The present invention relates to eukaryotic cells which have the ability to isomerise xylose directly into xylulose. The cells have acquired this ability by transformation with nucleotide sequences coding for a xylose isomerase that has one or more specific sequence elements typical for isomerases having the ability of functional expression in yeasts, such as e.g. xylose isomerases obtainable from a bacterium of the genera Clostridium and Fusobacterium or a tunicate form the genus Ciona. The cell preferably is a yeast or a filamentous fungus, more preferably a yeast is capable of anaerobic alcoholic fermentation.

The invention relates to a process for the preparation of a fermentation product from ligno-cellulosic material, comprising the following steps: a) optionally pre-treatment of the ligno-cellulosic material; b) optionally washing of the optionally pre-treated ligno-cellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pre-treated ligno-cellulosic material using an enzyme composition comprising at least two cellulase and whereby the enzyme composition at least comprises GH61; d) whereby less than 7.5 mg enzyme composition/g glucan (on dry matter and enzyme as protein) or less than 3.0 mg enzyme composition/g feedstock (on dry matter and enzyme as protein) is used; and e) fermentation of the hydrolyzed ligno-cellulosic material to produce a fermentation product; and f) optionally recovery of a fermentation product;
wherein before and/or during the enzymatic hydrolysis oxygen is added to the ligno-cellulosic material.

The invention relates to a process for the preparation of a fermentation product from ligno-cellulosic material, comprising the following steps: a) optionally pre-treatment of the ligno-cellulosic material; b) optionally washing of the optionally pre-treated ligno-cellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pre-treated ligno-cellulosic material using an enzyme composition comprising at least two cellulase and whereby the enzyme composition at least comprises GH61; d) whereby less than 7.5 mg enzyme composition/g glucan (on dry matter and enzyme as protein) or less than 3.0 mg enzyme composition/g feedstock (on dry matter and enzyme as protein) is used; and e) fermentation of the hydrolyzed ligno-cellulosic material to produce a fermentation product; and f) optionally recovery of a fermentation product;
wherein before and/or during the enzymatic hydrolysis oxygen is added to the ligno-cellulosic material.

A process of producing an organic compound and/or an intermediary compound by feeding carbon dioxide to a culture of Cyanobacteria cells and subjecting the culture to light, wherein the cells are capable of expressing a nucleic acid molecule that confers the ability to convert a glycolytic intermediate into said organic/intermediary compound. The expression of the nucleic acid molecule is under the control of a regulatory system which responds to a change in the concentration of a nutrient in the culture.

A process of producing an organic compound and/or an intermediary compound by feeding carbon dioxide to a culture of Cyanobacteria cells and subjecting the culture to light, wherein the cells are capable of expressing a nucleic acid molecule that confers the ability to convert a glycolytic intermediate into said organic/intermediary compound. The expression of the nucleic acid molecule is under the control of a regulatory system which responds to a change in the concentration of a nutrient in the culture.

Provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway that can enhance the availability of reducing equivalents in the presence of methanol. Such reducing equivalents can be used to increase the product yield of organic compounds produced by the microbial organism, such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Also provided herein are methods for using such an organism to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.

Provided herein is a non-naturally occurring microbial organism having a methanol metabolic pathway that can enhance the availability of reducing equivalents in the presence of methanol. Such reducing equivalents can be used to increase the product yield of organic compounds produced by the microbial organism, such as 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol. Also provided herein are methods for using such an organism to produce 1,2-propanediol, n-propanol, 1,3-propanediol or glycerol.

The present disclosure relates to recombinant yeast host cells having (i) a first genetic modification for reducing the production of one or more native enzymes that function to produce glycerol or regulating glycerol synthesis and/or allowing the production of an heterologous glucoamylase and (ii) a second genetic modification for reducing the production of one or more native enzymes that function to produce trehalose or regulating trehalose synthesis and/or allowing the expression of an heterologous trehalase. The recombinant yeast host cells can be used to limit the production of (yeast-produced) trehalose (particularly extracellular trehalose) during fermentation and, in some embodiments, can increase the production of a fermentation product (such as, for example, ethanol).

The present disclosure relates to recombinant yeast host cells having (i) a first genetic modification for reducing the production of one or more native enzymes that function to produce glycerol or regulating glycerol synthesis and/or allowing the production of an heterologous glucoamylase and (ii) a second genetic modification for reducing the production of one or more native enzymes that function to produce trehalose or regulating trehalose synthesis and/or allowing the expression of an heterologous trehalase. The recombinant yeast host cells can be used to limit the production of (yeast-produced) trehalose (particularly extracellular trehalose) during fermentation and, in some embodiments, can increase the production of a fermentation product (such as, for example, ethanol).

The invention relates to a cell which comprises a nucleotide sequence encoding a xylose isomerase, wherein the amino acid sequence of the xylose isomerase has at least 75% sequence identity to the amino acid sequence set out in SEQ ID NO: 2 and wherein the nucleotide sequence is heterologous to the host. A cell of the invention may be used in a process for producing a fermentation product, such as ethanol. Such a process may comprise fermenting a medium containing a source of xylose with a cell of the invention such that the cell ferments xylose to the fermentation product.