FIG 1.

Flavobacterium psychrophilum (CSF 259-93) was cultured in the presence of supernatant from Enterobacter (C6-6) or Escherichia coli (K-12). Unfiltered supernatant and the ≤3-kDa fraction from both species inhibited growth of F. psychrophilum, whereas treatment with the higher-mass fraction (>3 kDa) was indistinguishable from treatment with spent medium from F. psychrophilum (Control). Bars represent means plus standard errors of the means (SEM). Asterisks represent differences from the control (P < 0.05; one-way ANOVA and Tukey's multiple-comparison test).