溶菌酶（lysozyme）又称胞壁质酶（muramidase）或N-乙酰胞壁质聚糖水解酶（N-acetylmuramide glycanohydrlase），是一种能水解致病菌中黏多糖的酶。在自然界中，溶菌酶普遍存在于鸟类、家禽的蛋清和哺乳动物的眼泪、唾液、血液、鼻涕、尿液、乳汁和组织细胞中(如肝、肾、淋巴组织、肠道等) ，从植物中也能分离出溶菌酶（如木瓜、芜青、大麦、无花果和卷心菜、萝卜等）。

Lysozyme, also known as muramicase or N-acetylmuramicide glycolase, is an enzyme that can hydrolyze mucopolysaccharides in pathogenic bacteria. In nature, lysozyme is commonly found in the egg whites of birds and poultry, as well as in the tears, saliva, blood, nasal mucus, urine, milk, and tissue cells of mammals (such as liver, kidney, lymphoid tissue, intestine, etc.). Lysozymes can also be isolated from plants (such as papaya, turnip, barley, figs, cabbage, radish, etc.).