Screening and evaluation of the alginate production potential of Azotobacter from soil in Kerman province

Introduction and Objectives: Azetobacter is one of the most important nitrogen stabilizing bacteria to form a heteropolysaccharide capsule of alginate to protect its nitrogenase enzyme against oxygen. Alginate is widely used due to viscosity, water absorption and elasticity in medicine, food industry, pharmacy, printing industry, paper and even bio-absorption of heavy metals. The purpose of this study was to isolate Azotobacter alginate producers from soil in Kerman province. Materials and methods: 80 samples of agricultural, pasture and forest soils were collected in five districts of Kerman province by cluster samplingFrom the surface to a depth of 10 cm. Initially Azetobacter was confirmed using the specific culture media of Manitol agar and Browne N-Free agar and the morphology of the colonies. Then, in order to evaluate the potency of alginate production, strains tested in carbazole solution were used in borate and borate-free conditions. The intensity of the purple color indicated a higher amount of alginate produced by spectrophotometry. Results: Totally, 38 Azotobacter strains were identified. Of the strains mentioned, 23 strains had the ability to produce alginate. Most of the Azotobacter strains of Alginate originate in the cities of Baft (47.43%), Kerman (30.43%), Jiroft (8.69%), Sirjan (8.69%) and Bam (4.43%), respectively. Conclusion: The results of this research showed that the soils of different crop areas with moderate climate in Kerman province have a significant potential for separating alginate generators. Therefore, further research, such as chemical analysis, optimization, purification of alginate, and identification of molecular identity of superior strains, are suggested.

کلیدواژه ها:

Azotobacter ، Alginate ، Carbazolem ، Soil