Functional sugar polymers from inexpensive sugar sources and apparatus for preparing same

Abstract

A process for preparing functional sugar polymers comprising transferring a monosaccharide or oligosaccharide to an acceptor, removing by-products, separating polymers which have not achieved the desired chain length and recycling these underdeveloped polymers, and an apparatus for producing same.

What is claimed is:  
     
         1 . A process to produce straight or branched carbohydrate polymers comprising: 
 a) transferring by selective catalytic transfer a monosaccharide or oligosaccharide residue from a carbohydrate donor to an acceptor;    b) removing any by-products from the reaction mixture formed in step a) which may inhibit yield or selectivity;    c) separating polymers which have not achieved the is desired chain length; and    d) recycling the polymers which have not achieved the desired chain length.    
     
     
         2 . The process of  claim 1  where the selective catalyst is an enzyme.  
     
     
         3 . The process of  claim 2 , wherein the carbohydrate donor is a sugar nucleotide, a glycosyl phosphate, a disaccharide or an oligosaccharide.  
     
     
         4 . The process of  claim 3  wherein the monosaccharide or oligosaccharide is selected from glucose, galactose, fructose, fucose, sialic acid, N-acetyl glucosamine, N-acetyl galactosamine, glucuronic acid, iduronic acid, xylose, and mannose.  
     
     
         5 . The process of  claim 1  in which the enzyme used is produced in-situ by an appropriate organism.  
     
     
         6 . The process of  claim 1 , wherein the carbohydrate polymer produced is inulin.  
     
     
         7 . An apparatus for producing straight or branched carbohydrate polymers of a desired chain length comprising: 
 a) a reactor in which a monosaccharide or oligosaccharide residue is transferred by selective catalytic transfer from a carbohydrate donor to an acceptor;    b) means for removing by-products from the reaction of step a);    c) means for separating polymers which have not achieved the desired chain length; and    d) means for recycling the polymer chains which have not achieved the desired chain length back to the reactor.    
     
     
         8 . The apparatus of  claim 7  where the means for separating polymers is at least one membrane.  
     
     
         9 . The apparatus of  claim 8  in which the reactor and the membrane housing are a single unit.  
     
     
         10 . The apparatus of  claim 7  where the means for separating polymers utilizes chromatography.  
     
     
         11 . The apparatus of  claim 7  where the means for separating polymers utilizes chromatography selected from ligand exchange, size exclusion, and an ion-exchange resin.  
     
     
         12 . The apparatus of  claim 11  in which the selective catalyst is an enzyme.  
     
     
         13 . The apparatus of  claim 12 , in which the enzyme is suspended in, or attached, to the resin.  
     
     
         14 . The apparatus of  claim 7  where the means for separating polymers utilizes selective crystallization.  
     
     
         15 . The apparatus of  claim 7  where the means for separating polymers utilizes selective precipitation.  
     
     
         16 . The process in  claim 1  where the process is continuous, batch, or semi-batch.