@misc{10498/27549,
year = {2022},
month = {7},
url = {http://hdl.handle.net/10498/27549},
abstract = {Identifying and quantifying nitrogen pools is essential for understanding the nitrogen cycle in aquatic ecosystems. The ubiquitous diatoms represent an overlooked nitrate pool as they can accumulate nitrate intracellularly and utilize it for nitrogen assimilation, dissipation of excess photosynthetic energy, and Dissimilatory Nitrate Reduction to Ammonium (DNRA). Here, we document the global co-occurrence of diatoms and intracellular nitrate in phototrophic microbial communities in freshwater (n = 69), coastal (n = 44), and open marine (n = 4) habitats. Diatom abundance and total intracellular nitrate contents in water columns, sediments, microbial mats, and epilithic biofilms were highly significantly correlated. In contrast, diatom community composition had only a marginal influence on total intracellular nitrate contents. Nitrate concentrations inside diatom cells exceeded ambient nitrate concentrations similar to 100-4000-fold. The collective intracellular nitrate pool of the diatom community accounted for <1% of total nitrate in pelagic habitats and 65-95% in benthic habitats. Accordingly, nitrate-storing diatoms are emerging as significant contributors to benthic nitrogen cycling, in particular through Dissimilatory Nitrate Reduction to Ammonium activity under anoxic conditions.

The accumulation and storage of nitrate by diatoms can contribute up to 1% of total pelagic nitrate and as much as 95% of total benthic nitrate, which indicates a potentially important contribution of diatoms to benthic nitrogen cycling, according to a global analysis},
publisher = {SPRINGERNATURE},
title = {Intracellular nitrate storage by diatoms can be an important nitrogen pool in freshwater and marine ecosystems},
doi = {10.1038/s43247-022-00485-8},
author = {Stief, Peter and Schauberger, Clemens and Lund, Marie B. and Greve, Andreas and Abed, Raeid M. M. and Al-Najjar, Mohammad A. A. and Attard, Karl M. and Bonaglia, Stefano and Deutzmann, Jörg S. and Franco-Cisterna, Belén and García Robledo, Emilio Guillermo and Holtappels, Moritz and John, Uwe and Maciute, Adele and Magee, Michael J. and Pors, Rie and Santl-Temkiv, Tina and Scherwass, Anja and Sevilgen, Duygu S. and de Beer, Dirk and Glud, Ronnie and Schramm, Andreas and Kamp, Anja},
}