Spectrally decomposed dark-to-light transitions in a PSI-deficient mutant of Synechocystis sp. PCC 6803

Alonso M. Acuña, Pascal van Alphen, Filipe Branco dos Santos, Rienk van Grondelle, Klaas J. Hellingwerf, Ivo H.M. van Stokkum*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

127 Downloads (Pure)

Abstract

Cyanobacterial thylakoid membranes are known to host photosynthetic and respiratory complexes. This hampers a straight forward interpretation of the highly dynamic fluorescence originating from photosynthetic units. The present study focuses on dark-to-light transitions in whole cells of a PSI-deficient mutant of the cyanobacterium Synechocystis sp. PCC 6803. The time-dependent cellular fluorescence spectrum has been measured, while having previously exposed the cells to different conditions that affect respiratory activity. The analysis method used allows the detected signal to be decomposed in a few components that are then assigned to functional emitting species. Additionally, we have worked out a minimal mathematical model consisting of sensible postulated species to interpret the recorded data. We conclude that the following two functional complexes play a major role: a phycobilisome antenna complex coupled to a PSII dimer with either two or no closed reaction centers. Crucially, we present evidence for an additional species capable of strongly quenching fluorescence, whose formation requires the presence of oxygen.

Original languageEnglish
Pages (from-to)57-68
Number of pages12
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1859
Issue number2
Early online date11 Nov 2017
DOIs
Publication statusPublished - Feb 2018

Keywords

  • Cyanobacteria
  • Singular Value Decomposition
  • Spectrally-resolved fluorometry
  • Time-resolved spectroscopy

Fingerprint Dive into the research topics of 'Spectrally decomposed dark-to-light transitions in a PSI-deficient mutant of Synechocystis sp. PCC 6803'. Together they form a unique fingerprint.

Cite this