Engineered CO2-Fixing Chemotrophic Microorganisms Producing Carbon-Based Products and Methods of Using the Same

Abstract

Disclosed herein are microorganisms containing exogenous or heterologous nucleic acid sequences, wherein the microorganisms are capable of growing on gaseous carbon dioxide, gaseous hydrogen, syngas, or combinations thereof. In some embodiments the microorganisms are chemotrophic bacteria that produce or secrete at least 10% of lipid by weight. Also disclosed are methods of fixing gaseous carbon into organic carbon molecules useful for industrial processes. Also disclosed are methods of manufacturing chemicals or producing precursors to chemicals useful in jet fuel, diesel fuel, and biodiesel fuel. Exemplary chemicals or precursors to chemicals useful in fuel production are alkanes, alkenes, alkynes, fatty acid alcohols, fatty acid aldehydes, desaturated hydrocarbons, unsaturated fatty acids, hydroxyl acids, or diacids with carbon chains between six and thirty carbon atoms long. Also disclosed are microorganisms and methods using disclosed microorganisms for the production of butanediol and its chemical precursors in low-oxygen or anaerobic fermentation. Also disclosed are microorganisms and methods using disclosed microorganisms for generating hydroxylated fatty acids in microbes through the transfer of enzymes that are known to hydroxylate fatty acids in plants or microbes. Also disclosed are microorganisms and methods using disclosed microorganisms for the production of shorter-chain fatty acids in microbes through the introduction of exogenous fatty acyl-CoA binding proteins.

What is claimed is: 
     
         1 . A bacterial cell of the genus  Cupriavidus, Xanthobacter, Hydrogenobacter , or  Hydrogenovibrio  comprising at least a first exogenous nucleic acid sequence, wherein the cell converts gaseous CO 2  and/or gaseous H 2  and/or syngas into one or more lipids or hydrocarbons. 
     
     
         2 .- 99 . (canceled) 
     
     
         100 . The bacterial cell of  claim 1 , wherein the first exogenous nucleic acid sequence encodes a fatty acyl-CoA binding protein. 
     
     
         101 . The bacterial cell of  claim 100 , further comprising a second exogenous nucleic acid sequence encoding a thioesterase. 
     
     
         102 . The bacterial cell of  claim 1 , wherein the bacterial cell is a knallgas microorganism. 
     
     
         103 . The bacterial cell of  claim 1 , wherein the bacterial cell is a chemoautrophic microorganism. 
     
     
         104 . The bacterial cell of  claim 103 , wherein the bacterial cell is a hydrogen-oxidizing chemoautotroph. 
     
     
         105 . The bacterial cell of  claim 1 , wherein the bacterial cell is capable of growing on syngas as the sole energy and carbon source. 
     
     
         106 . The bacterial cell of  claim 1 , wherein the bacterial cell produces and/or secretes lipids in a quantity that is at least 10% of the dry cell mass. 
     
     
         107 . The bacterial cell of  claim 1 , wherein at least 50% of said one or more lipids or hydrocarbons comprise 6 to 30 carbon atoms. 
     
     
         108 . The bacterial cell of  claim 1 , wherein the bacterial cell is a  Cupriavidus necator  or  Cupriavidus metallidurans  cell. 
     
     
         109 . A method for producing lipids or hydrocarbons, said method comprising culturing a bacterial cell of the genus  Cupriavidus, Xanthobacter, Hydrogenobacter , and/or  Hydrogenovibrio  in a bioreactor or solution with a feedstock comprising syngas and/or gaseous CO 2  and/or a mixture comprising gaseous CO 2  and H 2 ,
 wherein the bacterial cell comprises at least a first exogenous nucleic acid sequence, and   wherein said bacterial cell converts said feedstock into one or more lipids or hydrocarbons.   
     
     
         110 . The method of  claim 109 , wherein the first exogenous nucleic acid sequence encodes a fatty acyl-CoA binding protein. 
     
     
         111 . The method of  claim 110 , further comprising a second exogenous nucleic acid sequence encoding a thioesterase. 
     
     
         112 . The method of  claim 109 , wherein the bacterial cell is a knallgas microorganism. 
     
     
         113 . The method of  claim 109  wherein the bacterial cell is a chemoautrophic microorganism. 
     
     
         114 . The method of  claim 113 , wherein the bacterial cell is a hydrogen-oxidizing chemoautotroph. 
     
     
         115 . The method of  109 , wherein said feedstock comprises syngas as the sole energy and carbon source. 
     
     
         116 . The method of  claim 109 , wherein said one or more lipids or hydrocarbons are separated from the bioreactor or solution. 
     
     
         117 . The method of  claim 109  further comprising up-regulating an endogenous or exogenous thioesterase gene of the bacterial cell. 
     
     
         118 . The method of  claim 109 , further comprising down-regulating an endogenous or exogenous thioesterase gene of the bacterial cell. 
     
     
         119 . The method of  claim 109 , further comprising down-regulating an endogenous or exogenous acyl carrier protein gene of the bacterial cell. 
     
     
         120 . The method of  claim 109 , wherein the bacterial cell produces and/or secretes said lipids in a quantity that is at least 10% of the dry cell mass. 
     
     
         121 . The method of  claim 109  wherein the bacterial cell comprises  Cupriavidus necator  and/or  Cupriavidus metallidurans.