Microorganism expressing xylose isomerase

Abstract

The present invention relates to a transformed microorganism capable of (a) a higher xylose isomerase activity than the equivalent microorganism prior to transformation; and/or (b) a higher growth rate in or on a growth medium comprising xylose than the equivalent microorganism prior to transformation; and/or (c) a faster metabolism of xylose than the equivalent microorganism prior to transformation; and/or (d) a higher production of ethanol when grown anaerobically on xylose as the carbon source than the equivalent microorganism prior to transformation.

1 . A transformed microorganism capable of
 (a) a higher xylose isomerase activity than the equivalent microorganism prior to transformation; and/or   (b) a higher growth rate in or on a growth medium comprising xylose than the equivalent microorganism prior to transformation; and/or   (c) a faster metabolism of xylose than the equivalent microorganism prior to transformation; and/or   (d) a higher production of ethanol when grown anaerobically on xylose as the carbon source than the equivalent microorganism prior to transformation;   
       wherein said microorganism has been transformed with a nucleotide sequence encoding a xylose isomerase wherein said xylose isomerase is an exogenous xylose isomerase and wherein said xylose isomerase is an exogenous xylose isomerase derived from a  Lactococcus  species; 
       and wherein said transformed microorganism is a transformed yeast wherein said transformed yeast is  Saccharomyces.    
     
     
         2 . The microorganism according to  claim 1  wherein said microorganism has been transformed with a nucleotide sequence encoding the amino acid sequence shown as SEQ ID No 14, SEQ ID No 11, SEQ ID No 18, SEQ ID No 13, SEQ ID No 19 or SEQ ID No 20, or a variant, homologue or derivative thereof encoding an amino acid sequence having at least 75% identity to the amino acid sequence shown as SEQ ID No 14, SEQ ID No 11, SEQ ID No 18, SEQ ID No 13, SEQ ID No 19 or SEQ ID No 20. 
     
     
         3 . The microorganism according to  claim 1  wherein said microorganism has been transformed with the nucleotide sequence shown as SEQ ID No 1, SEQ ID No 10, SEQ ID 17, SEQ ID No 12, SEQ ID No 27 or SEQ ID No 28, or a variant, homologue or derivative thereof having at least 75% identity to the nucleotide sequence shown as SEQ ID No 1, SEQ ID No 10, SEQ ID 17, SEQ ID No 12, SEQ ID No 27 or SEQ ID No 28. 
     
     
         4 . An inoculum comprising a microorganism according to  claim 1 . 
     
     
         5 . A culture medium comprising a microorganism according to  claim 1 . 
     
     
         6 . The culture medium according to  claim 5  wherein said culture medium comprises a source of xylose. 
     
     
         7 . The culture medium according to  claim 5  wherein said culture medium comprises material derived from lignocellulosic material. 
     
     
         8 . A method for preparing a transformed microorganism, said method comprising the step of transforming a microorganism such that said transformed microorganism is capable of:
 (a) a higher xylose isomerase activity than the microorganism prior to transformation; and/or   (b) a higher growth rate in or on a growth medium comprising xylose than the microorganism prior to transformation; and/or   (c) a faster metabolism of xylose than the microorganism prior to transformation; and/or   (d) a higher production of ethanol when grown anaerobically on xylose as the carbon source than the microorganism prior to transformation;   
       wherein said microorganism is transformed with a nucleotide sequence encoding a xylose isomerase wherein said xylose isomerase is an exogenous xylose isomerase and wherein said xylose isomerase is an exogenous xylose isomerase derived from a  Lactococcus  species; 
       and wherein said transformed microorganism is a transformed yeast wherein said transformed yeast is  Saccharomyces.    
     
     
         9 . The method according to  claim 8  wherein said nucleotide sequence encoding a xylose isomerase comprises the nucleotide sequence shown as SEQ ID No 1, SEQ ID No 10, SEQ ID No 17, SEQ ID No 12, SEQ ID No 27 or SEQ ID No 28, or a variant, homologue or derivative thereof having at least 75% identity to the nucleotide sequence shown as SEQ ID No 1, SEQ ID No 10, SEQ ID No 17, SEQ ID No 12, SEQ ID No 27 or SEQ ID No 28. 
     
     
         10 . The method according to  claim 8  wherein said nucleotide sequence encoding a xylose isomerase is in an expression vector encoding same. 
     
     
         11 . A fermentation method comprising culturing in a culture medium a microorganism according to  claim 1 . 
     
     
         12 . A method for producing a product derived from xylose comprising culturing in a culture medium a microorganism according to  claim 1 . 
     
     
         13 . A method for producing a biofuel wherein said method comprises the step of culturing in a culture medium a microorganism according to  claim 1 . 
     
     
         14 . The method according to  claim 13  wherein said method further comprises the step of obtaining the biofuel from the culture medium. 
     
     
         15 . A biofuel obtained by the method according to  claim 13 . 
     
     
         16 . (canceled) 
     
     
         17 . The method according to  claim 12  wherein said product derived from xylose is selected from the group consisting of xylulose, xylulose-5-phosphate, ethanol, aromatic amino acids, lactic acid, succinic acid, acetic acid, acetaldehyde, furfural, itaconic acid, glutamic acid, citric acid, cresol, lysine, 3-hydroxypropionic acid, poly-3-hydroxyalkanoates, protocatechuic acid, pyrocatechol, guaiacol, veratrol, resveratrol, vanillin, vanillic acid, vanillyl alcohol, muconic acid, adipic acid, 4-hydroxybenzoic acid, 4-hydroxybenzaldehyde, 4-methoxybenzoic acid, 4-aminobenzoate, 4-hydroxyaniline, 4-methoxyaniline, quinol, anisole, phenol, anthranilic acid, 3-hydroxyanthranilate, 2,3-dihydroxybenzoic acid, 2-aminophenol, 1,4-cyclohexanedione, isoprene and styrene. 
     
     
         18 . (canceled) 
     
     
         19 . A fermentation method comprising culturing in a culture medium a microorganism according to a microorganism prepared by the method  claim 8 . 
     
     
         20 . A method for producing a product derived from xylose comprising culturing in a culture medium a microorganism according to a microorganism prepared by the method of  claim 8 . 
     
     
         21 . A method for producing a biofuel wherein said method comprises the step of culturing in a culture medium a microorganism according to a microorganism prepared by the method  claim 8 .