Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1093/femsec/fiv131 |
| Title (Primary) | High cell-specific rates of nitrogen and carbon fixation by the cyanobacterium Aphanizomenon sp. at low temperatures in the Baltic Sea |
| Author | Svedén, J.B.; Adam, B.; Walve, J.; Nahar, N.; Musat, N.; Lavik, G.; Whitehouse, M.J.; Kuypers, M.M.M.; Ploug, H. |
| Source Titel | FEMS Microbiology Ecology |
| Year | 2015 |
| Department | ISOBIO |
| Volume | 91 |
| Issue | 12 |
| Page From | fiv131 |
| Language | englisch |
| Supplements | Supplement 1 |
| Keywords | Aphanizomenon; SIMS; isotopes; O2-microsensors; C-fixation; N2-fixation |
| UFZ wide themes | RU3; |
| Abstract | Aphanizomenon is a widespread genus of nitrogen (N2)-fixing cyanobacteria in lakes and estuaries, accounting for a large fraction of the summer N2-fixation in the Baltic Sea. However, information about its cell-specific carbon (C)- and N2-fixation rates in the early growth season has not previously been reported. We combined various methods to study N2-fixation, photosynthesis and respiration in field-sampled Baltic Sea Aphanizomenon sp. during early summer at 10°C. Stable isotope incubations at in situ light intensities during 24 h combined with cell-specific secondary ion mass spectrometry showed an average net N2-fixation rate of 55 fmol N cell−1 day−1. Dark net N2-fixation rates over a course of 12 h were 20% of those measured in light. C-fixation, but not N2-fixation, was inhibited by high ambient light intensities during daytime. Consequently, the C:N fixation ratio varied substantially over the diel cycle. C- and N2-fixation rates were comparable to those reported for Aphanizomenon sp. in August at 19°C, using the same methods. High respiration rates (23% of gross photosynthesis) were measured with 14C-incubations and O2-microsensors, and presumably reflect the energy needed for high N2-fixation rates. Hence, Aphanizomenon sp. is an important contributor to N2-fixation at low in situ temperatures in the early growth season. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=17046 |
| Svedén, J.B., Adam, B., Walve, J., Nahar, N., Musat, N., Lavik, G., Whitehouse, M.J., Kuypers, M.M.M., Ploug, H. (2015): High cell-specific rates of nitrogen and carbon fixation by the cyanobacterium Aphanizomenon sp. at low temperatures in the Baltic Sea FEMS Microbiol. Ecol. 91 (12), fiv131 10.1093/femsec/fiv131 |
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