†Center of Marine Biotechnology, Maryland Biotechnology Institute, University of Maryland, Baltimore, MD 21202, USA.
Increase of xanthan production by cloning xps genes into wild-type Xanthomonas campestris
Article first published online: 28 JUN 2008
Letters in Applied Microbiology
Volume 14, Issue 2, pages 43–46, February 1992
How to Cite
Tseng, Y.-H., Ting, W.-Y., Chou, H.-C., Yang, B.-Y. and Chen, C.-C. (1992), Increase of xanthan production by cloning xps genes into wild-type Xanthomonas campestris. Letters in Applied Microbiology, 14: 43–46. doi: 10.1111/j.1472-765X.1992.tb00643.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- received 3 October 1991 and accepted 8 October 1991
Previously, genomic banks of Xanthomonas campestris were constructed in Escherichia coli, using mobilizable broad-host-range cosmids as the vectors. Following conjugal transfer, genes involved in the biosynthesis of xanthan polysaccharide (XPS) were cloned by the ability to restore the mucoid phenotype to the non-mucoid mutants. In this study, all clones were transferred into the wild-type strain Xc17 to evaluate the effects of the cloned genes on XPS production. Most clones showed no significant effect; however, two plasmids, pP2401 and pP2201, caused 10 and 15% yield increases, respectively, compared with that of controls. While it was not clear how pP2201 caused the yield increase, the effect of pP2401 seemed to result from elevated phosphomannose isomerase activity. Since XPS synthesis in X. campestris is a very efficient process, only relatively small increases are to be expected; an enhancement of productivity by 10–15% is important to the commercial production of xanthan.