Development of a new host-vector system for colour selection of cloned DNA inserts using a newly designed β-galactosidase gene containing multiple cloning sites in Thermus thermophilus HB27.

We constructed a new Thermus thermophilus cloning vector which enables the colour selection of cloned DNA inserts in the T. thermophilus HB27 host strain (β-gal-) on growth plates containing 3,4-cyclohexenoesculetin β-D-galactopyranoside (S-gal) in the medium. This vector harbors a modified β-galactosidase gene (TTP0042 of T. thermophilus HB27) with 12 unique restriction enzyme sites (Acc65I, AvrII, BlpI, BssHII, EcoRI, EcoRV, HindIII, NruI, SalI, SpeI, SphI and XbaI) as multiple cloning sites under the control of the T. thermophilus slpA promoter. This host-vector system facilitates cloning procedures in T. thermophilus HB27.