Recombinant bacteria comprising novel sucrose transporters

Abstract

Recombinant bacteria capable of metabolizing sucrose are described. The recombinant bacteria comprise in their genome or on at least one recombinant construct, a novel nucleotide sequence encoding a polypeptide having sucrose transporter activity and a nucleotide sequence encoding a polypeptide having sucrose hydrolase activity. These nucleotide sequences are each operably linked to the same or a different promoter. Recombinant bacteria capable of metabolizing sucrose to produce glycerol and/or glycerol-derived products such as 1,3-propanediol and 3-hydroxypropionic acid are also described.

What is claimed is: 
     
         1 . A recombinant bacterium comprising in its genome or on at least one recombinant construct:
 (a) a nucleotide sequence encoding a polypeptide having sucrose transporter activity, said polypeptide having at least 95% sequence identity, based on a Clustal W method of alignment, when compared to an amino acid sequence selected from the group consisting of SEQ ID NO:68, SEQ ID NO:70, SEQ ID NO:72, SEQ ID NO:74, SEQ ID NO:76, SEQ ID NO:78, SEQ ID NO:80, SEQ ID NO:82, SEQ ID NO:84, SEQ ID NO:86, SEQ ID NO:88, SEQ ID NO:90, SEQ ID NO:92, and SEQ ID NO:94; and   (b) a nucleotide sequence encoding a polypeptide having sucrose hydrolase activity;   
       wherein (a) and (b) are each operably linked to the same or a different promoter, further wherein said recombinant bacterium is capable of metabolizing sucrose. 
     
     
         2 . The bacterium of  claim 1 , wherein the polypeptide having sucrose hydrolase activity is classified as EC 3.2.1.26 or EC 2.4.1.7. 
     
     
         3 . The recombinant bacterium of  claim 1  further comprising in its genome or on at least one recombinant construct, a nucleotide sequence encoding a polypeptide having fructokinase activity. 
     
     
         4 . The bacterium of  claim 3 , wherein the polypeptide having fructokinase activity is classified as EC 2.7.1.4, EC 2.7.1.3, or EC 2.7.1.1. 
     
     
         5 . The recombinant bacterium of  claim 1  wherein said bacterium is selected from the group consisting of the genera:  Escherichia, Klebsiella, Citrobacter , and  Aerobacter.    
     
     
         6 . The recombinant bacterium of  claim 5  wherein said bacterium is  Escherichia coli.    
     
     
         7 . The recombinant bacterium of  claim 1  wherein the recombinant bacterium produces 1,3-propanediol, glycerol, and/or 3-hydroxypropionic acid. 
     
     
         8 . A process for making glycerol, 1,3-propanediol and/or 3-hydroxypropionic acid from sucrose comprising:
 a) culturing the recombinant bacterium of  claim 7  in the presence of sucrose; and   b) optionally, recovering the glycerol, 1,3-propanediol and/or 3-hydroxypropionic acid produced.