Time-course of mRNA expression in wild-type Thermus thermophilus HB8 grown on rich medium_long (labeling:Affymetrix)

In order to observe the growth phase-dependent expression profile of each mRNA of wild-type Thermus thermophilus HB8 strain grown in a rich medium at 70°C, we cultured the strain in a medium, and then the expression of total mRNA at the time points corresponding to logarithmic growth phase and early to late stationary growth phases was analyzed by using DNA microarray (GeneChip). Wild-type T. thermophilus HB8 strains were pre-cultured at 70°C for 16 h 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 (2 ml) were inoculated into 1 liter of the same medium and then cultivated at 70°C. Cells were collected after 180, 360, 540, 680, 880, 1000, 1120, and 1240 min, and then crude RNA was extracted. The expression of each mRNA at each time point was analyzed on a GeneChip.