scholarly journals Temporal and Spatial Patterns of Eukaryotic and Bacterial Communities Found in Vernal Pools

2008 ◽  
Vol 74 (8) ◽  
pp. 2554-2557 ◽  
Author(s):  
Sarah R. Carrino-Kyker ◽  
Andrew K. Swanson

ABSTRACT In this study, we examined the effects of physicochemical variability on the microbial communities of vernal pools. Denaturing gradient gel electrophoresis revealed temporal changes to be more pronounced than spatial changes in eukaryotic and bacterial communities. Sequencing revealed high degrees of richness in decomposers, which supports the notion that vernal pools are heterotrophic habitats.

Author(s):  
Márton Mucsi ◽  
Gergely Krett ◽  
Tibor Szili-Kovács ◽  
János Móga ◽  
Andrea K. Borsodi

Abstract Soils play an important role in the ecosystem of karstic landscapes both as a buffer zone and as a source of acidity to belowground water. Although the microbiota of karstic soils is known to have a great effect on karstification processes, the activity and composition of these communities are largely unknown. This study gives a comparative analysis of soil microbial profiles from different parts of a doline located at Aggtelek, Hungary. The aim was to reveal the relationships between the vegetation type and genetic fingerprints and substrate utilisation (multi-SIR) profiles of the soil microbiota. Soil samples were collected in early and late springs along a transect in a doline covered with different types of vegetation. Genetic fingerprints of bacterial communities were examined by denaturing gradient gel electrophoresis (DGGE) based on the 16S rRNA gene, along with multi-SIR profiles of the microbial communities measured by the MicroResp method using 15 different carbon sources. Genetic fingerprinting indicated that vegetation cover had a strong effect on the composition of soil bacterial communities. Procrustean analysis showed only a weak connection between DGGE and multi-SIR profiles, probably due to the high functional redundancy of the communities. Seasonality had a significant effect on substrate usage, which can be an important factor to consider in future studies.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Qiufen Li ◽  
Yan Zhang ◽  
David Juck ◽  
Nathalie Fortin ◽  
Charles W. Greer

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.


2009 ◽  
Vol 55 (No. 10) ◽  
pp. 413-423 ◽  
Author(s):  
V. Valášková ◽  
P. Baldrian

In soil microbial ecology, the effects of environmental factors and their gradients, temporal changes or the response to specific experimental treatments of microbial communities can only be effectively analyzed using methods that address the structural differences among whole communities. Fingerprinting methods are the most appropriate technique for this task when multiple samples must be analyzed. Among the methods currently used to compare microbial communities based on nucleic acid sequences, the techniques based on differences in the melting properties of double-stranded molecules, denaturing gradient gel electrophoresis (DGGE) or temperature gradient gel electrophoresis (TGGE), are the most widely used. Their main advantage is that they provide the possibility to further analyze whole sequences contained in fingerprints using molecular methods. In addition to the analysis of microbial communities based on DNA extracted from soils, DGGE/TGGE can also be used for the assessment of the active part of the community based on the analysis of RNA-derived sequences or for the analysis of sequences of functional genes encoding for proteins involved in important soil processes.


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