RECOMBINANT DNA PLASMID FOR XANTHAN GUM SYNTHESIS

摘要

TITLE OF INVENTION RECOMBINANT DNA PLASMID FOR XANTHAN GUM SYNTHESIS Described is a DNA fragment containing some essential genetic material for xanthan gum synthesis. The fragment is isolated from gum-producing Xanthomonas campestris and inserted into a cloning vector using recombinant DNA technology. A resulting recombinant plasmid, pCHC3, restores xanthan gum synthesis to non-xanthan gum forming (non-mucoid) mutants, increases xanthan gum yield in gum-producing strains by gene augmentation, and increases the pyruvate content of the obtained xanthan gum. The invention encompasses other DNA fragments isolated from gum-producing X. campestris and which, after appropriate manipulations, restore xanthan gum synthesis in substantially the same fashion as the fragment of pCHC3.