Process for producing 2-keto-L-gulonic acid

Abstract

2-Keto-L-gulonic acid is prepared from 2,5-diketo-D-gluconic acid through microbial conversion. The 2-keto-L-gulonic acid producing microorganism used for this microbial conversion includes strains which belong to genera of Brevibacterium, Arthrobacter, Micrococcus, Staphylococcus, Pseudomonas and Bacillus. Both the incubation of the microorganism in a medium containing 2,5-diketo-L-gluconic acid and the direct contact of any products obtained from the cells with a substrate containing said 2,5-diketo-D-gluconic acid may be used in the disclosed process.

What is claimed is: 
     
       1. A process for producing 2-keto-L-gulonic acid or a salt thereof which comprises; contacting a 2-keto-L-gulonic acid producing strain selected from microorganisms which belong to the genera of Brevibacterium, .[.Arthrobacter,.]. Bacillus, Staphylococcus, Micrococcus and Pseudomonas, with 2,5-diketo-D-gluconic acid or a salt thereof, under conditions sufficient to produce 2-keto-L-gulonic acid, and recovering the produced 2-keto-L-gulonic acid or any salts thereof from the resultant mixture. 
     
     
       2. A process as claimed in claim 1, wherein the 2-keto-L-gulonic acid producing strain is incubated in a medium containing 2,5-diketo-D-gluconic acid or a salt thereof to effect a fermentative action therein, and recovering 2-keto-L-gulonic acid or any salts thereof accumulated during the incubation from the medium. 
     
     
       3. A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Brevibacterium. 
     
     
       4. A process as claimed in claim 3, wherein said strain belongs to Brevibacterium ketosoreductum. .[. 
     
     
       5.  A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Artheofacter..]. 
     
     
       6. A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Bacillus. 
     
     
       7. A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Staphylococcus. 
     
     
       8. A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Micrococcus. 
     
     
       9. A process as claimed in claim 2, wherein said 2-keto-L-gulonic acid producing strain belongs to the genus of Pseudomonas. 
     
     
       10. A process as claimed in claim 1, wherein cells of said microorganism strain are contacted with a substance containing 2,5-diketo-D-gluconic acid or a salt thereof under conditions sufficient to produce 2-keto-L-gulonic acid, and the 2-keto-L-gulonic acid or any salts thereof produced and accumulated as a result of the contact are recovered from the resultant mixture. 
     
     
       11. A process as claimed in claim 1, wherein an aqueous medium containing viable cells of said microorganism is contacted with a substance containing 2,5-diketo-D-gluconic acid or a salt thereof. 
     
     
       12. A process for producing 2-keto-L-gulonic acid or a salt thereof which comprises cultivating 2-keto-L-gulonic acid producing microorganisms selected from the group consisting of Brevibacterium ketosoreductum, .[.Arthrobacter simplex,.]. Bacillus megaterium, Staphylococcus aureus, Micrococcus dinitrificans, Micrococcus rubens, Micrococcus roseus and Pseudomonas chlororaphis, and mutants thereof, in an aqueous nutrient medium in the presence of 2,5-diketo-D-gluconic acid or a salt thereof, and recovering the produced 2-keto-L-gulonic acid or salts thereof from the resultant mixture. 
     
     
       13. A process as claimed in claim 12, wherein said microorganism is Brevibacterium ketosoreductum ATCC 21914. .[.14. A process as claimed in claim 12, wherein said microorganism is Arthrobacter simplex ATCC 
     
     
        21917..]. 15. A process as claimed in claim 12, wherein said microorganism 
     
     
        is Bacillus megaterium ATCC 21916. 16. A process as claimed in claim 12, wherein said microorganism is Staphylococcus aureus ATCC 21915.