Response of Azospirillum brasilense to Application of Co and Mo-salts in Free-living culture and its Impact on Growth and Enzymes of Nitrogen Metabolism
Lodh Anuradha, Srivastava Ramesh C.*
Plant Physiology and Biochemistry Research Laboratory Department of Botany, Tripura University, Suryamaninanagar–799 130, Tripura, India.
*Corresponding author, E-mail: email@example.com
Azospirillum brasilense, a free-living nitrogen-fixing micro-organism, is being popularized now-a-days to be used as bio-fertilizer for many cereal crops plants. Before using this bio-fertilizer, one should check its potentiality in terms of growth, nitrogenfixing efficiency and nitrate-utilizing capacity so that cereal crops get sufficient benefit. In this regards, Azospirillum brasilense was cultured in the medium prescribed by IMTECH, Chandigarh. But, using certain ingredients especially the micronutrients of defined Bergerson's (1976) medium the growth and other enzymes of nitrogen metabolism of Azospirillum brasilense, were triggered. Thus by using different concentration of micronutrients like Cobalt Chloride (Co) and sodium molybdate (Na2MoO4) in addition to the nutrient ingredients prescribed by IMTECH, to the culture broth increased the growth, viable counts, nitrogenase (N2-ase) activity and nitrate reductase (NR) activity of the Azospirillum brasilense in cell-free culture. Our findings revealed that if we use some other beneficial micronutrients as the source of Co and Mo in the medium prescribed by IMTECH, we get vigorous growth of Azospirillum brasilense in cell-free culture. Possibly these triggered bacteria would prove much better in respect of nitrogen-fixation in field with roots of cereal plants.