期刊
WATER RESEARCH
卷 39, 期 20, 页码 5017-5026出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.watres.2005.10.002
关键词
amazon floodplain; cyanobacteria; 16S rRNA; N-2; fixation
The diversity of the free-living nitrogen-fixing cyanobacterial community in the floodplain sediments along the Solimoes and Amazon Rivers and some of their tributaries (Japura, 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 N-2 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 mu g 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. (c) 2005 Elsevier Ltd. All rights reserved.
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