Figure 2.

Expression of abpA gene in Streptococcus gordonii by quantitative reverse transcription–polymerase chain reaction. Bacteria were cultured to mid-log phase and pelleted. To the pellet one of the following was added and the mixture was incubated for 40 min in a candle jar at 37°C: fresh defined medium (DM); DM supplemented with 1% glucose (G); 1% starch and 0.5 mg ml⁻¹ amylase (SA); 1% maltose (M2); 1% maltotriose (M3); 1% maltotetraose (M4); 1% maltopentaose (M5); 1% maltohexaose (M6); 1% maltoheptaose (M7); 1% maltoheptaose with 0.5 mg ml⁻¹ amylase (M7A); 1% starch (S); 0.5 mg ml⁻¹ amylase (A). The gyrA gene was used as endogenous control. Incubation in minimal fresh DM was used as the calibrator; log2 of relative quantity (RQ) is presented.