scholarly journals Short-term effects of flooding on bacterial ­community structure and nitrogenase activity in microbial mats from a desert stream

2011 ◽  
Vol 63 (3) ◽  
pp. 245-254 ◽  
Author(s):  
RMM Abed ◽  
S Al Kindi ◽  
A Schramm ◽  
MJ Barry
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Microbial Mats ◽  
Nitrogenase Activity ◽  
Short Term ◽  
Short Term Effects ◽  
Desert Stream

scholarly journals Cumulative Effects of Short-Term Polymetal Contamination on Soil Bacterial Community Structure

2006 ◽  
Vol 72 (2) ◽  
pp. 1684-1687 ◽  
Author(s):  
L. Ranjard ◽  
L. Lignier ◽  
R. Chaussod
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Biological Diversity ◽  
Cumulative Effect ◽  
Principal Component ◽  
Soil Bacterial Community ◽  
Short Term ◽  
Soil Bacterial Community Structure ◽  
Soil Bacterial

ABSTRACT In this study we evaluated the short-term effects of copper, cadmium, and mercury, added singly or in combination at different doses, on soil bacterial community structure using the bacterial automated ribosomal intergenic spacer analysis (B-ARISA) fingerprinting technique. Principal-component analysis of B-ARISA profiles allowed us to deduce the following order of impact: (Cu + Cd + Hg) >> Hg ≥ Cd > Cu. These results demonstrated that there was a cumulative effect of metal toxicity. Furthermore, the trend of modifications was consistent with the “hump-backed” relationships between biological diversity and disturbance described by Giller et al. (K. E. Giller, E. Witler, and S. P. McGrath, Soil Biol. Biochem. 30:1389-1414, 1998).

scholarly journals Resilience of planktonic bacterial community structure in response to short-term weather deterioration during the growing season in an alpine lake

Hydrobiologia ◽  
2019 ◽  
Vol 847 (2) ◽  
pp. 535-548
Author(s):  
Tianli Ma ◽  
Yiming Jiang ◽  
Ali H. A. Elbehery ◽  
Stephan Blank ◽  
Rainer Kurmayer ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Bacterial Community Structure ◽  
Bacterial Community Composition ◽  
Growing Season ◽  
Alpine Lake ◽  
Scaling Analysis ◽  
Short Term ◽  
Cooling Period

AbstractThe disturbing effect of a short-term cooling period during summer on planktonic bacterial community structure of an alpine lake was investigated using 16S rDNA pyrosequencing. Proteobacteria, Actinobacteria, and Bacteroidetes constituted the most abundant phyla. During the sampling period (from July to August 2010), a sudden cooling period with high precipitation occurred, as indicated by a decrease in conductivity, calcium, and dissolved organic carbon concentration resulting from increased runoff. The relative abundance of Actinobacteria, Betaproteobacteria, and Cyanobacteria decreased during this short-term cooling period. Instead, a rapid shift from Betaproteobacteria to Gammaproteobacteria occurred, which was mainly caused by an increase of Acinetobacter rhizosphaerae. Soon after the short-term cooling period, warmer weather conditions got re-established and Betaproteobacteria recovered and became again dominant. Non-metric multi-dimensional scaling analysis and Venn diagrams revealed a planktonic bacterial community composition with high similarity at the beginning and the end of the growing season. Air temperature and precipitation were significantly correlated with the observed variation in operational taxonomic unit (OTU) relative abundance. It is concluded that, in response to the short-term cooling period, a distinct planktonic bacterial OTU community developed. It rapidly diminished, however, as summer conditions became re-established, implying the recovery of the original bacterial community structure.

The biogeochemistry of meltwater habitats in the Darwin Glacier region (80°S), Victoria Land, Antarctica

2010 ◽  
Vol 22 (6) ◽  
pp. 646-661 ◽  
Author(s):  
J. Webster-Brown ◽  
M. Gall ◽  
J. Gibson ◽  
S. Wood ◽  
I. Hawes
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Microbial Mats ◽  
Nutrient Status ◽  
Climatic Conditions ◽  
Victoria Land ◽  
Terrestrial Rock ◽  
Finger Printing ◽  
Dna Finger Printing

AbstractMeltwater habitats in the Darwin Glacier region, Victoria Land (80°S), were sampled in December 2007 and January 2009 to characterize their microbial and metazoan ecology, nutrient status and geochemistry. Targeted areas included terrestrial ponds of the Grant Valley, Lake Wellman, Tentacle Ridge and Diamond Hill, and supraglacial ponds and cryoconite holes of the lower Darwin Glacier. Geochemistry ranged from Na-Cl dominated terrestrial ponds to Na-HCO3dominated, dilute supraglacial ponds and cryoconites. All showed the nitrate enrichment typical of inland ponds of Victoria Land (up to 13 g.l-1NO3-N), with some precipitating nitratine (NaNO3) salt. Elevated pH indicated ongoing photosynthetic processes. Benthic microbial mats were thin and poorly developed, dominated by oscillatoriacean cyanobacteria. Nitrogen-fixing genera were generally absent and diatoms were rare. A large (20 μm long)Cyanothecespecies was the most abundant cyanobacterium in the water and in sediments of the cryoconites. DNA finger-printing identified distinct differences in cyanobacterial and bacterial community structure between the cryoconites, terrestrial ponds and ponds on glacial margins. Eleven metazoan species were identified, with rotifers being the most abundant. Pond substrate (terrestrial rock, ice-cored moraine or supraglacial ice) proved to be a more significant influence on biogeochemistry than other aspects of geography or climatic conditions.

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