Fermentation process using yeast cells having disrupted pathway from dihydroxyacetone phosphate to glycerol

{
  "publication_number": "US10899544B2",
  "country": "US",
  "kind": "B2",
  "title": "Fermentation process using yeast cells having disrupted pathway from dihydroxyacetone phosphate to glycerol",
  "abstract": "Yeast cells are genetically modified to disrupt a native metabolic pathway from dihydroxyacetone to glycerol. In certain aspects, the yeast cell is of the genera Kluyveromyces, Candida or Issatchenkia. In other aspects, the yeast cell is capable of producing at least one organic acid, such as lactate. The yeast cells produce significantly less glycerol than the wild-type strains, and usually produce greater yields of desired fermentation products. Yeast cells of the invention often grow well when cultivated, despite their curtailed glycerol production.",
  "claims": [
    "1. A fermentation process wherein a cell is cultivated in a fermentation medium under fermentation conditions and in the presence of a carbon source and added glycerol to produce an organic acid or ethanol, wherein the glycerol yield is less than 2% based on the weight of the carbon source that is consumed by the cell, wherein the cell is a yeast cell selected from the group consisting of Issatchenkia orientalis, Pichia galeiformis, Pichia sp. YB-4149 (NRRL designation), Candida ethanolica, P. deserticola, P. membranifaciens, P. fermentans, S. kluyveri, K. aestuaryii, K. nonfermentans, K. lactic, K. marxianus and K. dobzhanskii, in which the entire coding region of at least one native glycerol-3-phosphate dehydrogenase gene has been eliminated or the coding region, promoter or terminator region of at least one native glycerol-3-phosphate dehydrogenase gene has been modified by deletion or insertion so the native glycerol-3-phosphate dehydrogenase gene no longer produces an active glycerol-3-phosphate dehydrogenase enzyme.",
    "2. The fermentation process of claim 1 wherein the organic acid or ethanol is produced in a yield of at least 40% based on the weight of the carbon source that is consumed by the cell.",
    "3. The process of claim 2, wherein the glycerol yield is less than 0.5% based on the weight of the carbon source that is consumed by the cell.",
    "4. The process of claim 3, wherein ethanol is produced in the fermentation process.",
    "5. The fermentation process of claim 1 wherein an organic acid is produced in the fermentation process in a yield of at least 40% based on the weight of the carbon source that is consumed by the cell and the glycerol yield is less than 0.5% based on the weight of the carbon source that is consumed by the cell.",
    "6. The fermentation process of claim 1, wherein the cell is Issatchenkia orientalis.",
    "7. The fermentation process of claim 1, wherein the cell is Kluyveromyces marxianus.",
    "8. The fermentation process of claim 5, wherein the cell is Kluyveromyces marxianus or Issatchenkia orientalis.",
    "9. A fermentation process wherein a yeast cell is cultivated in a fermentation medium under fermentation conditions and in the presence of a carbon source and added glycerol to produce an organic acid, wherein the glycerol yield is less than 2% based on the weight of the carbon source that is consumed by the cell, wherein the yeast cell is selected from a species of the group consisting of Issatchenkia orientalis, Pichia galeiformis, Pichia sp. YB-4149 (NRRL designation), Candida ethanolica, P. deserticola, P. membranifaciens, P. fermentans, S. kluyveri, K. aestuaryii, K. nonfermentans, K. lactic, K. marxianus and K. dobzhanskii, and the yeast cell has a deletion or disruption of a native metabolic pathway from dihydroxyacetone phosphate to glycerol, wherein the deletion or disruption of the native metabolic pathway includes (i) a deletion or disruption of at least one native glycerol-3-phophate dehydrogenase; (ii) a deletion or disruption of at least one native glycerol-3-phosphatase gene; (iii) a deletion or disruption of at least one native glycerol-3-phosphate dehydrogenase gene and of at least one native glycerol-3-phosphatase gene; (iv) a deletion or disruption of at least one native dihydroxyacetone phosphatase gene; or (v) a deletion or disruption of both a native dihydroxyacetone phosphatase gene and a native glycerol-3-phosphate dehydrogenase gene; wherein the yeast cell produces an organic acid."
  ],
  "description_excerpt": "This application claims priority from U.S. Provisional Application No. 60/781,674, filed 13 Mar. 2006.\n\nThis invention was made under contract no. DE-FC36-03GO13145 with the United States Department of Energy. The United States Government has certain rights to this invention.\n\nThis invention relates to certain genetically modified yeast, and fermentation processes to produce lactic acid using those genetically modified yeast.\n\nYeast are used as biocatalysts in a number of industrial fermentations. There is an increasing interest in using yeast to ferment sugars to organic acids such as lactic acid. As more organic acid is produced in these fermentations, the fermentation medium becomes increasingly acidic. Most bacteria that produce these organic acids do not perform well in strongly acidic environments - they either do not survive under those conditions or else produce so slowly that the process becomes economically unviable. As a result, it becomes necessary to buffer the medium to maintain a higher pH. This causes difficulty in recovering the product in acid form. It is preferred to conduct the fermentation at a lower pH at which the product is partially or wholly in the acid form.\n\nYeast species have been considered as candidates for such low-pH fermentations. Many yeast species naturally ferment hexose sugars to ethanol, but few if any naturally produce significant yields of organic acids such as lactic acid. Accordingly, efforts have been made to genetically modify various yeast species to insert one or more genes that will enable the cell to produce lactic acid.",
  "cpc": [
    "B65G 15/12",
    "B65G 17/12",
    "C12N 15/52",
    "C12P 7/06",
    "C12P 7/40",
    "C12P 7/56",
    "E01B 29/32",
    "Y02E 50/10",
    "Y10T 137/85986"
  ],
  "ipc": [
    "B65G 15/12",
    "B65G 17/12",
    "C12N 15/52",
    "C12P 7/06",
    "C12P 7/40",
    "C12P 7/56",
    "E01B 29/32"
  ],
  "assignees": [
    "Cargill Inc"
  ],
  "inventors": [
    "Catherine Asleson Dundon",
    "Pirrko Suominen",
    "Aristos Aristidou",
    "Brian J. Rush",
    "Kari Koivuranta",
    "Benjamin Matthew Hause",
    "Thomas William McMullin",
    "Kevin Roberg-Perez"
  ],
  "filing_date": "2018-03-30",
  "publication_date": "2021-01-26",
  "grant_date": "2021-01-26",
  "priority_date": "2006-03-13",
  "application_number": "US-201815941274-A",
  "family_id": "38510074",
  "cited_by_count": 0,
  "citations": [
    "WO2006030799A1",
    "US20070161098A1"
  ]
}