Fig. 3

Comparison of fluorometric intensity measurements of E. coli BL21 strains NisSTldhSTldh and NisSTldhT7, expressing mCherry-NisA cultured in terrific broth containing glucose (1% v/v) and induced with 0.15 mM IPTG and 0.5% glycerol (v/v). STldhSTldh: STldh promoter used for expression of mCherry-NisA and NisB; STldhT7: STldh used for expression of mCherry-NisA and T7 promoter for NisB. Means (SEM) from three independent (n = 3) cultures are shown. Different single-letter combinations indicate which groups have significance at different time points and should be interpreted as (a) vs (a) = no difference; (a) vs (b) = different and (b) vs (c) = different. Error bars show standard deviation. Statistical differences were determined by two-way ANOVA (P < 0.05, P < 0.01 and P < 0.001)