Obele, Ishaya IsaMakut, M.D.Akwashiki, OmbugaduOwuna, GabrielEt el2023-12-142023-12-142019-08-05[1] Tilak, K. V. B. R., Ranganayaki, N., Pal, K. K., De, R., Saxena, A. K., Shekhar, Nautiyal, C., Shilpi Mittal, Tripathi, A. K., and Johri, B. N., (2005). Diversity of plant growth and soil health supporting bacteria. Current science, vol. 89, p: 136-143. [2] Nautiyal SC, Mehta S, (2001). An efficient method for qualitative screening of phosphate-solubilizing bacteria. Current Microbiol. 43: 51-56. [3] Venkateswarlu, B., Balloli, S. S., Ramakrishna, Y. S., (2007). Organic farming in rain fed Agriculture. Central research institute for dry land agriculture, Hyderabad, p: 88. [4] Qureshi M. A., Ahmad M. J., Naveed M., Iqbal A., Akhtar N. and Niazi K. H. (2009). Co-inoculation with Mesorhizobium ciceri and Azotobacter chroococcum for improving growth, nodulation and yield of chickpea (Cicerarietinum L.). Soil & Environ. 28(2), p: 124-129. [5] Postgate J. (1998). Nitrogen fixation-3rdEd., Cambridge University press, Cammbridge, U. K. [6] Pareek, R. P, Chandra R. and Pareek N. (2002). Role of BNF technology in sustainable agriculture-Proceeding of National Symposium (eds. Masood, A., Chaturvedi S. K and Gurha S. N), Indian Institute of Pulses Research, Kunpur, p. 33-42. [7] Appanna V D, Gazso L G, StPierre M (1996) Multiple metal tolerance in Pseudomonas fluorescens and its biotechnological significance. J Biotechnol 52: 75-80. [8] Dobereiner J, (1999). Nonsymbiotic nitrogen fixation in tropical soils. In: Biology and ecology of nitrogen. Proceeding of a Conference National Academy of Science, Washington D. C. [9] Aquilanti, L., Favilli, F. & Clementi, F. (2004). Comparison of different strategies for isolation and preliminary identification of Azotobacter from soil samples. Soil. Biol. Biochem., 36: 1475-1483. [10] Singh S, Chandra R, Patel DK, Rai V (2007). Isolation and characterization of novel Serratia marcescens (AY927692) for pentachlorophenol degradation from pulpand papermill waste. World J Microbial Biotechnol 23: 1747-1754ss. [11] Sathish Kumar S. R and Bhaskara Rao K. V (2012). A review of Biological Nitrogen Fixation, Molecular and Microbiologyhttps://keffi.nsuk.edu.ng/handle/20.500.14448/5836Free living nitrogen fixing bacteria are those that lives freely on rhizosphere of a young growing plant or those living in a close association with root of plants (Rhizobacteria) but not symbiotically. In most tropical soil, Nitrogen and other essential nutrients element are the most limiting nutrients which deficiencies could lead to slow growth and reduced crop production. Free living nitrogen fixing bacteria has the potential of secreting nitrogenase enzymes and produces organic acids such as glycolic, acetic, malic, succunic acids which fix atmospheric nitrogen directly into the soil for plants growth and development. To this end, the study on isolation, identification and screening of Azotobacter chroococcum from soil of Keffi, Nasarawa State, Nigeria was carried out from May to September 2018. Soil samples were collected from eight different locations and Azotobacter strains were isolated and identified using standard microbiological methods. The 16SrRNA gene sequence analysis of the strain showed maximum similarity of 96% with Azotobacter chroococcum of the reference type strain deposited in RDP Gen Bank database. Azotobacter strains isolated from four different locations showed coloured zone ranging between 16-10mm. Similarly, Percentage amount of nitrogen released by each Azotobacter strain in the culture broth ranging between 1.19% - 5.11% in an increasing order.enRhizobacteria, Azotobacter chroococcum, 16SrRNA Sequencing, Nitrogen-free Agar, Nitrogen-free Broth, Bio-fertilizerArticle