Fig. 4

The effect of pH and temperature on the peptidase M15A lytic activity against E. coli XL1-Blue peptidoglycan. The optical density at 600 nm of cell suspensions was used to observe the effects of pH a and temperature b on the peptidase M15A lytic activity against E. coli XL1-Blue peptidoglycan. The grey bars show negative controls without enzyme and black bars indicate the reaction with enzyme. p value <0.05 (*) and 0.01 (**) indicate the significance. Each column represents the mean of triplicate experiments and error bars indicate SD