Dsm IP Assets B.v.

Technische Universiteit Delft

Aaron Adriaan Winkler

Jacobus Thomas Pronk

Johannes Pieter Van Dijken

Sipko Maarten Kuyper

Antonius Jeroen Adriaan Van Maris

Liang Wu

Wilhelmus Theodorus Antonius Maria De Laat

Hendrik Wouter Wisselink

Johannes Hendrik Winde

Wilhelmus Theordorus Antonius Maria De Laat

Ulrike Maria Mueller

Johannes Hendrik De Winde

Lourina Madeleine Raamsdonk

The present invention relates to a method of identifying a heterologous polypeptide having enzymatic activity for converting pyruvate, acetaldehyde or acetate into acetyl-CoA in (the cytosol of) a yeast cell comprising: a) providing a mutated yeast cell comprising a deletion of at least one gene of the (PDH) by-pass, selected from the genes encoding the enzymes pyruvate decarboxylase (PDC), acetaldehyde dehydrogenase (ALD), and acetyl-CoA synthetase (ACS); b) transforming said mutated yeast cell with an expression vector comprising a heterologous nucleotide sequence encoding a candidate polypeptide having potential enzymatic activity for converting pyruvate, acetaldehyde or acetate into acetyl-CoA; c) testing said recombinant mutated yeast cell for its ability to grow on minimal medium containing glucose as sole carbon source, and d) identifying said candidate polypeptide as a heterologous polypeptide having enzymatic activity for converting pyruvate, acetaldehyde or acetate into acetyl-CoA in (the cytosol of) said yeast cell when growth of said cell is observed. The invention further relates to a method of producing a fermentation production such as butanol.

Acetyl-CoA producing enzymes in yeast

The invention relates to an eukaryotic cell expressing nucleotide sequences encoding the ara A, ara B and ara D enzymes whereby the expression of these nucleotide sequences confers on the cell the ability to use L-arabinose and/or convert L-arabinose into L-ribulose, and/or xylulose 5-phosphate and/or into a desired fermentation product such as ethanol. Optionally, the eukaryotic cell is also able to convert xylose into ethanol.

Metabolic engineering of arabinose-fermenting yeast cells

The present invention relates to genetic modifications in eukaryotic host cells that have been transformed to express a xylose isomerase that confers on the host cell the ability to isomerize xylose to xylulose. These genetic modifications are aimed at improving the efficiency of xylose metabolism and include. e.g., reduction of nonspecific aldose reductase activity, increased xylulose kinase activity and increased flux of the pentose phosphate pathway. The modified host cells of the invention are suitable for the production of a wide variety of fermentation products, including ethanol, in fermentation processes in which a source of xylose or a source of xylose and glucose are used as carbon source.

Metabolic engineering of xylose-fermenting eukaryotic cells

The present invention relates to further genetic modifications in eukaryotic host cells that have been transformed to express a xylose isomerase that confers the host cell the ability of isomerizing xylose to xylulose. The further genetic modifications are aimed at improving the efficiency of xylose metabolism and include e.g. reduction of unspecific aldose reductase activity, increased xylulose kinase activity and increased flux of the pentose phosphate pathway. The modified host cells of the invention are suitable for the production of a wide variety of fermentation products, including ethanol, in fermentation processes in which a source of xylose or a source of xylose and glucose are used as carbon source.

Xylose-fermenting yeast engineered to increase flux of the pentose phosphate pathway

Growing community of inventors

The Hague, Netherlands

Aaron Adriaan Winkler