Abstract:
The present invention is directed to a. yeast strain, or strains, secreting a full suite, or any subset of that, full suite, of enzymes to hydrolyze com starch, corn fiber, lignocellulose, (including enzymes that hydrolyze linkages in cellulose, hemicelhiiose, and between lignin and carbohydrates) and to utilize pentose sugars (xylose and arabinose). The invention is also directed to the set of proteins that are well expressed in yeast for each category of enzymatic activity. The resulting strain, or strains can be used to hydrolyze starch and cellulose simultaneously. The resulting strain, or strains can be also metabolically engineered to produce less glycerol and uptake acetate. The resulting strain, or strains can also be used to produce ethanol from granular starch without liquefaction. The resulting strain, or strains, can be further used to reduce the amount of external enzyme needed to hydrolyze a biomass feedstock during an Simultaneous Saccharification and Fermentation (SSF) process, or to increase the yield of ethanol during SSF at current saccharolytic enzyme loadings. In addition, multiple enzymes of the present invention can be co-expressed in cells of the invention to provide synergistic digestive action on biomass feedstock. In some aspects, host cells expressing different heterologous saccharolytic enzymes can also be co-cultured togetherand used to produce ethanol from biomass feedstock.
Abstract:
A process and system for producing a fermentation product, such as ethanol, includes introducing biomass and a microorganism into a mixing tank, mixing the biomass and microorganism in the mixing tank to form a slurry, pumping the slurry to a cone bottom fermenter, and allowing the microorganism to ferment the biomass into a fermentation product. The cone bottom fermenter can have a cone-shaped bottom having an angle in a range from above 45 degrees to about 80 degrees.
Abstract:
The present invention is directed to a. yeast strain, or strains, secreting a full suite, or any subset of that, full suite, of enzymes to hydrolyze com starch, corn fiber, lignocellulose, (including enzymes that hydrolyze linkages in cellulose, hemicelhiiose, and between lignin and carbohydrates) and to utilize pentose sugars (xylose and arabinose). The invention is also directed to the set of proteins that are well expressed in yeast for each category of enzymatic activity. The resulting strain, or strains can be used to hydrolyze starch and cellulose simultaneously. The resulting strain, or strains can be also metabolically engineered to produce less glycerol and uptake acetate. The resulting strain, or strains can also be used to produce ethanol from granular starch without liquefaction. The resulting strain, or strains, can be further used to reduce the amount of external enzyme needed to hydrolyze a biomass feedstock during an Simultaneous Saccharification and Fermentation (SSF) process, or to increase the yield of ethanol during SSF at current saccharolytic enzyme loadings. In addition, multiple enzymes of the present invention can be co-expressed in cells of the invention to provide synergistic digestive action on biomass feedstock. In some aspects, host cells expressing different heterologous saccharolytic enzymes can also be co-cultured togetherand used to produce ethanol from biomass feedstock.