| Abstract [eng] |
The study is aimed at increasing the cost-effectiveness and environmental friendliness of the xanthan production process by studying different carbon sources and evaluating the properties of the obtained xanthan. This work examined 20 different carbon sources that could be applied in the production of xanthan from Xanthomonas campestris bacteria as a cheaper alternative. 13 of these sources are considered alternative because they are obtained as by-products. The efficiency of the process and the suitability of carbon sources for Xanthomonas campestris bacteria were evaluated by determining the concentrations of extracted xanthan and biomass after 24 h, 48 h and 72 h of fermentation. Also, during the entire process, light absorption at 600 nm wavelength was measured at the initial time point and after 24 h, 48 h and 72 h of fermentation to evaluate the fermentation process. According to the obtained xanthan concentrations, the highest yields were achieved in media with xylose after 24 h (27.20 g/L), with coconut palm flower sugar after 48 h (26.37 g/L), hydrolysate of avocado peels after 24 h (26.11 g/L) of fermentation. Extracted xanthan using different carbon sources was used for property research. During the studies, the reducing properties of xanthan were determined. Generally, commercial xanthan is not considered as a good antioxidant. After 2 different methodical research for the determination of reducing properties, it was found that xanthan obtained from a medium with sugar from coconut palm blossoms has not only a high yield, but also the highest reducing properties. For quality determination, FT-IR spectroscopy was done to compare selected samples with commercial xanthan. During the studies on the use of xanthan, the ability of xanthan in combination with gelatine to form hydrogels was determined, which would produce a transparent film after drying. Also, xanthan was evaluated as a replacement for agar in the production of nutritional media. Broccoli seeds have sprouted on these media and showed positive characteristics: lush and large leaves. Thus, to produce xanthan from Xanthomonas campestris bacteria, it is recommended to use the sugar carbon source of coconut palm blossoms and carry out the fermentation for 48 hours, maintaining the temperature at 37 °C. The successful results obtained in the use of xanthan studies provide a strong basis for further research on xanthan samples. Gelatine-xanthan hydrogels can be tested for 3D bioprinting, and studies of xanthan as an agar substitute can test larger amounts of xanthan samples. |
