ISOLATION OF WILD XANTHOMONAS STRAINS FROM AGRICULTURAL PRODUCE, THEIR CHARACTERIZATION AND POTENTIAL RELATED TO POLYSACCHARIDE PRODUCTION

One hundred fifty wild strains of Xanthomonas were isolated on five se lective and nonselective media. The comparative effectivity of the fiv e media has been discussed. Fifteen polysaccharide-producing strains s hortlisted were identified up to species level. These were studied for polysaccharide production in shake flasks using YM media. The highest final yield of 21.3 g/L of the amount of carbon source supplied has b een obtained in the optimum medium in shake-flask experiments from Xan thomonas campestris ICa-125 strain isolated from cabbage. Rheological properties of the exocellular polysaccharide (EPS) have been compared with standard xanthan. EPS from X. campestris ICa-125 was found to be superior with respect to heat stability and effect of electrolytes as compared to standard xanthan.