[Characteristics of the effect of egg lysozyme on micrococci and staphylococci]

The nature of the optical density of suspensions of Staph. aureus and M. luteus cells at various concentrations of chicken egg albumin lysozyme and two products of its chemical transformation was studied comparatively. The experiments were performed in 1/15 M Na-phosphate buffer at pH 6.2 and a temperature of 20-22 degrees C. It was shown that the decrease in the optical density of the suspensions observed at relatively low concentrations of lysozyme, i.e. 0.032-0.064 mg/ml, was due to lysis of both microbial species. The increase in the optical density of the suspensions at higher (0.5-2.0 mg/ml) concentrations of lysozyme was connected with formation of insoluble aggregates of an electrostatic character. Lysozyme in such aggregates is the positively charged component and the microbial cell material is the negatively charged component. When M. luteus strains are sensitive to lysozyme, the aggregates are formed from the cell fragments or lysis acid products. When Staph, aureus strains have higher resistance levels, the aggregates are formed from both the lysis products and the intact live cells which is of special interest.