Isolation and Molecular Identification of Auxotrophic Mutants to Develop a Genetic Manipulation System for the Haloarchaeon Natrinema sp. J7-2

Figure 4

Expression of bgaH gene in J7-2-1 via the integrative plasmid pUC19-HM1752-bgaH. The plasmid pUC19-HM1752-bgaH containing bgaH was transformed into strain J7-2-1. In total, 200 transformants were picked out randomly and cultured. The activity of β-galactosidase in these 200 transformants was detected on four MGM plates (50 transformants on each plate) supplied with X-gal (detailed process is discussed in Materials and Methods). If the transformants had β-galactosidase activity, the color of the corresponding colony would turn blue. The results were recorded and pictures taken after the four plates were stored at 42°C for 7–15 days. P: positive control. N1: negative control Hfx. volcanii DS52. N2: negative control J7-2-1. N3: negative control J7-2-1 transformed with J7-2 genome. N4: negative control J7-2-1 transformed with KM1752 fragment.