Process for fermenting sugars containing oligomeric saccharides

• US 9,714,438 B2
• Filed: 10/27/2014
• Issued: 07/25/2017
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Cargill Incorporated
• Original Assignee: Cargill Incorporated
• Inventors: Beacom, Daniel R., Kolstad, Jeffrey J., Reeder, David H., Rush, Brian J.
• Primary Examiner(s): Afremova, Vera
• Application Number:
  US14/524,032
• Publication Number:
  US 20150132814A1
• Time in Patent Office: 1,002 Days
• Field of Search: None
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/04 Polysaccharides, i.e. compounds containing more than five saccharide radicals attached to each other by glycosidic bonds
• CPC Class Codes: C12P 19/16 produced by the action of an alpha-1, 6-glucosidase, e.g. amylose, debranched amylopectin non-biological hydrolysis of starch C08B30/00
• CPC Class Codes: C12P 19/20 produced by the action of an exo-1,4 alpha-glucosidase, e.g. dextrose
• CPC Class Codes: C12P 7/56 Lactic acid

Abstract

Sugar mixtures containing nonfermentable oligomers are fermented in the presence of certain enzymes that depolymerise the oligomers simultaneously with the fermentation process.

Claims

1. A fermentation process comprising subjecting a fermentation broth containing 30 g/L or less of a monosaccharide and from about 1 to about 25 g/L of isomaltose to fermentation conditions in the presence of (A) a microorganism that ferments the monosaccharide but does not ferment isomaltose or ferments isomaltose at a rate not more than 5% of the rate at which the microorganism ferments the monosaccharide under the conditions used in the process and (B) an effective amount of trans-glucosidase, under conditions such that the depolymerization of the isomaltose and the fermentation of the monosaccharides occur simultaneously.

2. The fermentation process of claim 1, wherein the monosaccharide is glucose.

3. The fermentation process of claim 1, wherein the microorganism is a yeast.

4. The fermentation process of claim 3, wherein the yeast is selected from a yeast strain of the genera Kluyveromyces, Pichia, Hansenula, Trichosporon, or Yamadazyma.

5. The fermentation process of claim 1, wherein the microorganism is a bacillus or lactobacillus.

6. The fermentation process of claim 1, wherein the microorganism is a wild-type bacteria from the genera Lactobacillus, Pediococcus, Lactococcus or Streptococcus.

7. The fermentation process of claim 1 that includes the steps of:

A) forming a starting fermentation broth containing (1) a fermentation substrate containing 80-98 weight-% of a monosaccharide based on carbohydrates and 1-20 weight percent isomaltose, wherein the starting fermentation broth contains at least 50 g/L of the monosaccharide;

B) fermenting the starting fermentation broth in the presence of the microorganism under conditions sufficient to ferment the monosaccharide and reduce the monosaccharide concentration in the fermentation broth to less than about 30 g/L;

C) then adding to the fermentation broth the effective quantity of trans-glucosidase;

D) and then subjecting the fermentation broth to conditions sufficient to simultaneously depolymerize the isomaltose and ferment the monosaccharide to form the fermentation product.