title: Circadian rhythms in the cell cycle and biomass composition of Neochloris oleoabundans under nitrogen limitation.
abstract: The circadian clock schedules processes in microalgae cells at suitable times in the day/night cycle. To gain knowledge about these biological time schedules, Neochloris oleoabundans was grown under constant light conditions and nitrogen limitation. Under these constant conditions, the only variable was the circadian clock. The results were compared to previous work done under nitrogen-replete conditions, in order to determine the effect of N-limitation on circadian rhythms in the cell cycle and biomass composition of N. oleoabundans. The circadian clock was not affected by nitrogen-limitation, and cell division was timed in the natural night, despite of constant light conditions. However, because of nitrogen-limitation, not the entire population was able to divide every day. Two subpopulations were observed, which divided alternately every other day. This caused oscillations in biomass yield and composition. Starch and total fatty acids (TFA) were accumulated during the day. Also, fatty acid composition changed during the cell cycle. Neutral lipids were built up during the day, especially in cells that were arrested in their cell cycle (G2 and G3). These findings give insight in the influence of circadian rhythms on the cell cycle and biomass composition.
authors: Bioprocess Engineering, AlgaePARC, Wageningen University, www.algaePARC.com, PO Box 8129, 6700 EV Wageningen, The Netherlands; Wetsus-Center of Excellence for Sustainable Water Technology, PO Box 1113, 8900 CC Leeuwarden, The Netherlands. Electronic address: lenneke.dewinter@wur.nl.
authors: Lenneke
authors: L
authors: de Winter
authors: Bioprocess Engineering, AlgaePARC, Wageningen University, www.algaePARC.com, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors: Lutz W
authors: LW
authors: Schepers
authors: Bioprocess Engineering, AlgaePARC, Wageningen University, www.algaePARC.com, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors: Maria
authors: M
authors: Cuaresma
authors: Wageningen UR Food and Biobased Research, AlgaePARC, PO Box 17, 6700 AA Wageningen, The Netherlands.
authors: Maria J
authors: MJ
authors: Barbosa
authors: Bioprocess Engineering, AlgaePARC, Wageningen University, www.algaePARC.com, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors: Dirk E
authors: DE
authors: Martens
authors: Bioprocess Engineering, AlgaePARC, Wageningen University, www.algaePARC.com, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors: René H
authors: RH
authors: Wijffels
mesh_terms: D018533:Biomass; D002453:Cell Cycle / Q000502:physiology*; D000460:Chlorophyta / Q000378:metabolism* / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D058086:Microalgae / Q000378:metabolism* / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D009584:Nitrogen
keywords: Biomass composition; Cell cycle; Circadian rhythms; Microalgae; Nitrogen limitation