Fig. 5

Fluorometric measurements of strain NisSTldhT7 expressing mCherry-NisA under various culturing and induction conditions. Cultures were grown in terrific broth supplemented without (A) and with (B) glucose (1% v/v) for 24 h. Culturing and induction conditions included: (−IPTG; −GlyM; −GlyIn) no induction; (−IPTG; +GlyM; −GlyIn) no IPTG induction with glycerol (0.5% v/v) added to pre-growth media; (−IPTG; −GlyM; +GlyIn) no IPTG induction but induced with glycerol (0.5% v/v); (+IPTG; +GlyM; −GlyIn) induced with 0.15 mM IPTG and glycerol added to pre-growth media; (+IPTG; −GlyM; +GlyIn) induced with 0.15 mM IPTG and glycerol; (+IPTG; −GlyM; −GlyIn) induced with 0.15 mM IPTG. Fluorescence intensity was measured in relative fluorescence units (RFU Log₁₀). Means (SEM) from three independent (n = 3) cultures are shown with standard deviations indicated by error bars. Different single or double-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; (b) vs (c) = different and (ab) vs (bc) = different. Statistical differences were determined by two-way ANOVA (P < 0.05, P < 0.01, and P < 0.001). IPTG Thio-B-d-galactopyranoside, GlyM glycerol presence in pre-growth media, GlyIn glycerol used as inducer agent; +: added and −: not added