کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4487474 1317031 2005 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterization of nitrogen-fixing cyanobacteria in the Brazilian Amazon floodplain
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Characterization of nitrogen-fixing cyanobacteria in the Brazilian Amazon floodplain
چکیده انگلیسی

The diversity of the free-living nitrogen-fixing cyanobacterial community in the floodplain sediments along the Solimões and Amazon Rivers and some of their tributaries (Japurá, Negro and Madeira) was investigated. Five cyanobacterial genera were morphologically identified, four of which (Nostoc, Calothrix, Cylindrospermum and Fischerella) have not previously been isolated from the Brazilian Amazon floodplain. Nostoc strains were the most commonly found heterocyst-forming cyanobacteria. Five strains (N. muscorum CENA18 and CENA61, N. piscinale CENA21, Cylindrospermum sp. CENA33 and Fischerella sp. CENA19) were selected for growth measurement, ability to fix N2 and phylogenetic analysis, based on their widespread distribution and morphological distinction. Molecular analyses employing 16S rRNA sequences indicated that some of the isolates may represent novel cyanobacterial species. Dinitrogen fixed by these strains was measured indirectly as acetylene reduction activity and ranged from 11.5 to 22.2 nmol C2H4 μg Chl a−1 h−1. These results provide evidence of widespread and importance of nitrogen-fixing cyanobacteria as a source of N inputs in the Amazonian ecosystem.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Water Research - Volume 39, Issue 20, December 2005, Pages 5017–5026
نویسندگان
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