Журнал биоинженерии и биомедицинских наук

Extraction and Biochemical Characterization of a High Potential Iron- Sulfur Protein (Hipip) from Acidthiobacillus Species Isolated from Agbaja Iron Mines of Kogi State, Nigeria

Abstract

Ekpa E, Onwurah INE, Ezeanyika LUS and Iyayi A

A high potential iron-Sulphur protein (HiPIP) Iron Oxidase (E.C 1.9.3.1) was isolated from Acidithiobacillus species obtained from Ironstones of Agbaja Mines of Kogi State, Nigeria. The aim was to study the biochemical characteristics of the enzyme so as to find out its catalytic contribution to the rate of bioleaching of the studied organism. A simple partial purification profile consisting of cell homogenization, ammonium sulphate precipitation, Ion-exchange using Carboxyl methyl cellulose, and sephadex G-200 chromatography were used. The biochemical and kinetic properties of the enzyme were thereafter studied. The Iron oxidase had its highest specific activity of 14.70 μmole/ml/mg of protein and yield of 89% with a purification fold of 1.43 after size exclusion chromatography. Optimum temperature and pH were found to be 50°C and 6.0 with Km and Vmax of 0.03mM and 12 mMole/min respectively. Inhibition studies conducted shows that tween 20 and SDS had the maximum rates. Other characteristics of the enzyme show that it might be a novel member of HiPIP coming from the isolated Acidithiobacillus of Agbaja Iron ore Mines.