PRODUCTION OF XANTHAN GUM BY SPHINGOMONAS BACTERIA CARRYING GENES FROM XANTHOMONAS-CAMPESTRIS

Twelve genes coding for assembly, acetylation, pyruvylation, polymeriz ation, and secretion of the polysaccharide xanthan gum are clustered t ogether on the chromosome of the bacterium Xanthomonas campestris, The se genes (gumBCDEFGHIJKLM) are sufficient for synthesis of xanthan gum when placed in bacteria from a different genus, Sphingomonas. The pol ysaccharide from the recombinant microorganism is largely indistinguis hable, structurally and functionally, from native xanthan gum, These r esults demonstrate that a complex pathway for biosynthesis of a specif ic polysaccharide can be acquired by a single inter-generic transfer o f genes between bacteria, This suggests the biological and commercial feasibility of synthesizing xanthan gum or other polysaccharides in no n-native hosts.