| abstract |
A recombinant-DNA mediated method for the synthesis of sugar nucleotides. This method utilizes portable DNA sequences capable of directing the microbial synthesis of various enzymes that catalyze the synthesis of sugar nucleotides, including UDP-glucose, UDP-glucuronic acid and GDP-mannose. The sugar moieties of these sugar nucleotides may subsequently be incorporated into industrially-useful polysaccharides such as xanthan gum. It has been found that vectors containing the portable DNA sequences described herein are capable both causing sugar nucleotide production in microorganisms previously incapable of such synthesis and of causing increased sugar nucleotide production in organisms capable of synthesizing small quantities of these compounds. In particular, plasmids pAS7, pAS9 and pTS13 are disclosed. These plasmides are capable of directing sugar nucleotide synthesis in various hosts, including Xanthomonas sp. such as X.campestris and other organisms such as E.coli and various Pseudomonas sp. |