Novel Escherichia coli having accession no. PTA 1579 and its use to produce polyhydroxybutyrate

Abstract

The present invention provides a novel genetically modified Escherichia coil JM109 bearing accession number PTA 1579, containing the gene coding for poly-beta-hydroxybutyrate synthesis and a method of using this bacterium to produce poly-beta-hydroxybutyrate to the extent of 60% or more of the cell weight.

1 - 5 . (canceled)  
     
     
         6 . A method for producing poly-beta-hydroxybutyrate, said method comprising: 
 (i) isolating a nucleic acid encoding the proteins responsible for poly-beta-hydroxybutyrate synthesis from  Streptomyces aureofaciens  NRRL2209,    (ii) cloning said nucleic acid into a plasmid vector to obtain a recombinant vector,    (iii) transforming  Escherichia coli  with said recombinant vector to obtain recombinant  Escherichia coli  which expresses said proteins responsible for poly-beta-hydroxybutyrate synthesis, and    (iv) culturing said recombinant  Escherichia coli  in a conventional medium comprising glycerol and one or more substrates, and    (v) recovering said poly-beta-hydroxybutyrate.    
     
     
         7 . The method according to  claim 6  wherein the nucleic acid encoding the proteins responsible for poly-beta-hydroxybutyrate synthesis is a 4.826 Kb fragment.  
     
     
         8 . (canceled)  
     
     
         9 . A method as claimed in The method according to  claim 6  wherein the plasmid vector is a multicopy plasmid vector.  
     
     
         10 . The method according to  claim 6  wherein the recombinant plasmid vector is pSa240.  
     
     
         11 . The method according to  claim 10  wherein the  Escherichia coli  is transformed at a temperature in the range of 14°-18° C. in the presence of T4 DNA ligase enzyme.  
     
     
         12 . (canceled)  
     
     
         13 . The method according to  claim 6  wherein the hydroxybutyrate is produced in recoverable quantities of at least about 60% (w/w) of the recombinant  E. coli  dry cell mass.  
     
     
         14 . The method according to  claim 6 , wherein the nucleic acid comprises the sequence of SEQ ID NO. 1.  
     
     
         15 . The method according to  claim 9 , wherein the multicopy plasmid vector is pGEM-3Z.