Figure 1.

(A) Detection of AI-2 activity during growth of S. epidermidis 1457 and S. epidermidis 1457ΔluxS. Every hour, cell-free supernatants were examined for the capacity to induce light production in V. harveyi BB170. Data were obtained from at least three independent experiments and normalized against light production in TSB or TSB/0.5% glucose. (B) Growth of S. epidermidis 1457 and S. epidermidis 1457ΔluxS in TSB with different concentration of glucose. Overnight cultures were 1:100 diluted in TSB without glucose or TSB supplemented with 0.5% glucose and the OD_{600 nm} during growth of the main cultures was determined. (C) AI-2 activity during incubation with S. epidermidis 1457ΔluxS and in media controls. AI-2 was added to cells of S. epidermidis 1457ΔluxS at exponential growth phase in TSB without glucose and TSB with 0.5% glucose. The same quantity of AI-2 was added to the cell-free culture as control. Afterwards, every hour 1 ml of cell-free supernatant was collected for the detection of AI-2 activity.