scholarly journals Response of Bacterioplankton Communities to Cadmium Exposure in Coastal Water Microcosms with High Temporal Variability

2014 ◽  
Vol 81 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Kai Wang ◽  
Demin Zhang ◽  
Jinbo Xiong ◽  
Xinxin Chen ◽  
Jialai Zheng ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Coastal Water ◽  
Temporal Variability ◽  
Temporal Dynamics ◽  
Content Type ◽  
Bacterioplankton Community ◽  
Temporal Succession ◽  
Cd Exposure ◽  
Bacterioplankton Communities

ABSTRACTMultiple anthropogenic disturbances to bacterial diversity have been investigated in coastal ecosystems, in which temporal variability in the bacterioplankton community has been considered a ubiquitous process. However, far less is known about the temporal dynamics of a bacterioplankton community responding to pollution disturbances such as toxic metals. We used coastal water microcosms perturbed with 0, 10, 100, and 1,000 μg liter−1of cadmium (Cd) for 2 weeks to investigate temporal variability, Cd-induced patterns, and their interaction in the coastal bacterioplankton community and to reveal whether the bacterial community structure would reflect the Cd gradient in a temporally varying system. Our results showed that the bacterioplankton community structure shifted along the Cd gradient consistently after a 4-day incubation, although it exhibited some resistance to Cd at low concentration (10 μg liter−1). A process akin to an arms race between temporal variability and Cd exposure was observed, and the temporal variability overwhelmed Cd-induced patterns in the bacterial community. The temporal succession of the bacterial community was correlated with pH, dissolved oxygen, NO3−-N, NO2−-N, PO43−-P, dissolved organic carbon, and chlorophylla, and each of these parameters contributed more to community variance than Cd did. However, elevated Cd levels did decrease the temporal turnover rate of community. Furthermore, key taxa, affiliated to the familiesFlavobacteriaceae,Rhodobacteraceae,Erythrobacteraceae,Piscirickettsiaceae, andAlteromonadaceae, showed a high frequency of being associated with Cd levels during 2 weeks. This study provides direct evidence that specific Cd-induced patterns in bacterioplankton communities exist in highly varying manipulated coastal systems. Future investigations on an ecosystem scale across longer temporal scales are needed to validate the observed pattern.

Temporal variability of airborne bacterial community structure in an urban area

2006 ◽  
Vol 40 (40) ◽  
pp. 8074-8080 ◽  
Author(s):  
Pierre A. Maron ◽  
Christophe Mougel ◽  
David P. H. Lejon ◽  
Esmeralda Carvalho ◽  
Karine Bizet ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Urban Area ◽  
Temporal Variability ◽  
Bacterial Community Structure

scholarly journals Restructuring of the Aquatic Bacterial Community by Hydric Dynamics Associated with Superstorm Sandy

2016 ◽  
Vol 82 (12) ◽  
pp. 3525-3536 ◽  
Author(s):  
Nikea Ulrich ◽  
Abigail Rosenberger ◽  
Colin Brislawn ◽  
Justin Wright ◽  
Collin Kessler ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
High Throughput ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Storm Event ◽  
Rrna Gene ◽  
Content Type

ABSTRACTBacterial community composition and longitudinal fluctuations were monitored in a riverine system during and after Superstorm Sandy to better characterize inter- and intracommunity responses associated with the disturbance associated with a 100-year storm event. High-throughput sequencing of the 16S rRNA gene was used to assess microbial community structure within water samples from Muddy Creek Run, a second-order stream in Huntingdon, PA, at 12 different time points during the storm event (29 October to 3 November 2012) and under seasonally matched baseline conditions. High-throughput sequencing of the 16S rRNA gene was used to track changes in bacterial community structure and divergence during and after Superstorm Sandy. Bacterial community dynamics were correlated to measured physicochemical parameters and fecal indicator bacteria (FIB) concentrations. Bioinformatics analyses of 2.1 million 16S rRNA gene sequences revealed a significant increase in bacterial diversity in samples taken during peak discharge of the storm. Beta-diversity analyses revealed longitudinal shifts in the bacterial community structure. Successional changes were observed, in whichBetaproteobacteriaandGammaproteobacteriadecreased in 16S rRNA gene relative abundance, while the relative abundance of members of theFirmicutesincreased. Furthermore, 16S rRNA gene sequences matching pathogenic bacteria, including strains ofLegionella,Campylobacter,Arcobacter, andHelicobacter, as well as bacteria of fecal origin (e.g.,Bacteroides), exhibited an increase in abundance after peak discharge of the storm. This study revealed a significant restructuring of in-stream bacterial community structure associated with hydric dynamics of a storm event.IMPORTANCEIn order to better understand the microbial risks associated with freshwater environments during a storm event, a more comprehensive understanding of the variations in aquatic bacterial diversity is warranted. This study investigated the bacterial communities during and after Superstorm Sandy to provide fine time point resolution of dynamic changes in bacterial composition. This study adds to the current literature by revealing the variation in bacterial community structure during the course of a storm. This study employed high-throughput DNA sequencing, which generated a deep analysis of inter- and intracommunity responses during a significant storm event. This study has highlighted the utility of applying high-throughput sequencing for water quality monitoring purposes, as this approach enabled a more comprehensive investigation of the bacterial community structure. Altogether, these data suggest a drastic restructuring of the stream bacterial community during a storm event and highlight the potential of high-throughput sequencing approaches for assessing the microbiological quality of our environment.

