Effect of some nutrients on alginate synthesis in azotobacter vinelandii and characterization of the produced alginate

ABSTRACT

The role of nutrients on alginate production by A. vinelandii was studied in batch cultures. The largest amount of bacterial alginate was obtained in presence of 0.3 g/t MgSO[4-].7H[2]O, 0.4g/l NaCI, 42mg/I CaCl[2]. 2H[2]O, 4mg/I K[2]HPO[4], 16mg/I K[2]HPO[4], 2.5mg/1 FeSO[4-]7H[2]O, 2.9mg/I H[3]BO[3], 2mg/1 ZnSO[4], 7H[2]O, 2mg/I Na[2]MoO[4]. 2H[2]O, 0.3mg/I CuSO[4-],. 5H[2]O, 0.2mg/I MnCI[2]. 4H[2]O. Alginate production was not enhanced by natural additives or inducing agents except for acetate which increase alginate yield. The pure alginate contained 0.36% ash and 0.4% protein. It is similar to algal alginate but has an extra acetyl group. It contains 69.5% M-M block, 27.5% M-G block and 3% G-G block