文章基本信息

标题：Symbiotic unicellular cyanobacteria fix nitrogen in the Arctic Ocean
作者：Katie Harding ; Kendra A. Turk-Kubo ; Rachel E. Sipler 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2018
卷号：115
期号：52
页码：13371-13375
DOI：10.1073/pnas.1813658115
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Biological dinitrogen (N₂) fixation is an important source of nitrogen (N) in low-latitude open oceans. The unusual N₂-fixing unicellular cyanobacteria (UCYN-A)/haptophyte symbiosis has been found in an increasing number of unexpected environments, including northern waters of the Danish Straight and Bering and Chukchi Seas. We used nanoscale secondary ion mass spectrometry (nanoSIMS) to measure ¹⁵N₂ uptake into UCYN-A/haptophyte symbiosis and found that UCYN-A strains identical to low-latitude strains are fixing N₂ in the Bering and Chukchi Seas, at rates comparable to subtropical waters. These results show definitively that cyanobacterial N₂ fixation is not constrained to subtropical waters, challenging paradigms and models of global N₂ fixation. The Arctic is particularly sensitive to climate change, and N₂ fixation may increase in Arctic waters under future climate scenarios.
关键词：nitrogen fixation ; marine microbiology ; Arctic ; cyanobacteria ; nanoSIMS