This application describes non-naturally occurring host cells for enhanced 1,3-butanediol (1,3-BDO) production, methods for producing 1,3-BDO using such non-naturally occurring host cells, and 1,3-BDO products produced by such non-naturally occurring host cells and methods.

Methods of microbial screening for identifying alcohol acyltransferases for ester biosynthesis and submodules for ester pathways to produce butyryl-coenzyme A derived esters are disclosed. The method includes the introduction preselected plasmids into a respective host strain to form engineered microbes, in situ fermentation thereof followed by a colorimetric assay for quantification of production of the target ester. In situ fermentation includes inoculating each well of a microplate that have a culture media for producing target esters with one of the engineered microbes, adding an overlay of a solvent to each, and incubating the same. The colorimetric assay includes transfer of a quantity of the overlay from each well to respective clean wells of a new microplate, treatment of each well to form an iron-hydroxamic acid complex aqueous phase, centrifugation of the microplate, and measurement of the absorbance at 520 nm and comparison to a standard curve for the target ester.

Described are compositions and methods relating to yeast having a genetic mutation that results in decreased amounts of Cdc42 effector proteins, resulting in increased alcohol and lysine production. Such yeast is well-suited for use commercial alcohol production to increase yields and to increase the value of Such yeast is well-suited for use commercial alcohol production to increase yields and to increase the value of amino-acid-containing, fermentation-co-products.

A recombinant yeast cell comprising a nucleotide sequence encoding a protein, which protein comprises an amino acid sequence of SEQ ID NO: 01 or an amino acid sequence which has at least 90% sequence identity, preferably at least 95%, 98%, or 99% sequence identity with the amino acid sequence of SEQ ID NO: 01.

Described are compositions and methods relating to yeast having a genetic mutation that results in decreased amounts of Cdc42 effector proteins, resulting in increased alcohol and lysine production. Such yeast is well-suited for use commercial alcohol production to increase yields and to increase the value of Such yeast is well-suited for use commercial alcohol production to increase yields and to increase the value of amino-acid-containing, fermentation-co-products.

A recombinant yeast cell functionally expressing: a nucleic acid sequence encoding a native protein having transketolase activity (EC 2.2.1.1); and a nucleic acid sequence encoding a heterologous protein having transketolase activity (EC 2.2.1.1).

The present invention relates to a yeast cell, in particular a recombinant yeast cell, the cell lacking enzymatic activity needed for the NADH-dependent glycerol synthesis or the cell having a reduced enzymatic activity with respect to the NADH-dependent glycerol synthesis compared to its corresponding wild-type yeast cell, the cell comprising one or more heterologous nucleic acid sequences encoding an NAD.sup.+-dependent acetylating acetaldehyde dehydrogenase (EC 1.2.1.10) activity. The invention further relates to the use of a cell according to the invention in the preparation of ethanol.

The present invention concerns a metabolically engineered microorganism for glycine bioproduction or a salt or an ester thereof, the genome of said microorganism comprises an attenuation of the expression of genes encoding enzymes having glycine cleavage system activity as defined by E.C. 1.4.1.27 together with an overexpressing of threonine dehydrogenase dependent pathway as defined by EC E.C. 1.1.1.103 and E.C. 2.3.1.29 and/or with a threonine aldolase dependent pathway as defined by E.C. 4.1.2.48 or EC 4.1.2.42 or any of its catalytically active variants, its use for the production of glycine or one of its salts or esters. The present invention also concerns a fermentation process using said metabolically engineered microorganism for the production of glycine or one of its salts or esters.

Provided are a method for constructing a lactic acid-producing strain, a lactic acid-producing strain and use thereof. The method for constructing lactic acid-producing strains is characterized by genetically engineering a starting strain to increase lactic acid production, wherein the engineering includes: 1) introducing a lactic acid synthesis pathway; 2) optimizing the lactic acid synthesis pathway; and 3) inhibiting by-product synthesis pathways.

The present invention relates to a yeast cell, in particular a recombinant yeast cell, the cell lacking enzymatic activity needed for the NADH-dependent glycerol synthesis or the cell having a reduced enzymatic activity with respect to the NADH-dependent glycerol synthesis compared to its corresponding wild-type yeast cell, the cell comprising one or more heterologous nucleic acid sequences encoding an NAD+-dependent acetylating acetaldehyde dehydrogenase (EC 1.2.1.10) activity. The invention further relates to the use of a cell according to the invention in the preparation of ethanol.