Journal of Applied Phycology

, Volume 8, Issue 4, pp 325–333

Microscopic green algae and cyanobacteria in high-frequency intermittent light

  • Ladislav Nedbal
  • Vladimír Tichý
  • Fusheng Xiong
  • Johan U. Grobbelaar

DOI: 10.1007/BF02178575

Cite this article as:
Nedbal, L., Tichý, V., Xiong, F. et al. J Appl Phycol (1996) 8: 325. doi:10.1007/BF02178575


The effects of fluctuations in the irradiance onScenedesmus quadricauda, Chlorella vulgaris andSynechococcus elongatus were studied in dilute cultures using arrays of red light emitting diodes. The growth rate and the rate of photoinhibition were compared using intermittent and equivalent continuous light regimes in small-size (30 ml) bioreactors. The CO2 dependent photosynthetic oxygen evolution rates in the intermittent and continuous light regimes were compared for different light/dark ratios and different mean irradiances. The kinetics of the electron transfer reactions were investigated using a double-modulation fluorometer. The rates of photosynthetic oxygen evolution normalized to equal mean irradiance were lower or equal in the intermittent light compared to the maximum rate found in the equivalent optimal continuous light regime. In contrast, the growth rates in the intermittent light can be higher than the growth rate in the equivalent continuous light. Photoinhibition is presented as an example of a physiological process affecting the growth rate that occurs at different rates in the intermittent and equivalent continuous lights. The difference in the dynamics of the redox state of the plastoquinone pool is proposed to be responsible for the low photoinhibition rates observed in the intermittent light.

Key words

algaecyanobacteriagrowth rateintermittent lightoxygen evolutionphotoinhibition



constant fluorescence measured with all QAoxidized


light emitting diodes


Photosystem II


primary quinone acceptor of the Photosystem II

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Ladislav Nedbal
    • 1
  • Vladimír Tichý
    • 1
  • Fusheng Xiong
    • 1
  • Johan U. Grobbelaar
    • 2
  1. 1.National Research Center for Photosynthesis and Global Climate ChangeInstitute of Microbiology AVČRTřebonCzech Republic
  2. 2.Department of Botany and Genetics, UOFSBloemfonteinSouth Africa