scholarly journals Effect of Dietary Supplementation with a Saccharomyces cerevisiae Mannan Oligosaccharide on the Bacterial Community Structure of Broiler Cecal Contents

2011 ◽  
Vol 77 (18) ◽  
pp. 6653-6662 ◽  
Author(s):  
A. Corrigan ◽  
K. Horgan ◽  
N. Clipson ◽  
R. A. Murphy
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Bacterial Community Structure ◽  
Dietary Supplementation ◽  
Control Group ◽  
Rrna Gene ◽  
Content Type ◽  
Mannan Oligosaccharide

ABSTRACTThis study investigated the effects of dietary supplementation with a prebiotic mannan oligosaccharide (MOS) on broiler performance, bacterial community structure, and phylogenetic populations of cecal contents. Bird performance data were collected, and cecal samples were extracted from randomly caught poults from each treatment group every 7 days from hatching to the age of 42 days. Weight gain, feed consumption, and feed efficiency ratios did not differ significantly between groups. Automated ribosomal intergenic spacer analysis (ARISA) of the bacterial communities in birds receiving MOS-supplemented diets indicated that dietary supplementation with MOS at either of 2 levels significantly altered the bacterial community structure from that of the control group on all sample days. The phylogenetic identities of bacteria contained within the cecum were determined by constructing a 16S rRNA gene clone library. A total of 594 partial 16S rRNA gene sequences from the cecal contents were analyzed and compared for the three dietary treatments. The dominant bacteria of the cecum belonged to three phyla,Firmicutes,Bacteroidetes, andProteobacteria; of these,Firmicuteswere the most dominant in all treatment groups. Statistical analysis of the bacterial 16S rRNA gene clone libraries showed that the compositions of the clone libraries from broilers receiving MOS-supplemented diets were, in most cases, significantly different from that of the control group. It can be concluded that in this trial MOS supplementation significantly altered the cecal bacterial community structure.

scholarly journals Temporal variability is a personalized feature of the human microbiome

2014 ◽  
Author(s):  
Gilberto E Flores ◽  
J Gregory Caporaso ◽  
Jessica B Henley ◽  
Jai Ram Rideout ◽  
Daniel Domogala ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Human Body ◽  
Temporal Variability ◽  
Temporal Dynamics ◽  
Human Microbiome ◽  
Wide Range ◽  
Diverse Communities ◽  
Study Population ◽  
Over Time

Background: It is now apparent that the complex microbial communities found on and in the human body (the human microbiome) vary across individuals. What has largely been missing from previous studies is an understanding of how these communities vary over time within individuals. To the extent to which it has been considered, it is often assumed that temporal variability is negligible for healthy adults. Here we address this gap in understanding by profiling the forehead, gut (fecal), palm, and tongue microbial communities in 85 adults, weekly over three months. Results: We found that skin (forehead and palm) varied most in the number of taxa present, whereas gut and tongue communities varied more in the relative abundances of taxa. Within each body habitat, there was a wide range of temporal variability across the study population, with some individuals consistently harboring more variable communities than others. The best predictor of these differences in variability across individuals was microbial diversity; individuals with more diverse gut or tongue communities were less variable than individuals with less diverse communities. Conclusions: This expanded sampling allowed us to observe consistently high levels of temporal variability in both diversity and community structure in all body habitats studied. These findings suggest that temporal dynamics may need to be considered when attempting to link changes in microbiome structure to changes in health status.Furthermore, our findings show that, not only is the composition of an individual’s microbiome highly personalized, but their degree of temporal variability is also a personalized feature.

