Investigation of cellular fatty acid composition of Xanthomonas spp. as chemical markers of productivity and quality of xanthan gum

In this study, we investigated the cellular fatty acid profiles of different Xanthomonas pathovars producing xanthan gum and explored the fatty acid composition to identify chemical markers of xanthan gum productivity and quality. Three Xanthomonas pathovars were studied. The fermentation was conducted for 168 h. Samples from the fermented medium were collected for extraction, quantification, and characterization of xanthan. The unsaturated/saturated (U/S) fatty acid ratio in Xanthomonas cells during fermentation was correlated with production, viscosity, and molecular weight of the gum obtained at each 24 h. The Xanthomonas axonopodis pv manihotis 290 strain showed a higher U/S ratio for major cell fatty acids (C16:1ω7/C16:0) as compared with the other two strains; this high ratio was directly associated with xanthan production. No correlation was observed between cellular fatty acid composition and characteristics of xanthan synthesized. Thus, it was possible to determine a production chemical marker for xanthan gum in Xanthomonas strains.