Production and characterization of the polysaccharide xanthan gum by a local isolate of the bacterium Xanthomonas campestris

摘要

A local isolate of the bacterium?Xanthomonas campestris?was obtained from infected cabbage leaves. Microbiological and biochemical tests were made to confirm its identification. The isolate was coded as?X. campestris?MU1. Growth and xanthan production reached their highest levels (1.65 and 5.41 g/l) after 7 and 8 days of incubation, respectively, in a chemically defined medium. Sucrose was shown to be the best carbon source for xanthan production. Thin layer chromatography of the produced xanthan showed that, it composed glucose, mannose and glucouronic acid, in addition to pyruvic and acetic acids. The results indicate that,?X. campestrisMU1 is very much related to?X. campestris?NRRL-B 1459.