期刊
LIMNOLOGY AND OCEANOGRAPHY
卷 59, 期 2, 页码 623-637出版社
WILEY
DOI: 10.4319/lo.2014.59.2.0623
关键词
-
资金
- project Shelf-ocean Exchange in the Canaries Iberian Large Marine Ecosystem'' [CTM2007-66408-CO2-O2]
- Ramon y Cajal grant
- project Cyanobacteria: Dominating the Functioning of Oceanic Deserts'' [CTM2008-00915-E]
- project Atmospheric N2 fixation in Posidonia oceanica meadows in the Mediterranean Sea: Diversity, Rates of fixation and Fate of N2'' [CTM2011-23538]
- Formacion de Personal Investigador fellowship [BES-2008-006985]
- Spanish Ministry of Science and Innovation (MICINN)
- Spanish Ministry of Education, Culture and Sports (MECD) under the Campus Program for International Excellence
The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00 degrees N; 9.01 to 20.02 degrees W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to upwelling areas and a temperature range of 13.1 degrees C to 24.2 degrees C) were size fractionated and analyzed for nifH by a nested polymerase chain reaction (PCR) and by tyramide signal amplification-fluorescence in situ hybridization (TSA-FISH) using probe Nitro821. In samples from the surface, mixed-layer depth, and deep chlorophyll maximum waters, most (> 50%) of the nifH recovered was from the 0.2-3 mu m fraction and was consistent with TSA-FISH counts. The < 3 mu m Nitro821-positive cells were more abundant than the larger cells, and the proportion of single cells was larger than that associated with particulate matter or with larger cells. Phylogenetic analysis of representative samples revealed that most of the sequences belong to diazotrophic unicellular cyanobacteria Group A (UCYN-A or Candidatus Atelocyanobacterium thalassa). N-2 fixation in the 0.2-3 mu m fraction, putatively representing the activity of UCYN-A, contributed more than 50% of the total N-2 fixation. There was a positive relationship of this putative UCYN-A abundance and activity with temperature, and a negative relationship with dissolved O-2. The dominance of these putative UCYN-A organisms in nitrate-rich upwelling filament regions suggests that the activity of this group of organisms may not be strongly controlled by the availability of fixed N.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据