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

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

Alginate production by azotobacter Vineland

The production of alginate by a mucoid strain of Azotobacter vinelandii was studied in batch culture. Highest alginate yield was obtained using Jarman N 2,-free mineral medium supplemented with 4% sucrose and the pH was initially adjusted to 8.0. Maximum alginate yield and productivity were achieved at the late growth phase [4 days old cultures], when each flask containing 100m1 medium was inoculated with 5% [V/V] bacterial suspension of 36h old cultures and shaked at 250rpm