Abstract
Hen egg white lysozyme was more effective than mutanolysin in killing lactic acid bacteria. The lysozyme-reated cell suspension had relatively high levels of turbidity but a low viability. On the other hand, the mutanolysin-reated cell suspension showed rather low levels of turbidity but a high cell survival number. Observations using a scanning electron microscope also showed differences in the appearances of the cells damaged by the treatment with each enzyme. The modes of action of the lysozyme and mutanolysin against the cell wall of lactic acid bacteria appeared to be quite different from each other though these enzymes are both a kind of peptidoglycan N-acetylmuramoylhydrolase. From these facts, it was found that for the killing of lactic acid bacteria, lysozyme is more effective than mutanolysin and the simultaneous use of both enzymes is much more effective than the use of a single type of enzyme.
