Genetically Modified Strains of Xanthomonas campestris Higher Xanthan Producer and Capable to Utilize Whey

Xanthomonas campestris is very important industrial microorganism for its ability to produce xanthan gum which has multiple applications. X. campestris was genetically modified to increase its -galactosidase content for subsequent growth on Whey as cheep cultivation medium and concomitant industrial infection of xanthan. Therefore, suicidal plasmid pSUP5011 was mobilized from E. coli to X. campestris by transconjugation to introduce the transposon Tn5. About 126 X. campestris transconjugants Kmr were selected and tested for its ability to produce xanthan gum in whey media. Strain TC 49, the highest xanthan producer transconjugant, was subjected to UV-irradiation for further genetic modification enhancing xanthan over production. About 45 mutants were selected and tested for their ability to produce xanthan in whey media. A new genetically modified mutant, Tn-UV-2 proved to be the best xanthan producer in lactose or whey media. Produced xanthan gum was characterized chemically using Fourier Transform Infrared (FTIR) spectra and was found to have the same FTIR spectral peaks of xanthan gum produced commercially.