Dynamics of the physiology, metabolome and proteins during the circadian cycle of Synechocystis sp. PCC 6803 under culturing conditions relevant for mass culturing

ABSTRACT: Here, we present the results of a study of the model cyanobacterium Synechocystis sp. PCC 6803, cultured in a lab-scale photobioreactor simulating physiological conditions present during large-scale culturing. The culture is flushed with N2 and CO2 without additional O2. This leads to an anoxic environment during the dark period. A circadian illumination regime of 12 h light/12 h dark is applied. We show that formation of biomass strictly follows the availability of light. The storage compound glycogen reached a maximum level of ~40 % of the cells gram dry weight already before the end of the light period. The subsequent consumption of glycogen during the dark period essentially only started in the last quarter of the dark period, which suggests anticipatory effects, possibly governed by the circadian clock, in order to prepare the cellular machinery for efficient energy usage. Most intracellular metabolite levels, as determined by Nuclear Magnetic Resonance analysis, from samples close to the transition points of light, change only mildly. Nevertheless, a distinct metabolic profile is evident from the cells sampled at different time points. Likewise, protein analysis by mass spectrometry shows moderate dynamics for the majority of the identified proteins. Both analyses suggest that in order to change the flux through a metabolic network the relative amounts of the metabolites and proteins do not need to change drastically, at least for the time points close to the change of the light regime.

INSTRUMENT(S): Synapt G2 MS

ORGANISM(S): Synechocystis Sp. Pcc 6803

SUBMITTER: Gertjan Kramer  

LAB HEAD: J.M.F.G. Aerts

PROVIDER: PXD001619 | Pride | 2016-09-27

REPOSITORIES: Pride