The evaluation of bacteriocin cytotoxicity is a critical first step in guaranteeing its safe use in food and therapeutic applications. In this study, the bacteriocins nisin, pediocin, and colicin ([Col] E1, E3, E6, E7, and K) were evaluated for cytotoxicity against cultured mammalian cells. Cellular membrane potential (delta psi) changes of bacteriocin-treated cells were used as an index of cytotoxicity. Simian virus 40-transfected human colon (SV40-HC) cells and African green monkey kidney epithelial cells (Vero) cells were cultured (35°C, 10% CO2, humidified air) as monolayers on tissue culture plates. Log phase cells (~104 cells/mL) were treated with partially purified, individual bacteriocin preparations at 170, 350, and 700 activity units (AU)/mL…