scholarly journals Corexit 9500 Enhances Oil Biodegradation and Changes Active Bacterial Community Structure of Oil-Enriched Microcosms

2017 ◽  
Vol 83 (10) ◽  
Author(s):  
Stephen M. Techtmann ◽  
Mobing Zhuang ◽  
Pablo Campo ◽  
Edith Holder ◽  
Michael Elk ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Bacterial Community Structure ◽  
Oil Spills ◽  
Content Type ◽  
Corexit 9500 ◽  
Oil Biodegradation ◽  
Degrading Bacteria ◽  
The Impact

ABSTRACT To better understand the impacts of Corexit 9500 on the structure and activity levels of hydrocarbon-degrading microbial communities, we analyzed next-generation 16S rRNA gene sequencing libraries of hydrocarbon enrichments grown at 5 and 25°C using both DNA and RNA extracts as the sequencing templates. Oil biodegradation patterns in both 5 and 25°C enrichments were consistent with those reported in the literature (i.e., aliphatics were degraded faster than aromatics). Slight increases in biodegradation were observed in the presence of Corexit at both temperatures. Differences in community structure were observed between treatment conditions in the DNA-based libraries. The 25°C consortia were dominated by Vibrio, Idiomarina, Marinobacter, Alcanivorax, and Thalassospira species, while the 5°C consortia were dominated by several species of the genera Flavobacterium, Alcanivorax, and Oleispira. Most of these genera have been linked to hydrocarbon degradation and have been observed after oil spills. Colwellia and Cycloclasticus, known aromatic degraders, were also found in these enrichments. The addition of Corexit did not have an effect on the active bacterial community structure of the 5°C consortia, while at 25°C, a decrease in the relative abundance of Marinobacter was observed. At 25°C, Thalassospira, Marinobacter, and Idiomarina were present at higher relative abundances in the RNA than DNA libraries, suggesting that they were active in degradation. Similarly, Oleispira was greatly stimulated by the addition of oil at 5°C. IMPORTANCE While dispersants such as Corexit 9500 can be used to treat oil spills, there is still debate on the effectiveness on enhancing oil biodegradation and its potential toxic effect on oil-degrading microbial communities. The results of this study provide some insights on the microbial dynamics of hydrocarbon-degrading bacterial populations in the presence of Corexit 9500. Operational taxonomic unit (OTU) analyses indicated that several OTUs were inhibited by the addition of Corexit. Conversely, a number of OTUs were stimulated by the addition of the dispersant, many of which were identified as known hydrocarbon-degrading bacteria. The results highlight the value of using RNA-based methods to further understand the impact of dispersant on the overall activity of different hydrocarbon-degrading bacterial groups.

scholarly journals Bacterial Community Structure of Acid-Impacted Lakes: What Controls Diversity?

2008 ◽  
Vol 74 (6) ◽  
pp. 1856-1868 ◽  
Author(s):  
Sascha F. Percent ◽  
Marc E. Frischer ◽  
Paul A. Vescio ◽  
Ellen B. Duffy ◽  
Vincenzo Milano ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Community Composition ◽  
The United States ◽  
Trophic Levels ◽  
Community Diversity ◽  
Rrna Gene ◽  
Clone Libraries ◽  
Bacterioplankton Community ◽  
Bacterioplankton Communities

ABSTRACT Although it is recognized that acidification of freshwater systems results in decreased overall species richness of plants and animals, little is known about the response of aquatic microbial communities to acidification. In this study we examined bacterioplankton community diversity and structure in 18 lakes located in the Adirondack Park (in the state of New York in the United States) that were affected to various degrees by acidic deposition and assessed correlations with 31 physical and chemical parameters. The pH of these lakes ranged from 4.9 to 7.8. These studies were conducted as a component of the Adirondack Effects Assessment Program supported by the U.S. Environmental Protection Agency. Thirty-one independent 16S rRNA gene libraries consisting of 2,135 clones were constructed from epilimnion and hypolimnion water samples. Bacterioplankton community composition was determined by sequencing and amplified ribosomal DNA restriction analysis of the clone libraries. Nineteen bacterial classes representing 95 subclasses were observed, but clone libraries were dominated by representatives of the Actinobacteria and Betaproteobacteria classes. Although the diversity and richness of bacterioplankton communities were positively correlated with pH, the overall community composition assessed by principal component analysis was not. The strongest correlations were observed between bacterioplankton communities and lake depth, hydraulic retention time, dissolved inorganic carbon, and nonlabile monomeric aluminum concentrations. While there was not an overall correlation between bacterioplankton community structure and pH, several bacterial classes, including the Alphaproteobacteria, were directly correlated with acidity. These results indicate that unlike more identifiable correlations between acidity and species richness for higher trophic levels, controls on bacterioplankton community structure are likely more complex, involving both direct and indirect processes.

