Process for fermenting sugars containing oligomeric saccharides

• US 9,328,364 B2
• Filed: 03/16/2005
• Issued: 05/03/2016
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Cargill, Inc. (Agricultural Services Division)
• Original Assignee: Cargill, Inc. (Agricultural Services Division)
• Inventors: Beacom, Daniel R., Kolstad, Jeffrey J., Reeder, David H., Rush, Brian J.
• Primary Examiner(s): Afremova, Vera
• Application Number:
  US11/547,211
• Publication Number:
  US 20090011481A1
• Time in Patent Office: 4,066 Days
• Field of Search: None
• US Class Current: 1/1
• 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 depolymerize the oligomers simultaneously with the fermentation process.

Claims

1. A process for fermenting a starch hydrolysate containing 80-98 weight percent of glucose and 1-9 weight percent of nonfermentable glucose oligomers having a degree of polymerization from 2 to 10, which nonfermentable glucose oligomers include isomaltose, comprising forming a fermentation broth containing the starch hydrolysate and having a glucose concentration of at least 50 g/L, fermenting the starch hydrolysate in the presence of a microorganism that ferments the glucose to a desired fermentation product and in the absence of an enzyme that is capable of depolymerizing the nonfermentable glucose oligomer(s) until the fermentation broth contains 26 g/L or less of glucose and from about 1 to about 10 g/L of one or more nonfermentable glucose oligomers, then adding 5-10,000 μ

L of trans-glucosidase per liter of fermentation broth, and then subjecting the fermentation broth to fermentation conditions in the presence of (A) a microorganism that ferments glucose but does not ferment said nonfermentable glucose oligomers and (B) said trans-glucosidase, under conditions such that the depolymerization of the isomaltose and the fermentation of the glucose occur simultaneously.

2. The process of claim 1 wherein the microorganism ferments the glucose to lactic acid.

3. The process of claim 1, wherein the glucose oligomers have a degree of polymerization of from 2 to 5.

4. The process of claim 3 wherein the microorganism ferments the glucose to lactic acid.