Isolation production purification and characterization of thermostable bacterial superoxide dismutase

Abstract

newlineviii newlineABSTRACT newlineThe present study was conducted with the aim of isolating superoxide dismutase producing thermophilic bacteria from water samples of different hot water springs of Himachal Pradesh. One isolate from Manikaran named as M560 exhibited maximum superoxide dismutase activity out of seventy isolates. This isolate was identified, based on morphological and biochemical characteristics and also by molecular characterization. 16S rRNA sequencing results showed that the isolate was Anoxybacillus gonensis. In order to enhance the activity of SOD (superoxide dismutase), response surface methodology (RSM) based on central composite design was used. newlineFurther superoxide dismutase of Anoxybacillus gonensis was purified to homogeneity. A purification factor of 33.1-fold was achieved, with the purified enzyme exhibiting specific activity of 5758.4 U/mg protein. The molecular weight of superoxide dismutase was calculated as 31 kDa by SDS-PAGE. The native-PAGE analysis showed that superoxide dismutase of Anoxybacillus gonensis exists as homodimer (62 kDa). Inhibition studies on purified superoxide dismutase showed that it was Cu/Zn type superoxide dismutase. This is the first report ever showing purification of superoxide dismutase from Anoxybacillus gonensis. newlineA gene encoding superoxide dismutase of approximately 491 bp was also amplified using genomic DNA of Anoxybacillus gonensis KA 55. In silico docking studies have shown which amino acid residues were involved in forming hydrogen bond and hydrophobic interactions with various inhibitors. Keywords: Superoxide dismutase, Anoxybacillus gonensis, 16S rRNA, Response Surface Methodology, In silico, Hydrophobic, Inhibitors