Systems and Methods for Producing Biofuels and Related Materials
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.