Production of extra-cellular polymer in Azotobacter and biosorption of metal by exopolymer

Abstract

Two Azotobacter strains were isolated from alkaline and acid soils. The production of alginate and exopolymer from these two strains showed that, strain AC2 produced high polymer in 2% beet molasses or 1% sucrose broth and addition of nitrogen sources (yeast extract) reduced production of this polymer. The optimum condition for production of maximum polymer production (7.5 mg/ml) was at 200 rpm shaking, pH 7 without addition of nitrogen sources. The production of polymer was reduced at pH 4. The polymer adsorbed Cu, Zn, and Fe, at 15.5, 20 and 25 mg, respectively.

Key Words: Azotobacter, exopolymer, of extracellular polysaccharide, biosorption of metal.

African Journal of Biotechnology Vol.3(6) 2004: 330-333