The invention relates to a recombinant yeast comprising a recombinant yeast comprising a nucleotide sequence coding for a glycerol dehydrogenase, a nucleotide sequence coding for a ribulose-1,5-biphosphate carboxylase oxygenase (EC 4.1.1.39); a nucleotide sequence coding for a phosphoribulokinasey (EC 2.7.1.19); a nucleotide sequence allowing the expression of a glucoamylase (EC 3.2.1.20 or 3.2.1.3); and optionally a nucleotide sequence coding for a glycerol transporter. This cell can be used for the production of ethanol and advantageously produces little or no glycerol.

The invention is directed to an engineered yeast including an exogenous nucleic acid encoding a glucoamylase comprising SEQ ID NO:1 and SEQ ID NO:4, or a variant thereof. The engineered yeast are able to provide glucoamylase into a fermentation media and cause degradation of starch material generating glucose for fermentation to a desired bioproduct, such as ethanol. High titers of bioproduct (e.g., 70 g/kg of ethanol) can be achieved, along with low residual glucose levels. Further the yeast exhibit good growth and bioproduct product at temperatures of 32° C. or greater.

The present invention relates to alpha-amylase variants comprising substitutions at positions corresponding to positions 268 and 293 of SEQ ID NO: 1, in particular substitutions selected from the group consisting of: 268G+293Y; 268G+293F; 268G+293W; 268G+293H; 268G+293A; 268G+293Q; 268A+293Y; 268A+293F; 268A+293W; 268A+293H; 268A+293A; 268A+293Q; 268P+293Y; 268P+293F; 268P+293W; 268P+293H; 268P+293A; 268P+293Q; 268S+293Y; 268S+293F; 268S+293W; 268S+293H; 268S+293A; 268S+293Q; 268T+293Y; 268T+293F; 268T+293W; 268T+293H; 268T+293A; 268T+293Q; 268V+293Y; 268V+293F; 268V+293W; 268V+293H; 268V+293A; 268V+293Q; 268I+293Y; 268I+293F; 268I+293W; 268I+293H; 268I+293A; 268I+293Q; 268L+293Y; 268L+293F; 268L+293W; 268L+293H; 268L+293A; 268L+293Q; 268M+293Y; 268M+293F; 268M+293W; 268M+293H; 268M+293A; 268M+293Q; and wherein the variant has at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100% sequence identity to a parent alpha amylase selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, and SEQ ID NO: 18. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The present invention provides for a mechanism to reduce glycerol production and increase nitrogen utilization and ethanol production of recombinant microorganisms. One aspect of this invention relates to strains of S. cerevisiae with reduced glycerol productivity that get a kinetic benefit from higher nitrogen concentration without sacrificing ethanol yield. A second aspect of the invention relates to metabolic modifications resulting in altered transport and/or intracellular metabolism of nitrogen sources present in corn mash.

The present invention relates to isolated polypeptides having glucoamylase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

The invention relates to a recombinant yeast comprising a nucleotide sequence allowing the expression of a glucoamylasey (EC 3.2.1.20 or 3.2.1.3). This cell can be used for the production of ethanol and advantageously produces little or no glycerol.

The present invention relates to glucoamylase variants having an increase in raw starch activity compared to the guy-coamylase disclosed as SEQ ID NO: 2, comprising one or more modifications in the catalytic domain and/or one or more modifications in the starch binding domain selected from: a) at least one, preferably at least two, preferably at least three, preferably at least four of: V18M, T43K, N112L, T116R, A117Q, G120S, A271F, Y295W, Q318Y; and/or b) Introducing at least three, preferably at least four substitutions selected from the group: S458C, S458SCGG, S458SGGC, A493V, A518K, E520Q, N527M, S540K, R, S(G)546P, T(V)549W, N503R, N539R+I541Y+T543V+A545S+S546GCGV+G547S+S548T+T549A. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

The invention is directed to an engineered yeast including an exogenous nucleic acid encoding a glucoamylase comprising SEQ ID NO:1 and SEQ ID NO:4, or a variant thereof. The engineered yeast are able to provide glucoamylase into a fermentation media and cause degradation of starch material generating glucose for fermentation to a desired bioproduct, such as ethanol. High titers of bioproduct (e.g., 70 g/kg of ethanol) can be achieved, along with low residual glucose levels. Further the yeast exhibit good growth and bioproduct product at temperatures of 32° C. or greater.

Methods, compositions, and kits are provided for rapidly analyzing microbial growth and/or number in a plurality of water-in-oil emulsion droplets.

The invention relates to enzyme compositions comprising a glucoamylase, an alpha-amylase, and optionally a cellulolytic composition and/or a protease. The invention also relates to the use thereof in processes of producing sugars and/or fermentation products from starch-containing material by saccharifying and/or fermenting starch-containing material at a temperature below the initial gelatinization temperature.