Identity and dynamics of putative N2-fixing picoplankton in the Baltic Sea proper suggest complex patterns of regulation

被引:39
作者
Farnelid, Hanna [1 ]
Oeberg, Tomas [1 ]
Riemann, Lasse [1 ]
机构
[1] Univ Kalmar, Dept Nat Sci, SE-39182 Kalmar, Sweden
基金
瑞典研究理事会;
关键词
NITROGEN-FIXING MICROORGANISMS; NIFH GENES; CHESAPEAKE BAY; DIAZOTROPHIC CYANOBACTERIA; N-2; FIXATION; EXPRESSION; DIVERSITY; BACTERIA; ATLANTIC; AMPLIFICATION;
D O I
10.1111/j.1758-2229.2009.00021.x
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Heterocystous filamentous cyanobacteria are regarded as the main N-2-fixing organisms (diazotrophs) in the Baltic Sea. However, some studies indicate that picoplankton may also be important. The aim of this study was to examine the composition of putative diazotrophs in the picoplankton (< 3 mu m) and to identify links to environmental factors. Nitrogenase (nifH) genes were amplified from community DNA by nested PCR, followed by cloning and sequencing. Clone libraries from nine environmental samples collected from the central Baltic Sea (April-October 2003, 3 m depth) and a negative control yielded a total of 433 sequences with an average clone library coverage of 92%. The sequences fell within nifH Clusters I, II and III and formed 15 distinct groups (> 96% amino acid similarity). Most of the sequences (77%) fell into nifH Cluster I (cyanobacteria and alpha-, beta- and gamma-Proteobacteria). However, only 26 sequences were related to cyanobacteria (e. g. Pseudanabaena) and among these no unicellular phylotypes were found. Sequences clustering with alternative nitrogenases (anfH) and Archaea were found in one sample while sequences related to anaerobic phylotypes were found in six samples distributed throughout the season. The identified phylogenetic groups showed covariance with several environmental factors but no strong links could be established. This suggests a variable and complex regulation of diazotrophic groups within Baltic Sea picoplankton.
引用
收藏
页码:145 / 154
页数:10
相关论文
共 62 条
[1]   Phenotypic and genetic diversification of Pseudanabaena spp. (cyanobacteria) [J].
Acinas, Silvia G. ;
Haverkamp, Thomas H. A. ;
Huisman, Jef ;
Stal, Lucas J. .
ISME JOURNAL, 2009, 3 (01) :31-46
[2]  
Affourtit J, 2001, MICROBIAL ECOL, V41, P114
[3]   Persistence of selected Spartina alterniflora rhizoplane diazotrophs exposed to natural and manipulated environmental variability [J].
Bagwell, CE ;
Lovell, CR .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2000, 66 (11) :4625-4633
[4]   Evolution of microbial genomes: Sequence acquisition and loss [J].
Berg, OG ;
Kurland, CG .
MOLECULAR BIOLOGY AND EVOLUTION, 2002, 19 (12) :2265-2276
[5]   Spatial distribution and transcriptional activity of an uncultured clade of planktonic diazotrophic γ-proteobacteria in the Arabian Sea [J].
Bird, C ;
Martinez, JM ;
O'Donnell, AG ;
Wyman, M .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2005, 71 (04) :2079-2085
[6]   Nodularia sp nifH gene transcripts in the Baltic Sea proper [J].
Bostrom, Kjarstin H. ;
Riemann, Lasse ;
Zweifel, Ulla Li ;
Hagstrom, Ake .
JOURNAL OF PLANKTON RESEARCH, 2007, 29 (04) :391-399
[7]   Isolation and gene quantification of heterotrophic N2-fixing bacterioplankton in the Baltic Sea [J].
Bostrom, Kjarstin H. ;
Riemann, Lasse ;
Kuhl, Michael ;
Hagstrom, Ake .
ENVIRONMENTAL MICROBIOLOGY, 2007, 9 (01) :152-164
[8]   Molecular evidence for zooplankton-associated nitrogen-fixing anaerobes based on amplification of the nifH gene [J].
Braun, ST ;
Proctor, LM ;
Zani, S ;
Mellon, MT ;
Zehr, JP .
FEMS MICROBIOLOGY ECOLOGY, 1999, 28 (03) :273-279
[9]  
Brown MM, 2003, FEMS MICROBIOL ECOL, V43, P411, DOI 10.1111/j.1574-6941.2003.tb01081.x
[10]   Trichodesmium, a globally significant marine cyanobacterium [J].
Capone, DG ;
Zehr, JP ;
Paerl, HW ;
Bergman, B ;
Carpenter, EJ .
SCIENCE, 1997, 276 (5316) :1221-1229