Fig. 7. Escapin can be bacteriostatic or bactericidal. (A) Inhibition of growth. E. coli cells were incubated in LB medium at 37°C with 10 µg ml^-1 escapin (Esc) or without escapin (Control: buffer added instead), and with or without 0.4-1.6 mg catalase (Cat). Absorbance at 600 nm was measured at the indicated incubation times to determine cell density. This experiment was repeated twice more with similar effects. (B) Bactericidal effect. E. coli cells were grown in LB medium containing 3 x10⁸ cells ml^-1, then incubated in escapin (10 µg ml^-1) in LB medium at 37°C (closed squares) or 0°C (open squares). Values are means ± S.E.M., N=3.