微生物与生化技术杂志

抽象的

Purification and Characterization of Superoxide Dismutase Isolated From Sewage Isolated E. coli

Petkar Medha B, Dr. Pillai Meena M, Kulkarni Amarja A, Bondre Sushma H and Dr KRSS Rao

Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, has therapeutic importance. It was purified from sewage isolated E. coli and characterized. Eukaryotic cells also produce SOD but culturing and maintenance of eukaryotic cells for production of SOD is costly as well as difficult. Using prokaryotic cells i.e. bacteria, production cost can be reduced. A rich bacterial source was identified. Bacterial membrane was ruptured in the presence of lysozyme and glass bead. Following ammonium sulphate precipitation, SOD-containing solution was applied to DEAE-cellulose and then Sephadex G- 75 gel columns. SOD was purified 63.91-fold with a specific activity of 3835U/ mg. The molecular weight was estimated to be 35.713 kDa by SDSPAGE gel. Maximum SOD activity was observed between pH 7.0 to 7.5 at temperature range 37–50ºC. This enzyme has fair thermal stability. The enzyme was found to be stable in presence of 1% salt only. The activity found to be gradually reduced approximately 50% at higher concentrations. It was totally inactivated above 9% salt concentration.