Sugar transporter-modified yeast strains and methods for bioproduct production
AssigneeCargill, Incorporated
InventorsChristopher K. Miller, Ana Negrete-Raymond, Brian J. Rush, Amit Vas, Jon Veldhouse
Life of this patent
Estimating the term…
Abstract
Genetically modified yeast having a heterologous sugar transporter that is capable of transporting a non-glucose sugar such as maltulose, are described. The heterologous sugar transporter can be a protein according to, or that has similarity to, SEQ ID NO: 44. Fermentation methods using enzymatically treated starch where the yeast are able to consume the non-glucose sugars, are also described. The engineered yeast can be useful for producing desired bioproducts such as high ethanol, with low amounts of residual sugars in the medium.
Claims17
A fermentation method comprising:
- providing a fermentation medium comprising a hydrolyzed starch composition comprising maltulose and an engineered yeast comprising a gene encoding a heterologous di- or tri-glucopyranosyl sugar transporter polypeptide with an amino acid sequence at least 90% identical to SEQ ID NO:44, wherein maltulose is present at a first concentration of 0.5 g/L or greater at a first time point;
- and
- fermenting the fermentable carbohydrate composition in the medium over a period of time to a second time point wherein maltulose is present in the medium at a second concentration, and the second concentration is less than a concentration of maltulose obtained using an otherwise identical yeast that does not have the heterologous sugar transporter at the second time point under the same fermentation conditions.
A genetically modified yeast comprising a gene encoding a heterologous di- or tri-glucopyranosyl sugar transporter polypeptide with an amino acid sequence at least 90% identical to SEQ ID NO:44, wherein the yeast is capable of growing at a rate of 0.02 or greater on synthetic media comprising a carbohydrate composition wherein maltulose is present in an amount of at least 97% (wt) in the carbohydrate composition, grown under standard conditions.
Dependencies are inferred from the claim text.