The invention relates to a recombinant cell, preferably a yeast cell comprising: a) one or more heterologous genes encoding a glycerol dehydrogenase activity; b) one or more genes encoding a dihydroxyacetone kinase (E.C. 2.7.1.28 and/or E.C. 2.7.1.29); c) one or more heterologous genes encoding a ribulose-1,5-biphosphate carboxylase oxygenase (EC 4.1.1.39, RuBisCO); and d) one or more heterologous genes encoding a phosphoribulokinase (EC 2.7.1.19, PRK); and optionally e) one or more heterologous genes encoding for a glycerol transporter. This cell can be used for the production of ethanol and advantageously produces little or no glycerol.

An engineered bacterial strain expressing dehydrogenases capable of oxidizing D- sorbitol to 2-keto-gulonic acid is provided by the present invention. Methods of using same in a one-pot synthesis of L-ascorbic acid (vitamin C) are also described.

The invention discloses an alcohol dehydrogenase mutant and use thereof. The alcohol dehydrogenase mutant of the present invention has high thermal stability and enables high catalytic efficiency and high conversion rate (i.e. space time yield) in the asymmetric reduction of prochiral diaryl ketones to produce chiral diaryl alcohols. Therefore, the alcohol dehydrogenase mutant of the present invention has extremely high prospect of application in the production of chiral diaryl alcohols, such as (S)-(4-chlorophenyl)-(pyridin-2-yl)-methanol, (R)-(4-chlorophenyl)-(pyridin-2-yl)-methanol.

Recombinant microorganisms, plants, and plant cells are disclosed that have been engineered to have reduced levels or activity of one or more alcohol dehydrogenases or aldehyde reductases thereby increasing the production of benzylisoquinoline alkaloids and/or benzylisoquinoline alkaloid precursors.

Cell that is genetically modified comprising: a) one or more nucleotide sequence encoding a NAD.sub.+-dependent acetylating acetaldehyde dehydrogenase (E.C. 1.2.1.10); b) one or more nucleotide sequence encoding a acetyl-CoA synthetase (E.C. 6.2.1.1); c) one or more nucleotide sequence encoding a glycerol dehydrogenase (E.C. 1.1.1.6); and d) one or more nucleotide sequence encoding a dihydroxyacetone kinase (E.C. 2.7.1.28 or E.C. 2.7.1.29).

The invention relates to a recombinant cell, preferably a yeast cell comprising: a) one or more heterologous genes encoding a glycerol dehydrogenase activity; b) one or more genes encoding a dihydroxyacetone kinase (E.C. 2.7.1.28 and/or E.C. 2.7.1.29); c) one or more heterologous genes encoding a ribulose-1,5-biphosphate carboxylase oxygenase (EC 4.1.1.39, RuBisCO); and d) one or more heterologous genes encoding a phosphoribulokinase (EC 2.7.1.19, PRK); and optionally e) one or more heterologous genes encoding for a glycerol transporter. This cell can be used for the production of ethanol and advantageously produces little or no glycerol.

The invention describes a process for the production of ethanol from a composition comprising glucose and between 50 μM and 100 mM acetic acid, said process comprising fermenting said composition in the presence of a recombinant yeast which is capable to convert acetic acid anaerobically; maintaining the amount of undissociated acetic acid at a value of at least 50 μM; and recovering the ethanol. Said process is useful for both starch and cellulosic based, acetic acid containing hydrolysates and advantageously results in a greater consumption of acetic acid and thus higher ethanol yields.

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 invention relates to a recombinant cell, preferably a yeast cell comprising: a) one or more heterologous genes encoding a glycerol dehydrogenase activity; b) one or more genes encoding a dihydroxyacetone kinase (E.C. 2.7.1.28 and/or E.C. 2.7.1.29); c) one or more heterologous genes encoding a ribulose-1,5-biphosphate carboxylase oxygenase (EC 4.1.1.39, RuBisCO); and d) one or more heterologous genes encoding a phosphoribulokinase (EC 2.7.1.19, PRK); and optionally e) one or more heterologous genes encoding for a glycerol transporter, wherein the recombinant yeast comprises overexpression of one or more PPP-genes. This cell can be used for the production of ethanol and advantageously produces little or no glycerol.

Recombinant strains are obtained for the production of allulose, allose, and allitol by regulating intracellular glucose metabolism, reducing the enzyme activity of fructose 6-phosphate kinase, and enhancing the enzyme activities of glucokinase and glucose-6-phosphate isomerase, allulose 6-phosphate 3-epimerase, allulose 6-phosphate phosphatase, fructose permease and fructokinase, and optionally enhancing the enzyme activities of ribose 5-phosphate isomerase, allose 6-phosphate phosphatase, ribitol dehydrogenase, glycerol permease, glycerol dehydrogenase, and dihydroxyacetone kinase. A method for producing allulose and allose is an extracellular multienzyme cascade method. Multienzyme cascade catalysis and fermentation are coupled to improve the conversion rate of starch sugar or sucrose to the synthesized allulose.