Lysozyme monomer exhibits strong antibacterial activity against Gram-positive organisms. This phenomenon has found a practical application in the food processing industry, in medicine and pharmaceutical industry. The use of lysozyme in the food processing industry is connected primarily with its application as a natural preservative. The enzyme is widely used as a preservative for meat, fish and their products, for milk and dairy products, as well as for fruit and vegetables. The pharmaceutical industry uses this enzyme in the manufacture of adjuvant drugs for antibiotics and analgesics in viral and bacterial infections, in the treatment of leukemia and neoplastic diseases. Lysozyme is also used as a diagnostic agent, being an indicator of the occurrence and the progression of pathological changes in humans and animals. The range of the practical applications of lysozyme may be considerably extended as a result of its modification. The enzyme after modification exhibits a new specific activity in relation to Gram-negative bacteria, being a result of dimerization, with no loss of activity against Gram-positive bacteria, characteristic for the monomer, as it was indicated in studies by Ibrahim et al. [1991;1996], Lesnierowski et al. [2004] and Kijowski et al. [2006]. The dimeric form of lysozyme has been used in the treatment of bacterial and viral animal diseases. A drug produced on the basis of lysozyme dimer shows immunostimulating and immunocorrective activity.