Purification and characterization of Hemolysin produced by local isolates of Vibrio cholera

Abstract

The Hemolysin was Extracted from Vibrio cholera cultured on Brain Heart infusion by cold centrifugation 5000 r/min for 15 min at 4°C, and purified by several steps, including precipitation with 75% saturation ammonium sulphate, ion exchange chromatography using DEAE-cellulose and gel filtration on Sephadex G-100 column. The obtained purification foldand recovery were 24.26 unit /ml and 32.47% respectively. The molecular weight of the enzyme is about 19490 Dalton as determined by gel filtration. The optimum pH for activity and stability was 6 and 6-8 respectively. The enzyme retained its original activity when incubated at 20-45oC for 15 min, the activity of the enzyme decreased after enzyme incubation at 45oC. The maximum enzyme activity observed at 30oC.