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Vol. 29 (2026 year), No. 3, DOI: 10.21443/1560-9278-2026-29-3

Yamashev T. A., Khusainov I. A., Kruchina-Bogdanov I. V., Naumov I. A., Kanarsky A. V.
The influence of carbon source and cultivation conditions on the synthesis of xanthan gum by Xanthomonas campestris bacteria VKPM B-6720 and its properties

Xanthan gum biosynthesis has been performed using the Xanthomonas campestris bacterial strain VKPM B-6720, sucrose, and glucose contained in molasses and wheat hydrolysate respectively. Cultivation has been carried out in flasks in a shaker incubator and in a forced-air aeration system. Carbohydrate consumption, the amount of xanthan formed, pH, and viscosity of the culture fluid have been measured during the cultivation. More xanthan is formed during cultivation in a medium containing glucose as the main carbon source; the viscosity of the culture fluid is higher than during cultivation in media containing sucrose. The economic coefficient for cultivation in glucose-containing media is 0.24 (in flasks) and 0.40 (in a forced-air aeration system), while for sucrose-based media it is 0.18 and 0.28, respectively. The study has determined the final viscosity of glucose-based media [14.6 (in flasks) and 45.2 mPa•s (in a forced-aeration unit)] and sucrose-based media (7.25 and 37.4 mPa•s, respectively). Culture media based on molasses and wheat hydrolysate remained neutral during the first two days.On the third day, the molasses-based media became acidic, while the wheat hydrolysate-based media became alkaline. On the fourth day, the pH of the molasses-based media became alkaline (due to cell death and autolysis). Xanthan gum obtained from molasses is darker in color than that obtained from wheat hydrolysate. The carbohydrate composition of xanthan gum determined by gas chromatography is similar to that of the commercial product. The viscosity of 1 % xanthan gum solution obtained in the laboratory is three times lower than that of the commercial sample. Laboratory xanthan gum contains more impurities as evidenced by its high ash content and the results of elemental analysis obtained by scanning electron microscopy.

(in Russian, стр.16, fig. 7, tables. 4, ref 46, AdobePDF, AdobePDF 0 Kb)