates to a method for separating lipids from a biomass containing lipids by demulsification under mild conditions, to an oil and to a delipidized biomass as obtained by such method.

Inventors

  • ANNIKA HEINING
  • Martin Heining

Assignees

  • EVONIK OPERATIONS GMBH
  • DSM IP ASSETS B.V

Dates

Publication Date
20260317
Application Date
20190502
Priority Date
20180515

Claims (10)

  1. 1. A method for isolating lipids from a lipid-containing biomass without the use of any organic solvent, characterized by comprising the following steps: a) Providing a suspension of a biomass comprising cells containing a lipid; b) Lysing the biomass cells; c) Concentrating the suspension obtained in step b) until the volume ratio between oil and water in the suspension exceeds the value of 1, wherein the suspension is concentrated to a total dry matter (TDM) content between 65 and 90% by weight and wherein the concentration of the suspension is carried out by evaporating water at a temperature between 70 °C and 100 °C; d) Separating the light phase containing oil from the aqueous phase.
  2. 2. Method according to claim 1, characterized in that the suspension is concentrated to a TDM content between 65 and 80% by weight.
  3. 3. A method, according to any of the preceding claims, characterized in that the concentration of the suspension is carried out by evaporation of water at a temperature between 80 °C and 90 °C.
  4. 4. A method, according to any of the preceding claims, characterized in that the lysis of biomass cells is carried out enzymatically, mechanically, chemically, or physically.
  5. 5. A method, according to any of the preceding claims, characterized in that the suspension is provided as a fermentation broth and/or with a biomass density of at least 80 or 100 g/l, in particular, from 80 or 100 g/l to 250 g/l, preferably at least 120 or 140 g/l, in particular, 120 or 140 g/l to 220 g/l, more preferably at least 160 or 180 g/l, in particular, 160 g/l to 200 g/l.
  6. 6. A method, according to any of the preceding claims, characterized in that the biomass cells comprise at least 10% by weight of lipids, preferably 20 or 30% by weight of lipids, more preferably 40 or 50% by weight of lipids.
  7. 7. A method, according to any of the preceding claims, characterized in that the cells containing the lipids contain a lipid containing PUFAs and are selected from algae, fungi, protists, bacteria, microalgae, plant cells, and mixtures thereof, wherein the microalgae are preferentially selected from the phylum Stramanopiles, in particular, from the family Thraustochytrids.
  8. 8. Method, according to any of the preceding claims, the method being characterized in that it is carried out without the addition of solvents or caustic products.
  9. 9. Method, according to any of the preceding claims, the method being characterized in that it is carried out without the addition of any solvents, caustic soda or sodium hydroxide.
  10. 10. A method, according to any of the preceding claims, characterized in that the pH is maintained between 4.5 and 9, in particular between 4.5 and 8.5, during the entire process.

Description

[0001] The present invention relates to a method for separating lipids from a lipid-containing biomass by demulsification under mild conditions. [0002] Lipids containing PUFAs (polyunsaturated fatty acids) are of great interest in the feed, food, and pharmaceutical industries. Due to overfishing, there is a great need for alternative sources of PUFA-containing lipids besides fish oil. It has been found that, in addition to certain yeast and algal strains, in particular, microalgae cells, such as those of the order Thraustochytriales, are a very good source of PUFA-containing lipids. [0003] However, with regard to microbial organisms and, in particular, cells of the order Thraustochytriales, which produce lipids containing PUFAs, isolating the oil from the cells has proven to be a particular problem. The most effective way to isolate the oil was by using organic solvents such as hexane. However, the use of organic solvents results in hazardous operating conditions, requires the use of expensive explosion-proof equipment, and necessitates the implementation of a costly solvent recovery process to avoid environmental pollution. [0004] In an attempt to avoid the use of organic solvents as an effective alternative for isolating the oil, relabeling the oil with large quantities of sodium chloride was found. However, the use of large quantities of sodium chloride results in a delipidated biomass byproduct which, due to its high salt content, cannot be used as a feed ingredient, making the process not very sustainable. In addition, the high salt concentration results in rapid corrosion of the steel equipment used. [0005] Thus, it was an objective of the present invention to provide an effective method for isolating a lipid, in particular a lipid containing PUFAs, from lipid-containing cells, in particular of the order Thraustochytriales, and simultaneously avoiding not only the need for organic solvents, but also avoiding the need for large amounts of salts and, preferably, also avoiding the use of large amounts of base and/or a high pH to achieve the effective isolation of the oil from the cells. [0006] It was also an objective of the present invention to provide a method for isolating a lipid, in particular a lipid containing PUFAs, from lipid-containing cells, in particular of the order Thraustochytriales, and simultaneously providing a lipid-free biomass that can be used in a commercial manner, preferably in the agricultural field. [0007] It has been revealed that an effective separation of the lipid from the aqueous phase containing cellular debris can be surprisingly achieved if the biomass, in particular after lysis, is concentrated until the volume ratio between the oil and water in the suspension exceeds the value of 1. By concentrating the suspension to a very high oil content, a spontaneous breakdown of the emulsion as contained in the suspension occurs. This spontaneous breakdown of the emulsion is also called “demulsification” or “emulsion inversion” in the context of this application. [0008] The great advantage of this process lies in the fact that it can be carried out without the addition of solvents, without the addition of salts such as sodium chloride for salting the oil, as well as without the addition of caustics, in particular, without the addition of caustic products at high temperatures, so that an ecological, sustainable, and mild method for isolating lipids from cells is provided. [0009] Thus, a first material aspect of the present invention is a method for isolating a lipid from a lipid-containing biomass, comprising the following steps: a) Providing a suspension of a biomass comprising cells containing a lipid; b) Optionally lysing the biomass cells; c) Concentrating the suspension until the volume ratio of oil to water in the suspension exceeds the value of 1; d) Separating the light phase containing oil from water, salts, cell debris and aqueous phase containing residual oil. [0010] Preferably, the suspension is concentrated until the volume ratio between oil and water in the suspension reaches a value between 1 and 2, more preferably between 1 and 1.5, in particular between 1 and 1.2. [0011] In a preferred embodiment of the invention, the suspension is concentrated to a total dry matter (TDM) content of more than 60% by weight, preferably to a TDM content between 60 and 98% by weight or between 61 and 98% by weight, more preferably to a TDM content between 60 and 80% by weight or between 62 and 80% by weight or between 62 and 85% by weight or between 65 and 90% by weight or between 65 and 80% by weight, in particular to a TDM content between 60 and 75% by weight or between 62 and 75% by weight. [0012] According to the invention, the concentration of the suspension is preferably carried out by evaporating water at a temperature not higher than 100 °C, preferably at a temperature of 70 °C to 100 °C, more preferably 80 °C to 90 °C. [0013] The concentration of the suspension is preferably