Fig. 6
Physiological characterization of R. rubrum in conditions O2, C2 and AL. A Nile-red stained cells under the optical/fluorescent microscope. Only condition C2 lead to observable PHBV granules. Pictures were taken at the moment of maximal PHBV accumulation. B RT-qPCR of phaC2 (PHA synthase) and cbbM (RuBisCO) in the exponential phase of growth (in the case of C2-grown cells, after they have started PM production (3 days). The transcriptional levels of phaC1 and phaC3 were undetectable (CT > 38). Fold change respect to the condition AL is represented. Statistical analysis was performed using one-way ANOVA followed by Dunnett’s comparison test. A significant effect was indicated by * (P < 0.05). C Net gas production at the stationary phase (10 days) of C2- and AL-grown cultures. The concentration of the gas was calculated as the total amount (mmol) of gas produced divided by the culture volume, to make it comparable to the other metabolites measured and the carbon source. D Total protein content measured by Bradford method. The percentage is referred to the residual biomass (Xr), i.e. without PHBV