Growth rate changes in the evolution for thermal adaptation.

<p>The duplicated Line1 and Line2 from the final population at generation 7580 were passaged daily. The daily exponential growth rates at various temperatures were calculated based on the absorbance at 600 nm as described in the Materials and Methods section. a) Each color indicates the growth rates of the bacterial cells at 44.8°C (black), 45.0°C (pink), 45.2°C (blue), 45.4°C (orange), 45.6°C (green), 45.8°C (purple), and 46.0°C (red). The cell populations that were finally acquired at 46.0°C were subjected to genome sequencing analysis. b) The populations at generation 7580 (white) and the final populations of Line1 (gray) and Line2 (dark gray) were cultured to observe the growth rates at 20.0°C, 37.0°C, 45.0°C, 46.0°C, 46.5°C and 47.0°C. The average and standard errors were obtained by repeated cultures (n = 5–6).