Assimilation kinetics of [1, 2-¹³C]-acetate during mixotrophy.

<p>(A) Assimilation kinetics of acetate by <i>C. reinhardtii</i>, as studied by recording proton decoupled 1D [¹³C]-NMR spectra, during mixotrophic growth at different time points following the addition of [1, 2-¹³C]-acetate to the TP growth medium. The spectra from the same experiment are stacked for representation. (The signs * and ** represent methyl and carboxyl peaks respectively of [1, 2-¹³C]-acetic acid, and the signs⁺and⁺⁺represent bicarbonate and CO₂^aqpeaks respectively). (B) Quantitative analyses of [¹³C]-methyl peak intensity of acetate and metabolites (bicarbonate) at different time intervals during mixotrophy. Peak intensities (area under the peaks) were normalized with respect to the 0 hr data for acetate. Values are mean of three independent experiments ± SD. (C) Proton decoupled 1D [¹³C]-NMR spectra recorded on a 700 MHz NMR spectrometer equipped with a TXO probe, optimized for direct [¹³C] detection, at 298 K of cells grown in mixotrophy for 24 hrs in TP growth medium containing [1, 2-¹³C]-acetate. Starch and lipid signals are assigned by comparison with corresponding standards (see legend <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106457#pone.0106457.s005" target="_blank">Fig. S5</a>).