Processes of producing ethanol using a fermenting organism
The invention relates to improved processes of producing ethanol from starch-containing material wherein saccharification and/or fermentation is done at a temperature below the initial gelatinization temperature in the presence of glucoamylase and alpha-amylase, and optionally a protease and/or a cellulolytic enzyme composition; wherein the fermenting organism is a Saccharomyces yeast strain providing a higher ethanol yield boost and lower glycerol production compared to ETHANOL RED™ under the same fermentation conditions. The invention also relates to Saccharomyces yeast strains and derivatives thereof, as well as compositions comprising such yeast strains, suitable for use in a process of the invention.
1. A process of producing ethanol from starch-containing material, the process comprising:
(a) saccharifying starch-containing material at a temperature below the initial gelatinization temperature; and
(b) fermenting using a fermentation organism;
wherein saccharification and/or fermentation is done in the presence of a glucoamylase and an alpha-amylase;
wherein the fermenting organism is:
Saccharomyces cerevisiae MBG4911 (deposited as V15/001459 at National Measurement Institute, Victoria, Australia);
Saccharomyces cerevisiae MBG4913 (deposited as V15/001460 at National Measurement Institute, Victoria, Australia); or
Saccharomyces cerevisiae MBG4914 (deposited as V15/001461 at National Measurement Institute, Victoria, Australia).
2. The process of claim 1 , wherein the fermenting organism is capable of growing on xylose as a sole carbon source.
3. The process of claim 1 , wherein the fermenting organism provides an ethanol yield boost of at least 0.5% after 88 hours compared to the ETHANOL RED™ Saccharomyces cerevisiae strain deposited as V14/007039 at National Measurement Institute, Victoria, Australia under the same conditions.
4. The process of claim 1 , wherein the fermenting organism provides a lower glycerol production of at least 5% after 88 hours compared to the ETHANOL RED™ Saccharomyces cerevisiae strain deposited as V14/007039 at National Measurement Institute, Victoria, Australia under the same conditions.
5. A Saccharomyces yeast strain selected from:
Saccharomyces cerevisiae MBG4911 (deposited as V15/001459 at National Measurement Institute, Victoria, Australia);
Saccharomyces cerevisiae MBG4913 (deposited as V15/001460 at National Measurement Institute, Victoria, Australia); and
Saccharomyces cerevisiae MBG4914 (deposited as V15/001461 at National Measurement Institute, Victoria, Australia).
6. The yeast strain of claim 5 , wherein the strain is capable of growing on xylose as a sole carbon source.
7. The yeast strain of claim 5 , wherein the strain is capable of providing an ethanol yield boost of at least 0.5% after 88 hours compared to the ETHANOL RED™ Saccharomyces cerevisiae strain deposited as V14/007039 at National Measurement Institute, Victoria, Australia under the same conditions.
8. The yeast strain of claim 5 , wherein the strain is capable of providing a lower glycerol production of at least 5% after 88 hours compared to the ETHANOL RED™ Saccharomyces cerevisiae strain deposited as V14/007039 at National Measurement Institute, Victoria, Australia under the same conditions.
9. A method of producing a derivative of strain Saccharomyces cerevisiae MBG4911, MBG4913 or MBG4914, the method comprising:
(a) providing:
(i) a first yeast strain; and
(ii) a second yeast strain, wherein the second yeast strain is strain Saccharomyces cerevisiae MBG4911, MBG4913 or MBG4914;
(b) culturing the first yeast strain and the second yeast strain under conditions which permit combining of DNA between the first and second yeast strains;
(c) screening or selecting for a derivative strain.
10. The method of claim 9 , wherein step (c) comprises screening or selecting for a hybrid strain which exhibits one or more defining characteristic of strain Saccharomyces cerevisiae MBG4911, MBG4913 or MBG4914.
11. The method of claim 9 , comprising the further step of:
(d) repeating steps (b) and (c) with the screened or selected strain from step (c) as the first and/or second strain, until a derivative is obtained which exhibits the defining characteristics of strain Saccharomyces cerevisiae MBG4911, MBG4913 or MBG4914.
12. The method of claim 9 , wherein the culturing step (b) comprises:
(i) sporulating the first yeast strain and the second yeast strain;
(ii) hybridizing germinated spores produced by the first yeast strain with germinated spores produced by the second yeast strain.
13. A method of producing ethanol, comprising incubating the Saccharomyces yeast strain of claim 5 with a substrate comprising a fermentable sugar under conditions which permit fermentation of the fermentable sugar to produce ethanol.
14. A composition comprising a Saccharomyces yeast strain of claim 5 and one or more components selected from surfactants, emulsifiers, gums, swelling agents, and antioxidants.
15. A method of producing a recombinant derivative of the Saccharomyces yeast of claim 5 , the method comprising introducing a nucleic acid into the Saccharomyces yeast of claim 5 using recombinant DNA technology.
16. The method of claim 15 , wherein the nucleic acid is introduced into Saccharomyces cerevisiae MBG4911 (deposited as V15/001459 at National Measurement Institute, Victoria, Australia).