Expression analysis of Thermus thermophilus HB8 wild-type strain in response to high growth temperature

In order to observe the heat-shock response of extremely thermohilic bacterium T. thermophilus HB8 strain, we analyzed the altered expression profile of the total mRNA in T. thermophilus HB8 wild-type strain after the growth temperature was shifted from 70°C to 80°C for 30 min. Three wild-type strain of T. thermophilus HB8 were pre-cultured at 70°C for 16 hours in 3 mL of TT medium containing 0.8% polypeptone, 0.4% yeast extract, 0.2% NaCl, 0.4 mM CaCl2, and 0.4 mM MgCl2, which was adjusted to pH 7.2 with NaOH. The cells (0.5 mL) were inoculated into 250 mL of TT medium and then cultivated at 70°C for 6 hours. After the cells were collected from 50 ml culture medium, the remaining medium was cultured at 80°C for 30 min. The cells were collected, and then crude RNA was extracted from each lot of cells. The expression of each mRNA at each time point was analyzed on a GeneChip.