Cited by 76Photosynthetic Processes and MechanismsAlgal biology and biofuel productionLipid metabolism and biosynthesis

Cyanobacterial Alkanes Modulate Photosynthetic Cyclic Electron Flow to Assist Growth under Cold Stress

Open access
Berla, Bertram M., Saha, Rajib, Maranas, Costas D., Pakrasi, Himadri B.·2015·Scientific Reports

Abstract

All cyanobacterial membranes contain diesel-range C15-C19 hydrocarbons at concentrations similar to chlorophyll. Recently, two universal but mutually exclusive hydrocarbon production pathways in cyanobacteria were discovered. We engineered a mutant of Synechocystis sp. PCC 6803 that produces no alkanes, which grew poorly at low temperatures. We analyzed this defect by assessing the redox kinetics of PSI. The mutant exhibited enhanced cyclic electron flow (CEF), especially at low temperature. CEF raises the ATP:NADPH ratio from photosynthesis and balances reductant requirements of biosynthesis with maintaining the redox poise of the electron transport chain. We conducted in silico flux balance analysis and showed that growth rate reaches a distinct maximum for an intermediate value of CEF equivalent to recycling 1 electron in 4 from PSI to the plastoquinone pool. Based on this analysis, we conclude that the lack of membrane alkanes causes higher CEF, perhaps for maintenance of redox poise. In turn, increased CEF reduces growth by forcing the cell to use less energy-efficient pathways, lowering the quantum efficiency of photosynthesis. This study highlights the unique and universal role of medium-chain hydrocarbons in cyanobacterial thylakoid membranes: they regulate redox balance and reductant partitioning in these oxygenic photosynthetic cells under stress.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1038/srep14894

Cites

56 of 56 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Cyanobacteria rely on cyclic and pseudo-cyclic electron transport routes to adjust ATP generation, dissipate excess reducing power, and maintain redox poise.

    “However, linear electron flow does not provide unlimited flexibility in this ratio, and cyanobacteria rely on cyclic and pseudo-cyclic electron transport routes to adjust ATP generation, dissipate excess reducing power and maintain redox poise [161].”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Marathe A. & Kallas T. Cyclic Electron Transfer Pathways in Syncechococcus sp. PCC 7002 Cyanobacteria During Photosynthesis At High Light Intensity Master of Science - Biology thesis, The University of Wisconsin Oshkosh (2012).

Cited by

Sorted by citations

Authors
Berla, B. M., Saha, R., Maranas, C. D., & Pakrasi, H. B.
Affiliations
  • Washington University in St. Louis (US)
  • Pennsylvania State University (US)
Corresponding author
Pakrasi, Himadri B.
Venue
Scientific Reports
Published
2015-10-13
Volume
5
Issue
1
Pages
14894-14894
ISSN
2045-2322 (ISSN-L)
OpenAlex
W2415430474
Cited by
76
References
56
Citations by year
2026: 6 · 2025: 15 · 2024: 7 · 2023: 7 · 2022: 6 · 2021: 8 · 2020: 8 · 2019: 7 · 2018: 5 · 2017: 3 · 2016: 4
FWCI
1.74
Type
journal article
Language
en
Open access
Locations
  • Scientific Reports (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) (submittedVersion)
  • Lincoln (University of Nebraska) (submittedVersion, cc-by)
Funders
  • U.S. Department of Energy (DEFG0200ER41132)
  • Office of Science
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Photosynthetic Processes and Mechanisms
  • Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biochemistry › Lipid metabolism and biosynthesis
Keywords
cyclic electron flow, cold stress, Synechocystis sp. PCC 6803, thylakoid membranes, ATP/NADPH ratio, redox homeostasis, flux balance analysis, photosynthetic quantum efficiency
MeSH terms
Adenosine Triphosphate, Cyanobacteria, Alkanes, Cold Temperature, Electron Transport, Kinetics, Mutation, NADP, Oxidation-Reduction, Photosynthesis, Stress, Physiological, Gene Knockout Techniques

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review