Methods and compositions for improving sugar transport, mixed sugar fermentation, and production of biofuels

Abstract

The present disclosure relates to host cells containing a recombinant polynucleotide encoding a polypeptide where the polypeptide transports cellodextrin into the cell. The present disclosure further relates to methods of increasing transport of cellodextrin into a cell, methods of increasing growth of a cell on a medium containing cellodextrin, methods of co-fermenting cellulose-derived and hemicellulose-derived sugars, and methods of making hydrocarbons or hydrocarbon derivatives by providing a host cell containing a recombinant polynucleotide encoding a polypeptide where the polypeptide transports cellodextrin into the cell. The present disclosure relates to host cells containing a recombinant polynucleotide encoding a polypeptide where the polypeptide transports a pentose into the cell, methods of increasing transport of a pentose into a cell, methods of increasing growth of a cell on a medium containing pentose sugars, and methods of making hydrocarbons or hydrocarbon derivatives by providing a host cell containing a recombinant polynucleotide encoding a polypeptide where the polypeptide transports a pentose into the cell.

1 .- 17 . (canceled) 
     
     
         18 . A method of co-fermenting cellulose-derived and hemicellulose-derived sugars, comprising:
 providing a host cell, wherein the host cell comprises a first recombinant polynucleotide encoding a cellodextrin transporter and a second recombinant polynucleotide encoding a catalytic domain of a β-glucosidase, and   culturing the host cell in a medium comprising a cellulose-derived sugar and a hemicellulose-derived sugar, wherein expression of the recombinant polynucleotides enables co-fermentation of the cellulose-derived sugar and the hemicellulose-derived sugar.   
     
     
         19 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 1 comprises SEQ ID NO: 1. 
     
     
         20 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 2 comprises SEQ ID NO: 2. 
     
     
         21 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and a loop connecting transmembrane α-helix 2 and transmembrane α-helix 3 comprises SEQ ID NO: 3. 
     
     
         22 . The method of  claim 18  wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 5 comprises SEQ ID NO: 4. 
     
     
         23 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 6 comprises SEQ ID NO: 5. 
     
     
         24 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and the sequence between transmembrane α-helix 6 and transmembrane α-helix 7 comprises SEQ ID NO: 6. 
     
     
         25 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 7 comprises SEQ ID NO: 7. 
     
     
         26 . The method of  claim 18 , wherein the first recombinant polynucleotide encodes a polypeptide comprising transmembrane α-helix 1, transmembrane α-helix 2, transmembrane α-helix 3, transmembrane α-helix 4, transmembrane α-helix 5, transmembrane α-helix 6, transmembrane α-helix 7, transmembrane α-helix 8, transmembrane α-helix 9, transmembrane α-helix 10, transmembrane α-helix 11, and transmembrane α-helix 12, and transmembrane α-helix 10 and transmembrane α-helix 11 and the sequence between them comprise SEQ ID NO: 8. 
     
     
         27 . The method of  claim 18 , wherein the cellodextrin transporter has at least 29%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or at least 100% amino acid identity to NCU00801 or NCU08114. 
     
     
         28 . The method of  claim 18 , wherein the β-glucosidase is from  Neurospora crassa.    
     
     
         29 . The method of  claim 18 , wherein the β-glucosidase is NCU00130. 
     
     
         30 . The method of  claim 18 , wherein the host cell further comprises one or more recombinant polynucleotides encoding one or more enzymes involved in pentose utilization. 
     
     
         31 . The method of  claim 30 , wherein the one or more enzymes involved in pentose utilization are selected from the group consisting of L-arabinose isomerase, L-ribulokinase, L-ribulose-5-P 4 epimerase, xylose isomerase, xylulokinase, aldose reductase, L-arabinitol 4-dehydrogenase, L-xylulose reductase, and xylitol dehydrogenase. 
     
     
         32 . The method of  claim 18 , wherein the host cell further comprises a third recombinant polynucleotide encoding a pentose transporter. 
     
     
         33 . The method of  claim 32 , wherein the pentose transporter is selected from the group consisting of NCU00821, NCU04963, NCU06138, STL12/XUT6, SUT2, SUT3, XUT1, and XUT3. 
     
     
         34 . The method of  claim 18 , wherein the cellulose-derived sugar is selected from the group consisting of cellobiose, cellotriose, and cellotetraose, and the hemicellulose-derived sugar is xylose.