Fig. 7
Transition from aerated to anaerobic cultures. O2-grown cells were transferred to anaerobic bottles with fresh RRNCO medium, and 40 mM fructose. Bicarbonate was added (0.0 mM, 3.0 mM, 6.0 mM, 12.0 mM) and the pH adjusted to 7.0 with HCl 0.1 N. A Growth curves of OD660 and B PM production. Only the cultures with bicarbonate were able to grow in the lapse of the experiment. PM production depended upon bicarbonate concentration. C Total protein measured with the Bradford method of cells in time-point cero (light blue or light red) and at the end of the experiment (dark blue or red). D PHBV accumulation and E 3HV %mol was the same for all the conditions as long as they had bicarbonate. F Production of CO2 and H2 was quantified, resulting in a net accumulation of both gases in the headspace of the bottles. 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