Fig. 2.
Relative fluorescence levels of screened promoters and stability of modified pCA2.4 strains. a Optical density measurements at OD730nm of growth of different YFP-expressing strains over 72 h. Chromosomally integrated (psbA2 locus) YFP strains UL006 (Ptrc-YFP), UL007 (Ptrc-YFP-E*) and UL008 (PpsbA2-YFP) grow similarly to WT. b Measurement of UL006, UL007 and UL008 YFP fluorescence levels after 72 h. The highest YFP fluorescence level detected was in UL006. Note 2 mM of the inducer theophylline was utilised to induce expression of the Ptrc riboswitch in UL007. c UL018 and UL006 strain stability after 80 days culturing. Lane 1 marker, lane 2 wild-type, lane 3 UL006 minus kanamycin, lane 4 UL006 plus kanamycin, lane 5 wild-type, lane 6 UL018 minus kanamycin, lane 7 UL018 plus kanamycin. The lower band indicates the presence of WT; higher band indicates construct integration. No evidence of the WT band in transconjugant strains was observed