초록 ▼

The present invention provides means for the production of desired end-products of in vitro and/or in vivo bioconversion of biomass-based feed stock substrates, including but not limited to such materials as starch and cellulose. In particularly preferred embodiments, the methods of the present inve

The present invention provides means for the production of desired end-products of in vitro and/or in vivo bioconversion of biomass-based feed stock substrates, including but not limited to such materials as starch and cellulose. In particularly preferred embodiments, the methods of the present invention do not require gelatinization and/or liquefaction of the substrate. In particularly preferred embodiments, the present invention provides means for the production of ethanol.

대표청구항 ▼

1. A method for producing ethanol as an end-product comprising the steps of: a) contacting a substrate comprising a ground corn slurry comprising uncooked starch with a substrate-converting enzyme and an intermediate-converting enzyme to produce an intermediate comprising glucose, wherein the substr

1. A method for producing ethanol as an end-product comprising the steps of: a) contacting a substrate comprising a ground corn slurry comprising uncooked starch with a substrate-converting enzyme and an intermediate-converting enzyme to produce an intermediate comprising glucose, wherein the substrate-converting enzyme and the intermediate-converting enzyme are both obtained from a microorganism of the genus Rhizopus and at least the substrate-converting enzyme is a raw starch hydrolyzing enzyme; andb) contacting the intermediate with an ethanologenic microorganism to produce ethanol, wherein at least 90% of the uncooked starch of the ground corn slurry is converted to the intermediate comprising glucose within 72 hours; and the glucose is converted to ethanol at a rate sufficient to maintain the concentration of the glucose at less than 0.25% by weight volume. 2. The method according to claim 1, wherein the substrate is sequentially contacted with the substrate-converting enzyme and then with the intermediate-converting enzyme. 3. The method according to claim 1, wherein the contacting step b) is conducted at a temperature of 25 to 35° C. 4. The method according to claim 1, wherein 72 hours after contacting the intermediate with the ethanologenic microorganism, the amount of ethanol produced is at least 14% after 72 hours. 5. The method according to claim 1, wherein the raw starch hydrolyzing enzyme comprises a glucoamylase which is added in the range of 0.05 to 10.0 glucoamylase units (GAU)/g of starch. 6. The method according to claim 1, wherein the ground corn slurry has a percentage of starch between about 10% and about 35%. 7. The method according to claim 1, wherein the raw starch hydrolyzing enzyme is secreted by a microorganism of the genus Rhizopus in contact with said uncooked starch. 8. The method according to claim 1, wherein the raw starch hydrolyzing enzyme is obtained from R. niveus. 9. The method according to claim 1, further comprising adding a glucoamylase derived from a microorganism of the genus Aspergillus to the contacting step a). 10. The method according to claim 1, further comprising adding an alpha amylase to the contacting step a). 11. The method according to claim 1, wherein the intermediate-converting enzyme is secreted by a microorganism of the genus Rhizopus in contact with said intermediate. 12. The method according to claim 1, wherein at least 95% of the uncooked starch is converted to the intermediate comprising glucose within 72 hours.