Activity of bacteriolytic enzymes adsorbed to clays

Myxococcus virescens is able to produce extracellular bacteriolytic enzymes that are rapidly adsorbed on montmorillonite. These adsorbed enzymes are active and can be assayed by measuring the release of UV-absorbing materials in mixtures containingMicrococcus luteus cells. The activity of the clay-adsorbed enzymes is, however, considerably lower than that of the unadsorbed enzymes. Both unadsorbed and adsorbed enzymes have their maximum activity at approximately the same pH. At lower clay-enzyme concentrations, the activity is proportional to the concentration. If, however, increasing amounts of clay are added to a fixed volume of clay-enzyme suspension, the activity remains almost unchanged until a definite limit is reached, then the activity decreases rapidly. This limit was dependent only on the ratio of the amounts of enzyme and clay and not on the absolute concentration of the enzyme. The montmorillonite-adsorbed bacteriolytic enzymes fromM. virescens were not active against gram-negative bacteria, and no activity against purified cell walls fromM. luteus could be measured. Montmorillonite-adsorbed egg white lysozyme was not active onM. luteus cells.