| Abstract [eng] |
The natural polysaccharide alginate is one of the most widely used biopolymers due to its unique properties. The ability to form gels, biocompatibility with other substances, physicochemical properties and biological activity determine the wide use of alginate in the medical, pharmaceutical, food, cosmetic and textile industries. The production of alginate by fermentation from Azotobacter vinelandii bacteria is becoming an important research object in order to commercialize microbial polymers. High production costs are one of the main factors limiting the application of alginate production from bacteria on an industrial scale. Various studies have established that the use of secondary raw materials as a carbon source, control of fermentation parameters and genetic engineering methods can effectively reduce production costs and increase the concentration of the produced product. Biotechnological production of alginate was carried out using gram-negative Azotobacter vinelandii bacteria, fermentation was carried out for 72 hours. During the conducted research, the influence of fermentation duration and nineteen different carbon sources on bacterial biomass and alginate concentration was investigated, the concentration of reducing sugars was determined, the antioxidant activity of the produced alginates was evaluated, FT-IR spectra were drawn to identify the structure of alginate. Among the studied traditional and alternative carbon sources, the highest concentration (1.51 g/L) of alginate after 24 hours of fermentation was obtained when lemon peel hydrolysate was used as a carbon source in the nutrient medium. The results of the antioxidant activity of the produced alginates by FRAP and the reduction method showed that the highest antioxidant properties, respectively 8.73 μmol/L and 0.30 o.u., were characteristic of alginate when apple peel hydrolysate was used as a carbon source. |
