Method of enhancing lipid production in algae and applications thereof

Patent metadata

Field	Value
Publication number	US-12439868-B2
Application number	US-202117186834-A
Country	US
Kind code	B2
Filing date	Feb 26, 2021
Priority date	Feb 27, 2020
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

The present disclosure relates to the field of algal cultivation and biofuels. Particularly, the present disclosure relates to a method of enhancing lipid production during algal culturing. Particularly, the present disclosure relates to a method of enhancing neutral lipid and total lipid production by maintaining algae in a thin layer cultivation system and exposing said algae maintained in the thin layer cultivation system to infra-red (IR) radiation. Said method enhances lipid accumulation in algae, thereby increasing the yield of neutral lipids and total lipids. The method is simple, cost-effective in producing high quantities of algal-derived biofuels, requires shorter time duration for lipid induction and results in no or minimal reduction of biomass.

First claim

We claim:

1. A method of enhancing lipid production in algae, said method comprising:
(a) culturing algae in a condition of nutrient repletion followed by nutrient depletion;
(b) subsequently maintaining said algae in a thin layer cultivation system at a culture depth of about 1 cm to 10 cm, wherein the algae is subjected to non-shear mixing in the thin layer cultivation system to provide equal exposure to sunlight and CO 2 , wherein said algae is maintained in nutrient deplete conditions in said thin layer cultivation system, wherein the algae maintained in the thin layer cultivation system is concentrated algal culture having a cell density ranging from about 5 g/L to 100 g/L, and
(c) exposing said algae maintained in the thin layer cultivation system to infra-red (IR) radiation.

2. The method of claim 1 ,
and
wherein the nutrient depletion comprises depletion of one or more of Nitrogen and Phosphorus.

3. The method of claim 1 , wherein the algae is microalgae selected from the group consisting of green algae, diatoms, red algae, brown algae, gold algae, yellow-green algae, and cyanobacteria, and combinations thereof; and wherein the lipid is total lipid, neutral lipid or a combination thereof; and
wherein the green algae is selected from the group consisting of Picochlorum, Nannochloropsis, Nannochloris, Chlorella, Cyclotella , and Navicula , and combinations thereof; and the cyanobacteria is one or more of Cyanobacterium aponinum and Synechococcus elongatus.

4. The method of claim 1 , wherein the algae is exposed to IR radiation after about 1 minute to 48 hours; or wherein the algae is exposed to IR radiation of a wavelength ranging from about 700 nm to 1200 nm; or wherein the algae is exposed to IR radiation after about 1 minute to 48 hours, and wherein the algae is exposed to IR radiation of a wavelength ranging from about 700 nm to 1200 nm.

5. The method of claim 1 , wherein the algae is exposed to the IR radiation for a time-period ranging from about 1 second to 60 minutes.

6. The method of claim 1 , wherein the algae is exposed to the IR radiation for a time-period ranging from about 5 minutes to 30 minutes.

7. The method of claim 1 , wherein IR radiation source is employed to generate the IR radiation, and wherein distance between the IR radiation source and the algae ranges from about 1 cm to 100 cm;
or wherein the thin layer cultivation system is an open or closed system, and wherein said thin layer cultivation system is selected from the group consisting of a culture pond, a horizontal reactor, a vertical reactor, a tubular reactor, a flat panel reactor, and combinations thereof; or wherein IR radiation source is employed to generate the IR radiation, and wherein distance between the IR radiation source and the algae ranges from about 1 cm to 100 cm, and wherein the thin layer cultivation system is an open or closed system, and wherein said thin layer cultivation system is selected from the group consisting of a culture pond, a horizontal reactor, a vertical reactor, a tubular reactor, a flat panel reactor, and combinations thereof.

8. The method of claim 1 , wherein the algae maintained in the thin layer cultivation system is exposed to carbon dioxide (CO 2 ) and sunlight; and wherein a concentration of the CO 2 ranges from about 0.03% to 100% and an intensity of the sunlight ranges from about 1800 μmol/m 2 /s to 2000 μmol/m 2 /s.

9. The method of claim 1 , wherein the thin layer cultivation system is maintained at a temperature ranging from about 30° C. to 35° C.

10. The method of claim 1 , wherein the method further comprises, after step (a) and prior to step (b):
(i) harvesting the cultured algae; and (ii) concentrating the harvested algae.

11. The method of claim 1 , wherein the step of maintaining the concentrated algae in a thin layer cultivation system further comprises simultaneous exposure of the algae to CO 2 at a concentration of about 0.1% to 100% and sunlight of intensity ranging from about 1800 μmol/m 2 /s to 2000 μmol/m 2 /s.

12. The method of claim 1 , further comprising:
harvesting the algae maintained in the thin layer cultivation system;
drying the harvested algae to obtain a powdered algae; and
extracting the powdered algae with a solvent to obtain a lipid.

13. The method of claim 1 , wherein enhancing lipid production in algae comprises enhancing total lipid production, and enhancement of total lipid yield is at least about 8% as compared to the yield of total lipid from untreated algae which is not maintained according to the method of claim 1 .

14. The method of claim 1 , wherein enhancing lipid production in algae comprises enhancing neutral lipid production, and enhancement of neutral lipid yield is at least about 30% as compared to the yield of neutral lipid from untreated algae which is not maintained according to the method of claim 1 .

Assignees

• Reliance Industries Ltd

Inventors

• Kumar Gurumurthy Raja Krishna
• Chelliah Meenakshi Sundaram
• Rajvanshi Meghna
• Subhash G Venkata
• Gohil Dhairyarajsinh Rajendrasinh
• Govindachary Sridharan
• Dasgupta Santanu

Classifications

• C12P7/649

  Biodiesel, i.e. fatty acid alkyl esters · CPC title

• A01G33/00

  Cultivation of seaweed {or algae} · CPC title

• C12N1/12

  Unicellular algae; Culture media therefor (as new plants A01H13/00) · CPC title

• A01H13/00

  Algae (unicellular algae C12N1/12) · CPC title

• A01N3/00

  Preservation of plants or parts thereof, e.g. inhibiting evaporation, improvement of the appearance of leaves {or protection against physical influences such as UV radiation using chemical compositions} (preservation or chemical ripening of fruit or vegetables A23B7/00); Grafting wax · CPC title