Figure 3
Cytotoxicity, hemolytic and protease activities of the wild-type, ΔnorV mutant, and complemented CΔnorV strains grown under various conditions. Cytotoxicity was expressed as LDH release of RAW264.7 macrophages induced by culture supernatants collected from bacteria grown under aerobic (A) and anaerobic (B) conditions after exposure to various concentrations of SNP. The hemolytic activities of each strain grown under aerobic (C) and anaerobic (D) conditions after treating with various concentrations of SNP were expressed as the dilution-fold of the A. hydrophila culture filtrates that led to the lysis of 50% erythrocytes. The protease activities of A. hydrophila strains cultured in LB media containing various concentrations of SNP under aerobic (E) and anaerobic (F) conditions were measured at OD440 with azocasein as the substrate. Values are the means ± SD from three biological replicates. ***P < 0.001.