Biosynthesis of 2 keto-L-gulonic acid

Abstract

A process of producing 2-keto-L-gulonic acid from sorbose via a recombinant bacteria including expression vectors and probes for producing said recombinant bacteria.

We claim: .[.1. A gluconobacter transformed with Tn5 which inactivates the 2-keto-L-Gulonic acid reductase and further having a recombinant plasmid which plasmid contains the DNA sequence effecting expression of L-sorbose dehydrogenase so that L-sorbose is converted to 2-KGA..]. .[.2. A gluconobacter transformed with Tn5 which inactivates the 2-keto-L-Gulonic acid reductase and which naturally produces L-sorbosone dehydrogenase but 
     
        not L-sorbose dehydrogenase..]. .[.3.  The Gluconobacter of claim 1 wherein said recombinant plasmid is a plasmid RSF1010 modified to contain DNA encoding L-sorbose dehydrogenase..]. .Iadd.4. A transformed gluconobacter which has been obtained from a gluconobacter which produces L-sorbosone dehydrogenase but not L-sorbose dehydrogenase wherein said transformed gluconobacter: 1) had been transformed with Tn5 which inactivates the 2-keto-L-gulonic acid reductase, and   2) has a recombinant plasmid which plasmid has been modified to contain a DNA sequence from the L-sorbose dehydrogenase gene region of Gluconobacter oxydans UV10 (Accession Number FERM BP-1267) wherein said DNA sequence is selected from the group consisting of pUR H80, pUR 010, and uPR P88;   so that L-sorbose is converted to 2-keto-L-gulonic acid. .Iaddend. .Iadd.5. The gluconobacter of claim 4 wherein said recombinant plasmid is plasmid RSF1010 modified to contain said DNA sequence. .Iaddend.