Sugarcane Juice Fermentation for Alginate Production by Azotobacter vinelandii

Abstract

Alginate production by Azotobacter vinelandii ATCC 9046 using sugarcane juice (approximate content of sucrose 10 g/L) as a main carbon source was investigated by altering pH-controlled values at 5.59, 6.00, 7.00, 8.00, and 8.41 and nitrogen concentrations using 0.02, 0.10, 0.30, 0.50, and 0.58 g/L yeast extract. The maximum biomass concentration was strongly affected by the nitrogen content in the sugarcane juice medium, while both the nitrogen content and the controlled pH of the medium influenced the alginate production (P<0.05). However, their interaction effect was not determined for both the biomass and the alginate productions. The highest alginate concentration was achieved under the culture at the pH-controlled value of 6.0 and nitrogen concentration of 0.10 or 0.50 g/L as 6.89±0.98 and 7.29±0.10 g/L, respectively. Moreover, it was found that the molecular weight of the obtained alginate was affected by the initial concentration of nitrogen in the culture. The data from this research suggested that the culture under pH 6.0 and 0.1 g/L nitrogen was suitable for alginate production by A. vinelandii ATCC 9046 using sugarcane juice as a carbon source due to high alginate production.