Cargill Inc.

Jon Veldhouse

Christopher K Miller

Brian Jeffrey Rush

Ana Negrete-Raymond

Amit Vas

Gregory Michael Poynter

Arlene M Fosmer

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.

Sugar transporter-modified yeast strains and methods for bioproduct production

The present invention relates to genetically modified yeasts that can use lactate as a carbon source to produce a fermentation product. In one aspect, the yeasts can consume glucose and lactate simultaneously to produce ethanol. In one aspect, the genetically modified yeast is transformed to include a monocarboxylic/monocarboxylate transporter. In one aspect, the yeast can include one or more heterologous genes encoding lactate dehydrogenase (cytochrome) (EC 1.1.2.3 and/or 1.1.2.4).

Genetically modified lactate-consuming yeasts and fermentation processes using such genetically modified yeasts

The present invention relates to genetically modified yeasts that can use lactate as a carbon source to produce a fermentation product. In one aspect, the yeasts can consume gluconse and lactate simultaneously to produce ethanol. In one aspect, the genetically modified yeast is transformed to include a monocarboxylic/monocarboxylate transporter. In one aspect, the yeast can include one or more heterologous genes encoding lactate dehydrogenase (cytochrome) (EC 1.1.2.3 and/or 1.1.2.4).

The invention is directed to non-natural yeast able to secrete significant amounts of glucoamylase into a fermentation media. The glucoamylase can promote degradation of starch material generating glucose for fermentation to a desired bioproduct, such as ethanol. The glucoamylase can be provided in the form of a glucoamylase fusion protein having amating factor alpha 2 (Sc MF&#x3b1;2) or repressible acid phosphatase (Sc PHO5) secretion signal.

Modified glucoamylase enzymes and yeast strains having enhanced bioproduct production

Genetically engineered yeast with a heterologous glucoamylase and fermentation methods are described. The engineered yeast can have multiple exogenous nucleic acid sequences which each have a different sequence, but that encode the same or a similar glucoamylase protein that is heterologous to the yeast. The engineered yeast exhibit desirable bioproduct production profiles during a fermentation process. A fermentation medium with a starch material can be fermented with the engineered yeast to provide high ethanol titers, low glycerol titers, or both.

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Plymouth, MN, United States of America

Jon Veldhouse