Systems and Methods for Producing Biofuels and Related Materials

Abstract

Clostridium phytofermentans cells (American Type Culture Collection 700394 T ) and all other strains of the species can ferment materials such as biomass into useful products and coproducts, such as ethanol, hydrogen and organic acids. Compositions that include Clostridium phytofermentans are also disclosed.

1 . An isolated organism that ferments a saccharification product of a cellulolytic substrate to produce ethanol in a concentration that is at least about 90% of a theoretical yield, wherein the organism does not express pyruvate decarboxylase. 
     
     
         2 . An isolated organism of  claim 1 , wherein said organism is transformed or genetically modified. 
     
     
         3 . An isolated organism of  claim 1 , wherein the organism is a bacteria or yeast. 
     
     
         4 . An isolated organism of  claim 1 , wherein the bacteria is  Clostridium phytofermentans.    
     
     
         5 . A composition comprising an isolated organism of  claim 1  and  Zymomona mobilis.    
     
     
         6 . A method for producing ethanol, the method comprising:
 transforming a native organism that ferments a saccharification product of a cellulolytic substrate to produce ethanol in a concentration that is at least about 90% of a theoretical yield, wherein the organism does not express pyruvate decarboxylase to produce a transformed organism; and   culturing the transformed organism in a medium that contains a substrate including a material selected from the group consisting of glucose, xylose, mannose, arabinose, galactose, fructose, cellobiose, sucrose, maltose, xylan, mannan, starch, and combinations thereof under suitable conditions for a period of time sufficient to allow saccharification and fermentation of the substrate.   
     
     
         7 . The method of  claim 6 , wherein the cellulolytic substrate is hydrolyzed. 
     
     
         8 . The method of  claim 7 , wherein the hydrolysis step comprises treatment with an acid, treatment with one or more enzymes, or treatment with acid followed by de-watering. 
     
     
         9 . The method of  claim 6 , wherein the organism is a bacteria or yeast. 
     
     
         10 . The method of  claim 6 , wherein the bacteria is  Clostridium phytofermentans.    
     
     
         11 . The method of  claim 6 , further comprising culturing  Zymomona mobilis  in the medium.