##plugins.themes.bootstrap3.article.main##

Sandeep Upadhyay Narendra Kumar V. K. Singh Anshuman Singh

Abstract

Among the diazotrops, great attention has been paid to the genus Azotobacter and its role in increasing the growth and health of plants. In the present study, forty two strains of Azotobacter were isolated from soil. These strains were purified and characterized through microscopical and biochemical test for cell shape, pigmentation, colony size, Gram reaction and catalase activity were identified as Azotobacter sp These strains showed wide variability to these characters. Among 42 isolates, 7 were single cocci, 7 coccidal chain and 4 were cocci in clumps. Majority of isolates i.e. 24, were small, medium and large rod shaped. Thirty two isolates were Gram –ve, catalase positive and 10 were Gram +ve, catalase negative. Finally from these isolates, twenty two were confirmed as Azotobacter strains on cyst formation. The carbon-source utilization pattern revealed that out of 22 strains that 16 strains resembled the characters of A. chroococcum, 3 matched with A. vinelandii and 3 with A. beijerinckii. All 22 isolates were analyzed for its nitrogen fixing ability by using Microkjeldhal method. The highest amount of N2 (18.88 mg g-1 sucrose) was fixed by Azo-SBT 72 while lowest (6.04 mg g-1 sucrose) by Azo-SUR 25 strain. However, injudicious and hazardous use of chemical fertilizers have degraded the soil health and there is need of ecofriendly management of soil by screening and hunting of potential nitrogen fixing strains to protect the soil environment and health. In this context, biofertilizers hunting natural environment is the need of soil to ensure better health of future generations.

Downloads

Download data is not yet available.

Metrics

Metrics Loading ...

##plugins.themes.bootstrap3.article.details##

##plugins.themes.bootstrap3.article.details##

Keywords

Azotobacter isolates, Catalase activity, Cyst formation

References
Ahmad, F, Ahmad, I. and Khan, M.S. (2008). Screening of free-living rhizospheric bacteria for their multiple plant growth promoting activities. J. Microbiol. Research. 163: 173-181.
Aquilanti, L., Favilli, F. and Clementi, F. (2004). Comparison of different strategies for isolation and preliminary identification of Azotobacter from soil samples. Soil Biol. Biochem., 36: 1475-1483.
Banerjee, S. (1977). Morphological and physiological characteristics of different strains of Azotobacter isolated from soils of Nainital tarai. Pantnagar J. Res., 2(2): 262.
Becking, J.H. (1992). The family Azobacteraceae, 2nd ed, Springer, Verlag, Berlin, pp. 3144–3170.
Brock, T.D., Madigan, T.M., Martinko, J.M. and Parker, J. (1994). Biology of Microorganisms. 7th ed. Prentice Hall International, Inc., USA. p. 142.
Cerney, G. (1993). Method for the distinction of gram negative and gram positive bacteria. EU J. Appl Micro. (3), 223-225.
Holt, J.G. and Krieg, N.R. (ed.) (1984). Bergey’s Manual of Systematic Bacteriology, vol. 1. Wiliams and Wilkins, Baltimore, Md, pp 219.
Islam, M.Z., Sharif, D.I. and Hossain, M.A. (2008). A comparative study of Azotobacter spp. from different soil samples. J. Soil Nature. 2(3): 16-19.
Jackson, M.L. (1967). Soil chemical analysis. Prentice Hall of India Pvt. Ltd., New Delhi. pp. 263-293.
Jensen, H.L. (1955). Non-symbiotic nitrogen fixation In: Soil nitrogen (eds.) Barthdlomew, W.V. and Clark, F. E. American Soc. Agron. Inc. Madison, 10: 436-480.
Jimenez, J.D., Montana, J.S., Martínez, M.M. (2011). Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils. Braz. J. Microbiol. 42(3) 66-78.
John, G.H., Noel, R.K., Peter, H.A.S., James, T.S. and Stanley, T.W. (1994). Aerobic/ microaerophilic, motile, helical/vibroid Gram negative bacteria. In: Bergey’s Manual of Determinative Bacteriology. p. 39–45. USA: Lippincott Williams & Wilkins.
Khalid, A., Arshad, M. and Zaheer, Z.A. (2004). Screening plant promoting rhizobacteria for improving growth and yield of wheat. J. Appl. Microbiol., 96: 473-480.
Krieg N.R., Holt J.G., Sneath P.H.A., Staley J.T., and Williams S.T. (1994). Bergey’s Manual of Determinative Bacteriology (9th ed.), Williams & Wilkins, Baltimore, Md, USA.
Mahmoud, S.A.Z., El-Sawy, M., Ishac, Y.Z. and El-Safty, M.M. (1978). The effects of salinity and alkalinity on the distribution and capacity of N2 fixation by Azotobacter in Egyptian soils. Ecol. Bull. NFR (Naturvetensk. Forskningsradet) 26: 99-109.
Narayan, R.P. and Kehri, H.K. (2011). Effect of different agricultural practices on population dynamics of Azotobacter chroococcum and its nitrogen fixing potentiality in Trans- Ganga and Trans-Yamuna plains of India. Acta Agriculture Serbia, 16.97-122.
Ravikumar, S., Kathiresan, K., Ignatiammal, S.T.M., Selvam, M.B. and Shanty, S. (2004). Nitrogen-fixing azotobacters from mangrove habitat and their utility as marine biofertilizers. Journal of Experimental Marine Biology and Ecology 312: 5–17.
Sanoria, C.L. and Sundara Rao, W.V.B. (1975). Effect of seed bacterization with Azotobacter chroococcum on sorghum and wheat. Indian J. Agric. Sci. 45: 224-226.
Stella, M. and Suhaimi, M. (2010). Selection of suitable growth medium for free-living diazotrophs isolated from compost. J. Trop. Agric. and Fd. Sc. 38(2): 211–219.
Tejera, N., Luch, C., Martinez-Toledo, M.V., Gonzalez-Lopez, J. (2005). Isolation and characterization of Azotobacter and Azospirillumstrains fromsugarcane rhizosphere. J. Plant and Soil: 223–232.
Tippannavar, C.M. and Reddy, T.K.R. (1987). Population dynamics of Azotobacter in different soil types, their nitrogen fixing capacities and effect of Azotobacter isolates on wheat seed germination. J. Farm. Sys. 3(3-4): 67-71.
Torres-Rubio, M.G., Valencia-Plata, S.A., Bernal-Castillo J. and Martienez-Nieto, P. (2000). Isolation of Enterobacteria, Azotobacter sp. and Pseudomonas sp., Producers of Indole-3-Acetic Acid and Siderophores from Colombian Rice Rhizosphere. R.L. De Microbiologiea, 42: 171-176.
Voets, J.P. and Dedeken, M. (1966). A physiological approach to the classification of the genus Azotobacter (c.f.) The biological fixation of atmospheric nitrogen by free living bacteria. In : “Soil Biology: Review of Research”. Nat. Resour. Res. UNESCO, 9: 65-125.
Winogradsky, S.N. (1949). Microbiologie du soil problems et methods (e.f.). The Azotobacteraceae. In: Bacterial Review. 18: 199.
Citation Format
How to Cite
Upadhyay, S., Kumar, N., Singh, V. K., & Singh, A. (2015). Isolation, characterization and morphological study of Azotobacter isolates. Journal of Applied and Natural Science, 7(2), 984-990. https://doi.org/10.31018/jans.v7i2.718
More Citation Formats:
Section
Research Articles