scholarly journals Temporal variability is a personalized feature of the human microbiome

2014 ◽  
Author(s):  
Gilberto E Flores ◽  
J Gregory Caporaso ◽  
Jessica B Henley ◽  
Jai Ram Rideout ◽  
Daniel Domogala ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Human Body ◽  
Temporal Variability ◽  
Temporal Dynamics ◽  
Human Microbiome ◽  
Wide Range ◽  
Diverse Communities ◽  
Study Population ◽  
Over Time

Background: It is now apparent that the complex microbial communities found on and in the human body (the human microbiome) vary across individuals. What has largely been missing from previous studies is an understanding of how these communities vary over time within individuals. To the extent to which it has been considered, it is often assumed that temporal variability is negligible for healthy adults. Here we address this gap in understanding by profiling the forehead, gut (fecal), palm, and tongue microbial communities in 85 adults, weekly over three months. Results: We found that skin (forehead and palm) varied most in the number of taxa present, whereas gut and tongue communities varied more in the relative abundances of taxa. Within each body habitat, there was a wide range of temporal variability across the study population, with some individuals consistently harboring more variable communities than others. The best predictor of these differences in variability across individuals was microbial diversity; individuals with more diverse gut or tongue communities were less variable than individuals with less diverse communities. Conclusions: This expanded sampling allowed us to observe consistently high levels of temporal variability in both diversity and community structure in all body habitats studied. These findings suggest that temporal dynamics may need to be considered when attempting to link changes in microbiome structure to changes in health status.Furthermore, our findings show that, not only is the composition of an individual’s microbiome highly personalized, but their degree of temporal variability is also a personalized feature.

scholarly journals Local Environmental Factors Drive Divergent Grassland Soil Bacterial Communities in the Western Swiss Alps

2016 ◽  
Vol 82 (21) ◽  
pp. 6303-6316 ◽  
Author(s):  
Erika Yashiro ◽  
Eric Pinto-Figueroa ◽  
Aline Buri ◽  
Jorge E. Spangenberg ◽  
Thierry Adatte ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Water Content ◽  
Bacterial Diversity ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Swiss Alps ◽  
Content Type ◽  
Soil Bacterial ◽  
Western Swiss Alps

ABSTRACTMountain ecosystems are characterized by a diverse range of climatic and topographic conditions over short distances and are known to shelter a high biodiversity. Despite important progress, still little is known on bacterial diversity in mountain areas. Here, we investigated soil bacterial biogeography at more than 100 sampling sites randomly stratified across a 700-km2area with 2,200-m elevation gradient in the western Swiss Alps. Bacterial grassland communities were highly diverse, with 12,741 total operational taxonomic units (OTUs) across 100 sites and an average of 2,918 OTUs per site. Bacterial community structure was correlated with local climatic, topographic, and soil physicochemical parameters with high statistical significance. We found pH (correlated with % CaO and % mineral carbon), hydrogen index (correlated with bulk gravimetric water content), and annual average number of frost days during the growing season to be among the groups of the most important environmental drivers of bacterial community structure. In contrast, bacterial community structure was only weakly stratified as a function of elevation. Contrasting patterns were discovered for individual bacterial taxa.Acidobacteriaresponded both positively and negatively to pH extremes. Various families within theBacteroidetesresponded to available phosphorus levels. Different verrucomicrobial groups responded to electrical conductivity, total organic carbon, water content, and mineral carbon contents. Alpine grassland bacterial communities are thus highly diverse, which is likely due to the large variety of different environmental conditions. These results shed new light on the biodiversity of mountain ecosystems, which were already identified as potentially fragile to anthropogenic influences and climate change.IMPORTANCEThis article addresses the question of how microbial communities in alpine regions are dependent on local climatic and soil physicochemical variables. We benefit from a unique 700-km2study region in the western Swiss Alps region, which has been exhaustively studied for macro-organismal and fungal ecology, and for topoclimatic modeling of future ecological trends, but without taking into account soil bacterial diversity. Here, we present an in-depth biogeographical characterization of the bacterial community diversity in this alpine region across 100 randomly stratified sites, using 56 environmental variables. Our exhaustive sampling ensured the detection of ecological trends with high statistical robustness. Our data both confirm previously observed general trends and show many new detailed trends for a wide range of bacterial taxonomic groups and environmental parameters.

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