Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Electron & Biomass Dynamics of Cyanothece Under Interacting Nitrogen & Carbon Limitations


Eichner,  Meri
Permanent Research Group Microsensor, Max Planck Institute for Marine Microbiology, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)

(Publisher version), 5MB

Supplementary Material (public)
There is no public supplementary material available

Rabouille, S., Campbell, D. A., Masuda, T., Zavrel, T., Bernat, G., Polerecky, L., et al. (2021). Electron & Biomass Dynamics of Cyanothece Under Interacting Nitrogen & Carbon Limitations. FRONTIERS IN MICROBIOLOGY, 12: 617802. doi:10.3389/fmicb.2021.617802.

Cite as: https://hdl.handle.net/21.11116/0000-0009-8238-5
Marine diazotrophs are a diverse group with key roles in biogeochemical fluxes linked to primary productivity. The unicellular, diazotrophic cyanobacterium Cyanothece is widely found in coastal, subtropical oceans. We analyze the consequences of diazotrophy on growth efficiency, compared to NO3--supported growth in Cyanothece, to understand how cells cope with N-2-fixation when they also have to face carbon limitation, which may transiently affect populations in coastal environments or during blooms of phytoplankton communities. When grown in obligate diazotrophy, cells face the double burden of a more ATP-demanding N-acquisition mode and additional metabolic losses imposed by the transient storage of reducing potential as carbohydrate, compared to a hypothetical N-2 assimilation directly driven by photosynthetic electron transport. Further, this energetic burden imposed by N-2-fixation could not be alleviated, despite the high irradiance level within the cultures, because photosynthesis was limited by the availability of dissolved inorganic carbon (DIC), and possibly by a constrained capacity for carbon storage. DIC limitation exacerbates the costs on growth imposed by nitrogen fixation. Therefore, the competitive efficiency of diazotrophs could be hindered in areas with insufficient renewal of dissolved gases and/or with intense phytoplankton biomass that both decrease available light energy and draw the DIC level down.