FIG. 4.

Cytotoxic effects of bacterial supernatant (S. chromogenes 690LR) on Y-1 cells. B-broth and bacterial cultural supernatants were diluted in Ham F-12 medium, loaded onto a Y-1 cell monolayer, and incubated for 20 h at 37°C in 95% air and 5% CO₂. (A) B-broth at a 1:2.5 dilution in Ham F-12 medium caused no cytopathic effects on cultured Y-1 cells. (B) Bacterial supernatants at 1:2.5 and 1:5 dilutions in Ham F-12 medium caused rounding of Y-1 cells.