Sökning: WFRF:(Lavik G.) >
Simple approach for...
Simple approach for the preparation of N-15-15(2)-enriched water for nitrogen fixation assessments: evaluation, application and recommendations
-
- Klawonn, Isabell (författare)
- Stockholms universitet,Institutionen för ekologi, miljö och botanik
-
Lavik, G. (författare)
-
Boning, P. (författare)
-
visa fler...
-
Marchant, H. K. (författare)
-
Dekaezemacker, J. (författare)
-
Mohr, W. (författare)
-
- Ploug, Helle (författare)
- Stockholms universitet,Gothenburg University,Göteborgs universitet,Institutionen för marina vetenskaper,Department of marine sciences,Institutionen för ekologi, miljö och botanik
-
visa färre...
-
(creator_code:org_t)
- 2015-08-04
- 2015
- Engelska.
-
Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 6
- Relaterad länk:
-
https://www.frontier...
-
visa fler...
-
https://doi.org/10.3...
-
https://gup.ub.gu.se...
-
https://doi.org/10.3...
-
https://urn.kb.se/re...
-
visa färre...
Abstract
Ämnesord
Stäng
- Recent findings revealed that the commonly used N-15(2) tracer assay for the determination of dinitrogen (N-2) fixation can underestimate the activity of aquatic N-2-fixing organisms. Therefore, a modification to the method using pre-prepared N-15-15(2)-enriched water was proposed. Here, we present a rigorous assessment and outline a simple procedure for the preparation of N-15-15(2)-enriched water. We recommend to fill sterile-filtered water into serum bottles and to add N-15-15(2) gas to the water in amounts exceeding the standard N-2 solubility, followed by vigorous agitation (vortex mixing >= 5 min). Optionally, water can be degassed at low-pressure (>= 950 mbar) for 10 mm prior to the N-15-15(2) gas addition to indirectly enhance the N-15-15(2) concentration. This preparation of N-15-15(2)-enriched water can be done within 1 h using standard laboratory equipment. The final N-15-atom% excess was 5% after replacing 2-5% of the incubation volume with N-15-15(2)-enriched water. Notably, the addition of N-15-15(2)-enriched water can alter levels of trace elements in the incubation water due to the contact of N-15-15(2)-enriched water with glass, plastic and rubber ware. In our tests, levels of trace elements (Fe, P, Mn, Mo, Cu, Zn) increased by up to 0.1 nmol L-1 in the final incubation volume, which may bias rate measurements in regions where N-2 fixation is limited by trace elements. For these regions, we tested an alternative way to enrich water with N-15-15(2). The N-15-15(2) was injected as a bubble directly to the incubation water, followed by gentle shaking. Immediately thereafter, the bubble was replaced with water to stop the N-15-15(2) equilibration. This approach achieved a N-15-atom% excess of 6.6 +/- 1.7% when adding 2 mL N-15-15(2) per liter of incubation water. The herein presented methodological tests offer guidelines for the N-15(2) tracer assay and thus, are crucial to circumvent methodological draw-backs for future N-2 fixation assessments.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences (hsv//eng)
- NATURVETENSKAP -- Biologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences (hsv//eng)
Nyckelord
- N-2 fixation
- cyanobacteria
- gas-liquid solution
- N-15(2) gas
- gas solubility
- iron
- phosphorus
- DINITROGEN-FIXATION
- NORTH-ATLANTIC
- OCEAN
- PATTERNS
- PACIFIC
- Microbiology
- N-2 fixation
- Marine Ecology
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas