© 2013, 2020, 2025: Douglas B. Murray, Rainer Machné.
Dynamics of respiratory activity in continuous culture of the yeast strain IFO 0233 (Satroutdinov, Kuriyama, and Kobayashi 1992; Klevecz et al. 2004; Murray, Beckmann, and Kitano 2007; Machné and Murray 2012). The O\(_2\) concentration in the reactor is shown in the top row, CO\(_2\), O\(_2\) flux, H\(_2\)S concentrations, and metabolic heat production \(\Delta Q\) are plotted against each other in the second row. The third row shows phase diagrams of O\(_2\) and CO\(_2\) fluxes and Poincaré maps of amplitudes and periods of the dissolved O\(_2\) signal.
Click here for detailed methods. In short, Dougie ran a culture of the yeast strain IFO 0233 for 200 hours at first in batch until glucose ran out, then (red arrow ‘fresh media' at ca. 44 h) at as a continuous culture with a dilution rate \(\phi=0.089 \text{h}^{-1}\), calculated from the decrease of the mass of the medium reservoir bottle. Offgas concentrations of O\(_2\), CO\(_2\) and H\(_2\)S were recorded, and we calculated the cell production fluxes \(q\) in mol/h/g\(_\text{DCW}\). Since cells consume O\(_2\), this flux is displayed negative. The pH of the culture was controlled by addition of NaOH to compensate for the acidification by cell metabolism, and proton (H\(^+\)) production was calculated from the decrease of the mass of the NaOH bottle. Temperature was controlled by a water flow through the jacket of the reactor vessel and temperatures inside the reactor and in the jacket recorded. The heat produced by the cells and the reactor machinery can be calculted from the difference of these temperatures, and here we plot the difference of this heat to the heat produced before onset of the continuous culture mode, i.e., during a starvation phase.