Methods and systems for propagation of a microorganism using a pulp mill and/or a paper mill waste by-product, and related methods and systems
The present disclosure relates to using a source of one or more monosaccharides derived from a pulp or paper mill waste by-product for propagating microorganisms (e.g., yeast or bacteria). If desired, after propagation, the microorganisms can then be used to ferment one or more monosaccharides derived from a pulp or paper mill waste by-product into one or more biochemicals. Optionally, a stillage composition can be included in propagation medium to facilitate propagation and/or a stillage composition can be used to facilitate enzymatic hydrolysis of oligosaccharides and/or polysaccharides in a pulp or paper mill waste by-product to form monosaccharides.
1. A method of propagating a microorganism, the method comprising:
a) combining at least one pulp or paper mill waste by-product and an ionic stabilizing component, wherein the at least one pulp or paper mill waste by-product is chosen from a pulp sludge, a paper sludge, and combinations thereof, wherein the ionic stabilizing component is chosen from one or more salts, at least one stillage composition, corn steep liquor, at least one pulp or paper mill waste by-product liquor, and combinations thereof, and wherein the at least one stillage composition is derived from a grain starch ethanol process,
b) enzymatically hydrolyzing one or more polysaccharides and/or one or more oligosaccharides present in at least one pulp or paper mill waste by-product in the presence of one or more enzymes and into one or more monosaccharides, wherein the one or more enzymes are chosen from one or more cellulase enzymes, one or more hemicellulose enzymes, and combinations thereof;
c) providing a first cell mass of a microorganism that can convert one or more monosaccharides into a biochemical via fermentation; and
d) propagating the first cell mass of the microorganism in a propagation composition that comprises one or more monosaccharides from the enzymatic hydrolysis as a carbon source to propagate the first cell mass of the microorganism into a second cell mass of the microorganism.
2. The method of claim 1 , wherein the enzymatic hydrolysis and the propagating occur simultaneously.
3. The method of claim 2 , wherein the propagation composition has a conductivity from 1 microSiemen/cm to 50 milliSiemens/cm.
4. The method of claim 2 , wherein the propagation composition has a conductivity from 40 microSiemens/cm to 40 milliSiemens/cm.
5. The method of claim 1 , wherein the enzymatic hydrolysis occurs before the propagating.
6. The method of claim 1 , wherein the ionic stabilizing component comprises at least one liquor derived from a sulphite pulping process.
7. The method of claim 6 , wherein the ionic stabilizing component further comprises at least one stillage composition chosen from thin stillage, condensed thin stillage, and combinations thereof.
8. The method of claim 1 , wherein the ionic stabilizing component comprises at least one stillage composition chosen from whole stillage, thin stillage, condensed thin stillage, wet cake, and combinations thereof.
9. The method of claim 8 , wherein a weight ratio of the at least one stillage composition to the at least one pulp or paper mill waste by-product is from 0.01 to 40 on a dry weight basis.
10. The method of claim 8 , wherein a weight ratio of the at least one stillage composition to the at least one pulp or paper mill waste by-product is from 1 to 30 on a dry weight basis.
11. The method of claim 1 , wherein the second cell mass of the microorganism is at least 200 times greater in number than the first cell mass of the microorganism.
12. The method of claim 1 , wherein the first cell mass of the microorganism is 5×10{circumflex over ( )}6 cells per milliliter of the propagation composition or less, and the second cell mass of the microorganism is 1×10{circumflex over ( )}8 cells per milliliter of the propagation composition or more.
13. The method of claim 1 , wherein the microorganism comprises an ethanologen.
14. The method of claim 13 , wherein the ethanologen comprises non-genetically modified Saccharomyces cerevisiae and/or Saccharomyces cerevisiae that has been genetically modified to convert xylose and glucose into ethanol.
15. The method of claim 1 , further comprising fermenting at least a portion of the second cell mass in the presence of one or more monosaccharides to convert the one or more monosaccharides into a biochemical.
16. The method of claim 1 , wherein the grain starch ethanol process comprises enzymatically hydrolyzing the grain starch with one or more amylase enzymes.
17. The method of claim 1 , wherein the pulp sludge and/or the paper sludge has been washed prior to the enzymatic hydrolysis.
18. The method of claim 1 , wherein the ionic stabilizing component comprises corn steep liquor.
19. A method of propagating a microorganism, the method comprising:
a) combining at least one pulp or paper mill waste by-product and an ionic stabilizing component, wherein the at least one pulp or paper mill waste by-product is chosen from a pulp sludge, a paper sludge, and combinations thereof, and wherein the ionic stabilizing component is chosen from one or more salts, corn steep liquor, at least one pulp or paper mill waste by-product liquor, and combinations thereof,
b) enzymatically hydrolyzing one or more polysaccharides and/or one or more oligosaccharides present in at least one pulp or paper mill waste by-product in the presence of one or more enzymes and into one or more monosaccharides, wherein the one or more enzymes are chosen from one or more cellulase enzymes, one or more hemicellulose enzymes, and combinations thereof;
c) providing a first cell mass of a microorganism that can convert one or more monosaccharides into a biochemical via fermentation; and
d) propagating the first cell mass of the microorganism in a propagation composition that comprises one or more monosaccharides from the enzymatic hydrolysis as a carbon source to propagate the first cell mass of the microorganism into a second cell mass of the microorganism.
20. The method of claim 19 , wherein the pulp sludge and/or the paper sludge has been washed prior to the enzymatic hydrolysis.