Method of Producing L-Amino Acid

Abstract

An L-amino acid is produced by culturing a microorganism belonging to the family Enterobacteriaceae having an L-amino acid-producing ability and modified so that glycerol dehydrogenase and dihydroxyacetone kinase activities are increased, in a medium containing glycerol as a carbon source to produce and accumulate an L-amino acid in the medium or cells, and collecting the L-amino acid from the medium or the cells.

What is claimed is: 
     
         1 . A method for producing an L-amino acid, the method comprising:
 (A) providing a microorganism belonging to the family Enterobacteriaceae having an L-amino acid-producing ability and modified to increase glycerol dehydrogenase and dihydroxyacetone kinase activities,   (B) culturing said microorganism in a medium containing glycerol as a carbon source to produce and accumulate an L-amino acid in the medium or cells, and   (C) collecting the L-amino acid from the medium or the cells.   
     
     
         2 . The method according to  claim 1 , wherein the glycerol dehydrogenase and dihydroxyacetone kinase activities are increased by increasing copy numbers of genes coding for glycerol dehydrogenase and dihydroxyacetone kinase, or modifying expression control sequences of the genes. 
     
     
         3 . The method according to  claim 1 , wherein the dihydroxyacetone kinase uses ATP as a phosphate donor. 
     
     
         4 . The method according to  claim 1 , wherein the microorganism is further modified to increase glycerol uptake activity. 
     
     
         5 . The method according to  claim 1 , wherein the microorganism is further modified to increase activity or activities of an enzyme selected from the group consisting of triosephosphate isomerase, fructose bisphosphate aldolase, fructose-1,6-bisphosphatase, fructose-6-phosphate aldolase, and combinations thereof. 
     
     
         6 . The method according to  claim 1 , wherein the microorganism is further modified to reduce activity or activities of glycerol kinase and/or membrane-binding type glycerol-3-phosphate dehydrogenase. 
     
     
         7 . The method according to  claim 1 , wherein the microorganism belonging to the family Enterobacteriaceae is an  Escherichia  bacterium, or a  Pantoea  bacterium. 
     
     
         8 . The method according to  claim 1 , wherein the L-amino acid is selected from the group consisting of L-glutamic acid, L-lysine, L-leucine, L-isoleucine, L-valine, L-tryptophan, L-phenylalanine, L-tyrosine, L-threonine, L-methionine, L-cysteine, L-arginine, L-serine, L-proline, L-asparatic acid, L-asparagine, L-glutamine, L-histidine, and combinations thereof.