Xanthan gum production from grape pomace using different Xanthomonas bacteria

In this study, the wine industry, which is one of the agricultural by-products, and the grape pomace which are produced as waste in the grape process; is intended to be used in the production of xanthan gum, which is a product with high added value and wide usage area. In the scope of the research; xanthan gum production was performed by fermentation using the strains Xanthomonas campestris DSM 19000, Xanthomonas axonopodis pv. vesicatoria, Xanthomonas hortorum pv. pelargonii ve Xanthomonas axonopodis pv. begoniae. Xanthan gum production was carried out at 28 ℃ with 72 hours of fermentation at 220 rpm mixing speed, glucose concentration was %4 and inoculum ratio was %5. The average amount were determined to be 4.81 g/L using X. campestris DSM 19000 (NRRL B-1459), 5.98 using X. hortorum pv. using pelargonii, 6.25 with X. axonopodis pv. vesicatoria, and 5.15 with X. axonopodis pv. begoniae. The X. axonopodis pv. vesicatoria strain was found to produce xanthan gum in higher amount than the standard strain X. campestris DSM 19000 (NRRL B-1459). Xanthan gum yields were determined as %12 with X campestris DSM 19000, % 14.9 with X. hortorum pv pelargonii, % 15.6 with X. axonopodis pv. vesicatoria and % 12.8 with X. axonopodis pv. begoniae depending on the average xanthan gum amounts obtained. The gum-water solutions of the acquired gums were prepared and various rheological analyzes were made by rheometer with the addition of pudding as the model food. The highest viscosity value was determined in the gam-water mixture obtained from the strain X. hortorum pv. pelargonii. The viscoelastic properties of the aqueous solutions of the gums are similar. When the pudding samples obtained from the produced gums are examined rheologically, the highest consistency is the X. axonopodis pv. begoniae strain. During xanthan gum production, fermentation kinetics were examined and an increase in the amount of gum and amount of biomass was observed depending on the production of xanthan gum, while the rate of glucose decreased continuously up to 96 hours. In general, although the yields obtained in the study are not very high, it is thought that efficiency can be increased by optimizing production conditions. The use of various wastes in the production of xanthan gum has an important place both ecologically and economically.