Cargill Inc.

Christopher K Miller

Aristos Aristidou

Pirkko Suominen

Vineet Rajgarhia

Laura Ruohonen

Marja Ilmen

Kari Koivuranta

Amit Vas

Stacey Olson

Jon Veldhouse

Ana Negrete-Raymond

Brian Jeffrey Rush

Merja Penttilä

Gregory Michael Poynter

Merja Elisa Penttila

Arlene M Fosmer

Keith M Brady

Jonathan Dwight Veldhouse

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 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 secretion signal that is: derived from at least AA 1-19 of SEQ ID NO: 73, (ii) an amino acid sequence of at least AA 1-19 of SEQ ID NO: 74, (iii) SEQ ID NO: 77 (An aa), (iv) SEQ ID NO: 75 (Sc IV), (v) SEQ ID NO: 76 (Gg LZ), or (vi) SEQ ID NO: 78(Hs SA).

Engineered yeast strains with signal sequence-modified glucoamylase polypeptides and enhanced ethanol 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 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.

Microorganisms expressing modified glucoamylase enzymes

A fermentation process for fermenting a starch hydrolysate containing 60-98 weight percent of glucose based on total carbohydrate and 0.3-5% weight percent of isomaltose based on total carbohydrate to a non-ethanol fermentation product is carried out. The method comprises: a) forming a fermentation broth containing the starch hydrolysate and a genetically modified microorganism containing i) an exogenous gene encoding transporter capable of transporting isomaltose ii) an exogenous gene encoding an enzyme capable of converting isomaltose to glucose; and b) fermenting the starch hydrolysate in the fermentation broth to produce a non-ethanol fermentation product. This fermentation process may be carried out as a single step fermentation or a batch process. The genetically modified microorganism may contain an exogenous gene encoding an enzyme that catalyzes the formation of a product other than ethanol.

Method for fermenting sugars using genetically engineered yeast

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.

Glucoamylase-modified yeast strains and methods for bioproduct production

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

Genetically modified yeast species, and fermentation processes using genetically modified yeast

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications', include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

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Andover, MN, United States of America

Christopher K Miller