The present invention relates to the field of yeast fermentations. More particularly, the invention relates to mutant alleles useful to engineer industrially relevant traits in yeast.

One aspect provides an ultrapure, hypoallergenic sacrosidase. Another aspect provides a solution of sacrosidase in about 1:1 glycerol/water having an enzymatic activity of at least about 7500 IU/mL and a residual papain concentration that does not include an allergic reaction in a human patient when given a dose of about 2.0 mL/day.

The invention relates to yeast cells with useful characteristics, including being capable of utilizing panose as sole carbon source and/or capable of utilizing one or more dipeptidesas sole nitrogen source. The invention also relates to yeast cells with useful genotypes including comprising at least 4 allelic genes encoding IMA1p and/or at least two allelic genes encoding IMA5p.

A process for the production of ethanol. comprising: fermentation of a feed. under anaerobic conditions. wherein the feed contains a di-saccharide. oligo-saccharide and/or poly-saccharide and wherein the fermentation is carried out in the presence of a recombinant yeast cell. which recombinant yeast produces a combination of proteins having glucosidase activity: and recovery of ethanol. and a recombinant yeast cell for use therein.

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.

One aspect provides an ultrapure, hypoallergenic sacrosidase. Another aspect provides a solution of sacrosidase in about 1:1 glycerol/water having an enzymatic activity of at least about 7500 IU/mL and a residual papain concentration that does not include an allergic reaction in a human patient when given a dose of about 2.0 mL/day.

A method for producing glucose and derivatives thereof by means of biotransformation with a recombinant yeast, which belongs to the technical field of synthetic biology. A construction method comprises any one of the following steps: i, knocking out metabolic pathway-related enzymes of glucose and derivatives thereof in a yeast strain; ii, enhancing or using an activity of synthetic pathway-related enzymes of glucose and derivatives thereof in the yeast strain; and iii, enhancing or using a capability of glucose and derivatives thereof in the yeast strain to enter and exit the yeast. Further provided are a recombinant yeast strain capable of producing glucose or derivatives thereof at a high yield and the use thereof in the conversion of a non-grain low-carbon carbon source. The low-carbon non-grain carbon source synthesized by means of using photoelectrocatalysis or traditional chemical industry is used as a substrate, and rapid preparation of food product raw materials glucose and derivatives thereof from the non-grain carbon source is realized by means of recombinant yeast cells.

One aspect provides an ultrapure, hypoallergenic sacrosidase. Another aspect provides a solution of sacrosidase in about 1:1 glycerol/water having an enzymatic activity of at least about 7500 IU/mL and a residual papain concentration that does not include an allergic reaction in a human patient when given a dose of about 2.0 mL/day.

Disclosed are recombinant mutant isomaltase enzymes, and pharmaceutical compositions comprising an isomaltase enzyme, e.g., a recombinant mutant isomaltase enzyme, and an optional invertase enzyme. The enzymes and compositions can be used, among other things, to treat congenital sucrase-isomaltase deficiency (CSID).

Disclosed are recombinant mutant invertase enzymes. Also disclosed are pharmaceutical compositions comprising an invertase enzyme, e.g., a recombinant mutant invertase enzyme, and an optional isomaltase enzyme. The enzymes and compositions can be used, among other things, to treat congenital sucrase-isomaltase deficiency (CSID).