mRNA expression in wild-type of Thermus thermophilus HB8 strain grown on a rich (TT) medium at 45˚C and 70˚C

We observed the expression profile of the total mRNA of wild-type of Thermus thermophilus HB8 strain grown in a rich (TT) medium at 45˚C compared with that of 70˚C. Keywords: Growth temperature Wild-type T. thermophilus HB8 strain was pre-cultured at 70˚C for 5 h in 5 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 7.5 with NaOH. The cells (5 ml) were inoculated into 0.30 liter of the same medium and then cultivated at 70˚C. At the Abs600 =0.8 (0min), this culture was divided into two flasks. Then, equal volume of cold medium (4˚C) was added and the temperature were shifted down to 45˚C. Hot medium (70˚C) was added to the other flask. Cells were collected at 0.5 min and 10 min after temperature shift in the equal volume of 100% ice-cold ethanol, and then crude RNA was extracted. In order to compare mRNA expression in the wild-type strain between 45˚C and 70˚C, the expression of each mRNA at each time point was analyzed on a GeneChip as described for each sample in this website.