Carbon and nitrogen fixation and metabolite exchange in and between individual cells of <i>Anabaena oscillarioides</i>

Popa, Radu; Weber, Peter K.; Pett‐Ridge, Jennifer; Finzi, J. A.; Fallon, Stewart; Hutcheon, I. D.; Nealson, Kenneth H.; Capone, Douglas G.

doi:10.1038/ismej.2007.44

Cited by 152 publications

(215 citation statements)

References 23 publications

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“…This has also been observed in natural populations of other phototrophic microorganisms (Musat et al, 2008). Within trichomes, we measured a rapid transfer of fixed nitrogen from heterocysts to vegetative cells also reported in Anabaena oscillarioides cultures (Popa et al, 2007). Generally, the 15 N label intensity in the heterocysts was low compared with that of the vegetative cells.…”

Section: Discussionmentioning

confidence: 72%

Carbon and nitrogen fluxes associated with the cyanobacterium Aphanizomenon sp. in the Baltic Sea

et al. 2010

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Carbon and nitrogen fluxes in Aphanizomenon sp. colonies in the Baltic Sea were measured using a combination of microsensors, stable isotopes, mass spectrometry, and nanoscale secondary ion mass spectrometry (nanoSIMS). Cell numbers varied between 956 and 33 000 in colonies ranging in volume between 1.4 Â 10 À4 and 230 Â 10 À4 mm À3 . The high cell content and their productivity resulted in steep O 2 gradients at the colony-water interface as measured with an O 2 microsensor. Colonies were highly autotrophic communities with few heterotrophic bacteria attached to the filaments. Volumetric gross photosynthesis in colonies was 78 nmol O 2 mm À3 h À1 . Net photosynthesis was 64 nmol O 2 mm À3 h À1 , and dark respiration was on average 15 nmol O 2 mm À3 h À1 or 16% of gross photosynthesis. These volumetric photosynthesis rates belong to the highest measured in aquatic systems. The average cell-specific net carbon-fixation rate was 38 and 40 fmol C cell À1 h À1 measured by microsensors and by using stable isotopes in combination with mass spectrometry and nanoSIMS, respectively. In light, the net C:N fixation ratio of individual cells was 7.3±3.4. Transfer of fixed N 2 from heterocysts to vegetative cells was fast, but up to 35% of the gross N 2 fixation in light was released as ammonium into the surrounding water. Calculations based on a daily cycle showed a net C:N fixation ratio of 5.3. Only 16% of the bulk N 2 fixation in dark was detected in Aphanizomenon sp. Hence, other organisms appeared to dominate N 2 fixation and NH 4 þ release during darkness.

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Section: Discussionmentioning

confidence: 72%

Carbon and nitrogen fluxes associated with the cyanobacterium Aphanizomenon sp. in the Baltic Sea

et al. 2010

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“…1). This temporal pattern has been shown by Gallon et al (2002) and recently by Popa et al (2007) using the heterocystic cyanobacterium Anabaena.…”

Section: Endogenous Control and Diel Patternmentioning

confidence: 87%

Release of fixed N2 and C as dissolved compounds by Trichodesmium erythreum and Nodularia spumigena under the influence of high light and high nutrient (P)

Wannicke¹,

Koch²,

Voß³

2009

Aquat. Microb. Ecol.

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Diel variations of N 2 and C fixation rates, as well as subsequent release of total dissolved N (TDN) and dissolved organic carbon (DOC) were determined for Trichodemsium erythreum and Nodularia spumigena. A circadian rhythm of N 2 and C fixation, as well as a periodicity in the calculated release of dissolved compounds, was observed. From the amounts of N and inorganic C fixed by T. erythreum during the light period of the experiment, 71 and 50% were released as TDN and DOC, respectively; for N. spumigena we found a release of 89 and 53%, respectively, during the light period. Additionally, 2 controlling factors (light and nutrient concentrations) for the release of TDN and DOC were studied. The data suggest that rapid shifts towards higher light intensity lead to a pronounced exudation of TDN and DOC. On a short-term basis (first 30 min after exposure), the exudation of NH 4 + and DON consumed up to 52% of electrons harvested by the cells in the same time interval. Thus TDN release serves as a potential electron sink and protects cells from photodestruction. On the other hand, there was no clear effect of phosphorus concentration on the release of TDN and DOC. Our results indicate that uptake and subsequent exudation of TDN and DOC might be induced by abiotic parameters, besides being regulated endogenously by multiple feedback loops.

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“…(Ploug et al, 2010) as well as Anabaena sp. (Popa et al, 2007). Both the cell-specific net C-and N 2 -fixation rates by N. spumigena were ca.…”

Section: Discussionmentioning

confidence: 98%

Carbon, nitrogen and O2 fluxes associated with the cyanobacterium Nodularia spumigena in the Baltic Sea

et al. 2011

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Photosynthesis, respiration, N 2 fixation and ammonium release were studied directly in Nodularia spumigena during a bloom in the Baltic Sea using a combination of microsensors, stable isotope tracer experiments combined with nanoscale secondary ion mass spectrometry (nanoSIMS) and fluorometry. Cell-specific net C-and N 2 -fixation rates by N. spumigena were 81.6±6.7 and 11.4 ± 0.9 fmol N per cell per h, respectively. During light, the net C:N fixation ratio was 8.0 ± 0.8. During darkness, carbon fixation was not detectable, but N 2 fixation was 5.4 ± 0.4 fmol N per cell per h. Net photosynthesis varied between 0.34 and 250 nmol O 2 h À1 in colonies with diameters ranging between 0.13 and 5.0 mm, and it reached the theoretical upper limit set by diffusion of dissolved inorganic carbon to colonies (41 mm). Dark respiration of the same colonies varied between 0.038 and 87 nmol O 2 h À1 , and it reached the limit set by O 2 diffusion from the surrounding water to colonies (41 mm). N 2 fixation associated with N. spumigena colonies (41 mm) comprised on average 18% of the total N 2 fixation in the bulk water. Net NH 4 þ release in colonies equaled 8-33% of the estimated gross N 2 fixation during photosynthesis. NH 4 þ concentrations within light-exposed colonies, modeled from measured net NH 4 þ release rates, were 60-fold higher than that of the bulk. Hence, N. spumigena colonies comprise highly productive microenvironments and an attractive NH 4 þ microenvironment to be utilized by other (micro)organisms in the Baltic Sea where dissolved inorganic nitrogen is limiting growth.

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Carbon and nitrogen fixation and metabolite exchange in and between individual cells of Anabaena oscillarioides

Cited by 152 publications

References 23 publications

Carbon and nitrogen fluxes associated with the cyanobacterium Aphanizomenon sp. in the Baltic Sea

Carbon and nitrogen fluxes associated with the cyanobacterium Aphanizomenon sp. in the Baltic Sea

Release of fixed N2 and C as dissolved compounds by Trichodesmium erythreum and Nodularia spumigena under the influence of high light and high nutrient (P)

Carbon, nitrogen and O2 fluxes associated with the cyanobacterium Nodularia spumigena in the Baltic Sea

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