Journal of Pure and Applied MicrobiologyVol. 1 No. 2

Hydrogen Peroxide Mediated Oxidative Stress Endurance in Azorhizobium Caulinodans -ORS-571

M. Melvin Joe* and P.K. Sivakumaar

Department of Microbiology, Faculty of Agriculture, Annamalai University, Annamalainagar, India.

Received on 18 September 2007 and accepted on 21 October 2007



The process of symbiotic nitrogen fixation results in generation of reactive oxygen species such as superoxide anion (O2-) and hydrogen peroxide (H2O2). The response of Azorhizobium caulinodans to these toxic oxygen species is an important factor in nodulation and nitrogen fixation. It has been found that pretreatment of A.caulinodans with low, non-lethal levels of a selective oxidant viz., H2O2 (200ÁM) imparts resistance to oxidative mortality. The catalase activity was also found to be higher in H2O2 pre-treated cells than untreated controls.

Keywords : Azorhizobium caulinodans, Catalase, Hydrogen peroxide.