FIG 2.

Oxygen deprivation modulates V. cholerae AI production. (A) 80%, (B) 25%, or (C) 30% cell-free culture fluids prepared from WT V. cholerae grown in the presence or absence of O₂ were provided to V. cholerae reporter strains that produce bioluminescence in response to exogenous (A) CAI-1, (B) AI-2, or (C) DPO. Data represent the average values from biological replicates (n = 3), and error bars represent SD. Statistical significance was calculated using a two-tailed Student t test. Asterisks are as follows: * denotes P < 0.05, *** denotes P < 0.001, and **** denotes P < 0.0001. LOD, limit of detection; AU, arbitrary units.