| Abstract [eng] |
Xanthan is a microbial polysaccharide, composed of D-glucose, D-mannose and D-glucuronic acid residues in a ratio of 2:2:1 and variable proportions of O-acetyl and pyruvyl residues. This biopolymer has exceptional physical properties - dissolves in both cold and hot water, even in low concentrations xanthan forms high viscosity solutions, which are stable in high variations of pH, temperature and salt concentration. In this project there was made optimisation research of xanthan synthesis by Xanthomonas campestris. There were used 9 different carbon sources, from which 2 are considered to be alternative - glycerol and coconut tree sugar. Also there were used 4 different solvents. The highest xanthan yield obtained when using maltose as a substrate – 11.06 g/l. Coconut palm sugar as alternative carbon source is better choice for xanthan production than glycerol. In all cases the results show that acetone fits the best for xanthan precipitation and the methanol on the contrary. |
