Studies on Morphological, Physiological and Biochemical Characterization Azospirillum Spp

Asymbiotic, associative, or symbiotic, Nitrogen fixing strains of Azospirillum isolated from Rhizosphere soils of paddy field. Totally 30 Azospirillum strains were isolated from paddy field of Thanjavur District by using Nitrogen free bromothymol blue (Nfb) medium. The isolated strains were characterized by physiological, morphological and biochemical characteristics and construct the phylogenetic tree. Based on this characterization, among the 30 isolates, nine belonged to A. halopraferens, 8 belonged to A. amazonense, 6 belonged to A. brasilense, 4 belonged to A. lipoferm and 3 belonged to A. irakense.