Purification of DNase Enzyme from Staphylococcus aureus Isolated from Various Clinical Sources

This study designed to isolate and purify (DNase) from Staphylococcus aureus that isolated from several clinical source collected at Al-Shaheed Al-Sader Hospital within the period extended from December 2023 to June 2024, it was 200 isolates. The isolates were screened for DNase production by using qualitative and quantitative assay, with 94% were DNase producers. The highest DNase production was detected in isolate S129, which was subjected to purification by precipitation with ammonium sulfate, ion exchange chromatography (IEC), and gel filtration chromatography. DNase activity was optimized at a saturation range of (75-85)% ammonium sulfate, and the maximum purity was achieved by ion exchange chromatography with (0.3 M NaCl), 121 U/mg specific activity of and a overall yield 21.1%. The results confirm the widespread production of DNase in S. aureus and demonstrate the effectiveness of the applied purification methods, providing valuable insights for further research on DNase as a virulence factor.