Xanthan gum production and rheological behavior using different strains of Xanthomonas sp.

The proposal of the present study was to select and carry out the molecular characterization of strains of Xanthomonas sp. in order to correlate with gum production and determine possible genetic alterations during the study. The gums produced were also evaluated rheologically. Ten strains of Xanthomonas were used in the screening and the best ones in terms of productivity were Xanthomonas campestris pv. mangiferaeindicae 1230 (8.93 g/L), X. campestris pv. campestris 254 (9.49 g/L) and X. campestris pv. campestris 1078 (9.67 g/L). The gum produced by X. campestris pv. mangiferaeindicae presented the best apparent viscosity. The results for the profiles of the bands produced by RAPD showed considerable genetic variability amongst the evaluated strains, making not possible to neither group the strains according to pathovar or species, nor correlate the band profile with the productivity obtained. According to the RAPD analysis, no detectable mutations occurred in these bacteria during the study.