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

Abstract

Lysozyme from saliva of Bali cattle (Bos sondaicus) was successfully isolated through an aqueous mixture system of polyethylene glycol (PEG 4000) and salt (Na₂SO₄). About 100 μg/ml lysozyme of 14.2 kDa, determined through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), per 4800 μg/ml saliva was obtained. Based on turbidity assay of Staphylococcus aureus, it was revealed that inhibition activities of 40 μg/ml isolated lysozyme were comparable to 800 μg/ml of a commercial hen egg white lysozyme.

Key words: Lysozyme, Bali cattle, Bos sondaicus, PEG, aqueous mixture system.