CO2 control of Trichodesmium N2 fixation, photosynthesis, growth rates, and elemental ratios: Implications for past, present, and future ocean biogeochemistry

@article{Hutchins2007CO2CO,
  title={CO2 control of Trichodesmium N2 fixation, photosynthesis, growth rates, and elemental ratios: Implications for past, present, and future ocean biogeochemistry},
  author={David A. Hutchins and Fei-xue Fu and Y. Zhang and Mark E. Warner and Y M Feng and Kevin J. Portune and Peter W. Bernhardt and Margaret R. Mulholland},
  journal={Limnology and Oceanography},
  year={2007},
  volume={52}
}
Diazotrophic marine cyanobacteria in the genus Trichodesmium contribute a large fraction of the new nitrogen entering the oligotrophic oceans, but little is known about how they respond to shifts in global change variables such as carbon dioxide (CO2) and temperature. We compared Trichodesmium dinitrogen (N2) and CO2 fixation rates during steady‐state growth under past, current, and future CO2 scenarios, and at two relevant temperatures. At projected CO2 levels of year 2100 (76 Pa, 750 ppm), N2… 

Interactions between changing pCO2, N2 fixation, and Fe limitation in the marine unicellular cyanobacterium Crocosphaera

Physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial, current and projected year 2100 CO 2 levels are examined.

Carbon acquisition by Trichodesmium: the effect of pCO2 and diurnal changes

The findings point to a shift in resource allocation among photosynthesis, carbon acquisition, and N2 fixation under elevated CO2 levels, which could have potential biogeochemical implications, as it may stimulate productivity in N-limited oligotrophic regions and thus provide a negative feedback on rising atmosphericCO2 levels.

Response of Nodularia spumigena to pCO2 - Part 1: Growth, production and nitrogen cycling

It is suggested that rising pCO2 stimulates the growth of heterocystous diazotrophic cyanobacterium Nodularia spumigena, in a similar way as reported for the non-heterocystou diazOTroph Trichodesmium.

Impact of increasing carbon dioxide on dinitrogen and carbon fixation rates under oligotrophic conditions and simulated upwelling

Dinitrogen (N2) fixation is a major source of bioavailable nitrogen to oligotrophic ocean communities. Yet, we have limited understanding how ongoing climate change could alter N2 fixation. Most of

Interactions between CCM and N2 fixation in Trichodesmium

A strong light modulation of CO2 effects further corroborates the role of energy fluxes as a key to understand the responses of Trichodesmium.

Regulation of nitrogen metabolism in the marine diazotroph Trichodesmium IMS101 under varying temperatures and atmospheric CO2 concentrations.

It is proposed that shifted cellular resource and energy allocation among those components will enable Trichodesmium grown at elevated temperatures and pCO(2) to extend its niche in the future ocean, through both tolerance of a broader temperature range and higher P plasticity.

Diversity trumps acidification: Lack of evidence for carbon dioxide enhancement of Trichodesmium community nitrogen or carbon fixation at Station ALOHA

The diverse assemblage of Trichodesmium species and coexisting microorganisms within the colonies can explain the lack of an observed CO2 enhancement of N2 or C fixation rates, because different species are known to have different specific affinities for CO2.

Mechanisms of increased Trichodesmium fitness under iron and phosphorus co-limitation in the present and future ocean

It is suggested that N2-fixing microbes may be significantly impacted by interactions between elevated CO2 and nutrient limitation, with broad implications for global biogeochemical cycles in the future ocean.

No stimulation of nitrogen fixation by non‐filamentous diazotrophs under elevated CO2 in the South Pacific

If nitrogen fixation by UCYN-A is not stimulated by elevated pCO2 , then future increases in CO2 and warming may alter the regional distribution and dominance of different diazotroph groups, with implications for dissolved iron availability and new nitrogen supply in oligotrophic regions.

INTERACTIVE EFFECTS OF IRRADIANCE AND CO2 ON CO2 FIXATION AND N2 FIXATION IN THE DIAZOTROPH TRICHODESMIUM ERYTHRAEUM (CYANOBACTERIA) 1

This study suggests that elevated pCO2 may have a strong positive effect on Trichodesmium gross N2 fixation in intermediate and bottom layers of the euphotic zone, but perhaps not in light‐saturated surface layers.
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