An analysis of the distribution of key metabolic fluxes in Chlamydomonas reinhardtii cells under the conditions of a sulfur deficit

A stoichiometric model that combines the reactions of central metabolism and the electron transport processes of respiration and primary photosynthetic reactions in a plant cell is considered. The central metabolic reactions, including glycolysis, the Calvin cycle, and the Krebs cycle, are associated with electrontransport processes via the NAD(P)H redox equivalents. The model is defined by algebraic equations and includes rules that enable the description of the change in the direction of metabolism dependent on the availability of different carbon sources. Experimental data on the changes of the levels of individual cellular metabolites in the alga Chlamydomonas reinhardtii under the conditions of sulfur deprivation were used to verify the model. The model allowed the generalization of the existing concepts of the changes in the direction of metabolic fluxes under the conditions of sulfur starvation.