Comparative expression analysis between PfmR (TTHB023) deletion mutant and wild-type of Thermus thermophilus HB8

We observed the expression profile of the total mRNA of PfmR (TTHB023) deletion mutant of Thermus thermophilus HB8 strain grown in a rich (TT) medium at 70°C compared with that of wild type. Seven wild-type and three mutant T. thermophilus HB8 strains were each pre-cultured at 70°C for 16 h in 4 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 were inoculated into 1 liter of the same medium and then cultivated at 70°C. Cells were collected after 360 min, and then crude RNA was extracted. In order to compare mRNA expression in the PfmR deletion mutant with that of wild type, the expression of each mRNA was analyzed on a GeneChip.