Microalgae fermentation using controlled illumination

Abstract

Bioreactors and methods for cultivating microalgae are provided herein. The bioreactor and methods include features and modifications to improve heterotrophic growth efficiency by providing a light signal.

What is claimed is: 
     
         1 . A method for cultivating a microalgae comprising a photoreceptor sensitive to a particular region of a visible spectrum under a heterotrophic growth condition, comprising:
 incubating the microalgae under the heterotrophic growth condition for a period of time sufficient to allow the microalgae to grow,   wherein the heterotrophic growth condition comprises:   a media comprising a carbon source, and   an irradiance of light including the particular region of the visible spectrum in a sufficient intensity to transduce the photoreceptor.   
     
     
         2 . The method of  claim 1 , wherein the microalgae is a  Botryococcus  strain, wherein the carbon source is glucose, and wherein the irradiance of light is between 1-10 μmol photons m −2 s −1 . 
     
     
         3 . The method of  claim 1 , wherein the microalgae is a  Botryococcus sudeticus  strain, a  Botryococcus  strain, a UTEX 2629 strain, a  Botryococcus braunii  strain, a UTEX 2441 strain, a  Neochloris oleabundans  strain, a  Neochloris  strain, a UTEX 1185 strain, a  Chlamydomonas reinhardtii  strain, a  Chlamydomonas  strain, a UTEX 2243 strain, or a strain comprising a photoreceptor. 
     
     
         4 . The method of  claim 2 , wherein the microalgae is a UTEX 2629 strain or a UTEX 2441 strain. 
     
     
         5 . The method of  claim 1 , wherein the carbon source is glucose. 
     
     
         6 . The method of  claim 1 , wherein the carbon source is selected from the group consisting of a fixed carbon source, glucose, fructose, sucrose, galactose, xylose, mannose, rhamnose, N-acetylglucosamine, glycerol, floridoside, glucuronic acid, corn starch, depolymerized cellulosic material, sugar cane, sugar beet, lactose, milk whey, and molasses. 
     
     
         7 . The method of  claim 1 , wherein the light is produced by an artificial light source, or the light is artificial light. 
     
     
         8 . The method of  claim 1 , wherein the intensity of the irradiance of light is between 0.01-1 μmol photons m −2 s −1 , between 1-10 μmol photons m −2 s −1 , between 10-100 μmol photons m −2 s −1 , between 100-300 μmol photons m −2 s −1 , 3-4 μmol/m 2 s −1  photons, 2-3 μmol/m 2 s −1  photons, 1-2 μmol/m 2 s −1  photons, or 3-5 μmol/m 2 s −1  photons. 
     
     
         9 . The method of  claim 1 , further comprising producing a material from the microalgae. 
     
     
         10 . The method of  claim 9 , wherein the material is a polysaccharide, a pigment, a lipid, or a hydrocarbon. 
     
     
         11 . The method of  claim 9 , wherein the material is a hydrocarbon. 
     
     
         12 . The method of  claim 9 , further comprising recovering the material. 
     
     
         13 . The method of  claim 9 , further comprising extracting the material. 
     
     
         14 . The method of  claim 9 , further comprising processing the material. 
     
     
         15 . The method of  claim 12 , further comprising processing the material. 
     
     
         16 . The method of  claim 14 , wherein the processing of the material produces a processed material. 
     
     
         17 . The method of  claim 16 , wherein the processed material is selected from the group consisting of a fuel, biodiesel, jet fuel, a cosmetic, a pharmaceutical agent, a surfactant, and a renewable diesel. 
     
     
         18 . A method of manufacturing a material, comprising:
 providing a microalgae comprising a photoreceptor sensitive to a particular region of a visible spectrum and capable of producing the material;   culturing the microalgae in a media, wherein the media comprises a carbon source;   applying an irradiance of light including the particular region of the visible spectrum in a sufficient intensity to transduce the photoreceptor; and   allowing the microalgae to accumulate at least 10% of its dry cell weight as the material.   
     
     
         19 . A bioreactor system, comprising:
 a bioreactor;   a culture medium comprising a carbon source, wherein the culture medium is located inside the bioreactor;   a microalgae comprising a photoreceptor sensitive to a particular region of a visible spectrum and adapted for heterotrophic growth, wherein the microalgae is located in the culture media; and   a light source, wherein the light source produces an irradiance of light including the particular region of the visible spectrum in a sufficient intensity to transduce the photoreceptor,   and wherein the light source is operatively coupled to the bioreactor.