Isolation and partial purification of lysozyme from saliva of Bali cattle (Bos sondaicus) using an aqueous mixture of polyethylene glycol (PEG) with sodium sulfate

Lysozyme from saliva of Bali cattle (Bos sondaicus) was successfully isolated through an aqueous mixture system of polyethylene glycol (PEG 4000) and salt (Na sub(2)SO sub(4)). About 100 mu g/ml lysozyme of 14.2 kDa, determined through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), per 4800 mu g/ml saliva was obtained. Based on turbidity assay of Staphylococcus aureus, it was revealed that inhibition activities of 40 mu g/ml isolated lysozyme were comparable to 800 mu g/ml of a commercial hen egg white lysozyme.