Supplementation of fatty acids for improving alcohol productivity

Abstract

Fatty acids derived from biomass at a step in a fermentation process can be added to a fermentation medium comprising a recombinant microorganism that produces a product alcohol. At least one of growth rate and fermentable carbon consumption of the microorganism is greater in the presence of the fatty acids than the growth rate and the fermentable carbon consumption of the microorganism in the absence of the fatty acids. The addition of the fatty acids can increase glucose consumption, and can improve microorganism biomass production (cell growth/density) and growth rate, thereby reducing production time and increasing productivity of the fermentation process.

1 - 8 . (canceled) 
     
     
         9 . A method for producing a product alcohol comprising:
 (a) providing biomass comprising a fermentable carbon source and oil;   (b) converting at least a portion of the oil into fatty acids to form a biomass comprising the fatty acids;   (c) contacting the biomass with a fermentation broth comprising a recombinant microorganism capable of producing a product alcohol from a fermentable carbon source, and wherein the recombinant microorganism comprises a reduction or elimination of pyruvate decarboxylase activity;   (d) contacting the fatty acids with the fermentation broth,   wherein at least one of (i) growth rate and (ii) fermentable carbon consumption of the recombinant microorganism is greater in the presence of the fatty acids than the growth rate and/or the fermentable carbon consumption of the recombinant microorganism is in the absence of the fatty acids.   
     
     
         10 . The method of  claim 9 , wherein the step (b) of converting at least a portion of the oil into fatty acids comprises contacting the oil with one or more substances capable of hydrolyzing the portion of the oil into fatty acids. 
     
     
         11 . The method of  claim 10 , wherein the one or more substances comprise one or more enzymes. 
     
     
         12 . The method of  claim 11 , wherein the one or more enzymes comprise lipase enzymes. 
     
     
         13 . The method of  claim 11 , further comprising:
 prior to step (c), inactivating the one or more enzymes after at least a portion of the oil is hydrolyzed.   
     
     
         14 . The method of  claim 9 , wherein one or more of steps (b), (c), and (d) occurs in the fermentation vessel. 
     
     
         15 . The method of  claim 9 , wherein one or more of steps (b), (c), and (d) occurs substantially simultaneously. 
     
     
         16 . The method of  claim 9 , wherein biomass is derived from corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, rye, wheat straw, barley, barley straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum, sugar cane, soy, components obtained from milling of grains, cellulosic material, lignocellulosic material, trees, branches, roots, leaves, wood chips, sawdust, shrubs and bushes, vegetables, fruits, flowers, animal manure, and mixtures thereof. 
     
     
         17 . The method of  claim 9 , wherein the fatty acids are selected from oleic acid, palmitic acid, myristic acid, and mixtures thereof. 
     
     
         18 . The method of  claim 9 , further comprising fermenting the fermentable carbon source to produce product alcohol. 
     
     
         19 . The method of  claim 18 , wherein the product alcohol is butanol. 
     
     
         20 . The method of  claim 9 , wherein the fermentation broth further comprises ethanol. 
     
     
         21 . The method of  claim 9 , wherein the recombinant microorganism has a one or more pyruvate decarboxylase (PDC) gene deletions. 
     
     
         22 . The method of  claim 9 , further comprising:
 separating the oil from the biomass prior to the step (b) of converting at least a portion of the oil into fatty acids.   
     
     
         23 . The method of  claim 9 , further comprising:
 liquefying the biomass to produce a liquefied biomass, wherein the liquefied biomass comprises oligosaccharides; and   contacting the liquefied biomass with a saccharification enzyme capable of converting oligosaccharides into fermentable sugar to form a saccharified biomass,   and wherein step (c) comprises contacting the saccharified biomass with the fermentation broth comprising a recombinant microorganism.   
     
     
         24 . A method for producing a product alcohol comprising:
 (a) providing a feedstock;   (b) liquefying said feedstock to create a feedstock slurry;   (c) separating the feedstock slurry to produce a product comprising (i) an aqueous layer comprising a fermentable carbon source, (ii) an oil layer, and (iii) a solids layer;   (d) obtaining an oil from the oil layer and converting at least a portion of the oil into fatty acids;   (e) feeding the aqueous layer of (c) to a fermentation vessel containing a fermentation broth comprising a recombinant microorganism capable of producing a product alcohol from a fermentable carbon source, wherein the recombinant microorganism comprises a reduction or elimination of pyruvate decarboxylase activity;   (f) fermenting the fermentable carbon source of the aqueous layer to produce the product alcohol; and   (g) contacting the fermentation broth with the fatty acids, wherein at least one of (i) growth rate and (ii) fermentable carbon consumption of the recombinant microorganism is greater in the presence of the fatty acids than the growth rate and/or the fermentable carbon consumption of the recombinant microorganism is in the absence of the fatty acids.   
     
     
         25 . The method of  claim 24 , wherein the step (d) of converting at least a portion of the oil into fatty acids comprises contacting the oil with one or more substances capable of hydrolyzing the portion of the oil into fatty acids. 
     
     
         26 . The method of  claim 25 , wherein the one or more substances comprises one or more enzymes. 
     
     
         27 . The method of  claim 26 , wherein the one or more enzymes comprises lipase enzymes. 
     
     
         28 . The method of  claim 24 , wherein feedstock comprises one or more fermentable sugars derived from corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, rye, wheat straw, barley, barley straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum, sugar cane, soy, components obtained from milling of grains, cellulosic material, lignocellulosic material, trees, branches, roots, leaves, wood chips, sawdust, shrubs and bushes, vegetables, fruits, flowers, animal manure, and mixtures thereof. 
     
     
         29 . The method of  claim 24 , wherein the fatty acids are selected from oleic acid, palmitic acid, myristic acid, and mixtures thereof. 
     
     
         30 . The method of  claim 18 , wherein the product alcohol is butanol. 
     
     
         31 . The method of  claim 24 , wherein the recombinant microorganism has a one or more pyruvate decarboxylase (PDC) gene deletions. 
     
     
         32 . (canceled)