Lysozyme is a naturally occurring alkaline hydrolase renowned for its bacteriolytic activity. Its core function is to catalyze the hydrolysis of β-1,4 glycosidic bonds in bacterial cell wall peptidoglycan, disrupting the cell wall structure and leading to bacterial lysis.
Abundantly present in fresh egg whites, lysozyme boasts advantages such as stable properties, high safety, and easy extraction-hence it is typically derived from egg whites. Notably, egg white lysozyme is the only natural bacteriostatic agent recognized as GRAS by the U.S. FDA, with widespread applications in the food, pharmaceutical, daily chemical, and feed industries.
Mechanism
The core lysis mechanism involves the specific hydrolysis of key glycosidic bonds in bacterial cell wall peptidoglycan, decomposing the insoluble polysaccharides of the cell wall into soluble glycopeptides. This disrupts the integrity of the cell wall, resulting in bacterial death.
Applications in Food Industry
Lysozyme is widely used as a biological bacteriostatic agent in foods such as meat and meat products, dairy products, fermented beverages, and fruits and vegetables:
1. Meat and Meat Products: Lysozyme inhibits Listeria monocytogenes in pork, beef, and pork sausages, facilitating the production and circulation of meat products. By specifically disrupting the cell wall structure of Gram-positive bacteria, it suppresses bacterial growth and reproduction during cold storage or room-temperature preservation, effectively delaying meat spoilage and significantly extending product shelf life.
2. Dairy Products: In the industrial production of cheese and other dairy products, lysozyme inhibits the growth of Clostridium tyrobutyricum and Clostridium spores, respectively. Adding lysozyme or its hydrolysates to yogurt not only improves product quality but also inhibits the growth of molds, yeasts, and other microorganisms. Lysozyme ensures quality stability during dairy production and substantially prolongs shelf life.
3. Fruit and Vegetable Preservation: Lysozyme can be used for preserving fruits and vegetables by forming a biofilm coating on their surfaces to inhibit the growth of spoilage microorganisms. This biofilm prevents microbial invasion during storage, safeguarding the quality of fruits and vegetables throughout the preservation period.
Applications in Pharmaceutical Industry
In pharmaceuticals, lysozyme is primarily used as a bacteriostatic and anti-inflammatory agent. To enhance its efficacy, it is often combined with other ingredients and formulated into lozenges, drops, gels, ointments, and other dosage forms.
Applications in Daily Chemical Care
Lysozyme is widely incorporated into toothpaste, mouthwash, hand sanitizers, and other personal care products. Its mild bacteriostatic activity effectively cleanses harmful bacteria from oral and skin surfaces, preventing tooth decay and skin infections.
Applications in the Feed Industry
Lysozyme is mainly used as an antibiotic alternative in animal feed to enhance animals' innate immunity. By regulating the balance of intestinal flora in animals, it improves feed conversion rates and the quality of livestock products, aligning with the industry trend of antibiotic-free breeding.