scholarly journals Temporal dynamics in the free-living bacterial community composition in the coastal North Sea

2012 ◽  
Vol 83 (2) ◽  
pp. 413-424 ◽  
Author(s):  
Eva Sintes ◽  
Harry Witte ◽  
Karen Stodderegger ◽  
Paul Steiner ◽  
Gerhard J. Herndl
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
North Sea ◽  
Temporal Dynamics ◽  
Bacterial Community Composition ◽  
Free Living

scholarly journals Temporal Dynamics of South End Tidal Creek (Sapelo Island, Georgia) Bacterial Communities

2008 ◽  
Vol 75 (4) ◽  
pp. 1058-1064 ◽  
Author(s):  
Emily Kara ◽  
Ashley Shade
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Community Dynamics ◽  
Tidal Creek ◽  
Temporal Dynamics ◽  
Bacterial Community Composition ◽  
High Tide ◽  
Cycle Period ◽  
Sapelo Island ◽  
End Tidal

ABSTRACT Bacterial community dynamics in South End tidal creek, Sapelo Island, GA, were studied over a 74-h, five-tidal-cycle period. Observations were made hourly for the first consecutive 24 hours, every 3 hours on the second day, and every 6 hours on the third day. Tide most strongly influenced bacterial community composition (high-tide versus low-tide community analysis of similarities, R = 0.41, P < 0.03). Dissolved oxygen concentration and conductivity were important proximate drivers. However, after accounting for tide and environmental variables colinear with tide, cumulative time became more important in describing community variation. In-stream physical processes, including particulate suspension and sedimentation, may explain tide-associated trends in the bacterial community composition observed.

scholarly journals Colonization in the Photic Zone and Subsequent Changes during Sinking Determine Bacterial Community Composition in Marine Snow

2014 ◽  
Vol 81 (4) ◽  
pp. 1463-1471 ◽  
Author(s):  
Stefan Thiele ◽  
Bernhard M. Fuchs ◽  
Rudolf Amann ◽  
Morten H. Iversen
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Marine Snow ◽  
Free Living ◽  
Fluorescence Maximum

ABSTRACTDue to sampling difficulties, little is known about microbial communities associated with sinking marine snow in the twilight zone. A drifting sediment trap was equipped with a viscous cryogel and deployed to collect intact marine snow from depths of 100 and 400 m off Cape Blanc (Mauritania). Marine snow aggregates were fixed and washedin situto prevent changes in microbial community composition and to enable subsequent analysis using catalyzed reporter deposition fluorescencein situhybridization (CARD-FISH). The attached microbial communities collected at 100 m were similar to the free-living community at the depth of the fluorescence maximum (20 m) but different from those at other depths (150, 400, 550, and 700 m). Therefore, the attached microbial community seemed to be “inherited” from that at the fluorescence maximum. The attached microbial community structure at 400 m differed from that of the attached community at 100 m and from that of any free-living community at the tested depths, except that collected near the sediment at 700 m. The differences between the particle-associated communities at 400 m and 100 m appeared to be due to internal changes in the attached microbial community rather thande novocolonization, detachment, or grazing during the sinking of marine snow. The new sampling method presented here will facilitate future investigations into the mechanisms that shape the bacterial community within sinking marine snow, leading to better understanding of the mechanisms which regulate biogeochemical cycling of settling organic matter.

scholarly journals Environmental Drivers of Free-Living vs. Particle-Attached Bacterial Community Composition in the Mauritania Upwelling System

2018 ◽  
Vol 9 ◽  
Author(s):  
Jennifer Bachmann ◽  
Tabea Heimbach ◽  
Christiane Hassenrück ◽  
Germán A. Kopprio ◽  
Morten Hvitfeldt Iversen ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Environmental Drivers ◽  
Free Living ◽  
Upwelling System

scholarly journals Impacts of Extreme Weather Events on Bacterial Community Composition of a Temperate Humic Lake

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2757
Author(s):  
Alexa Hoke ◽  
Jason Woodhouse ◽  
Luca Zoccarato ◽  
Valerie McCarthy ◽  
Elvira de Eyto ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Communities ◽  
Bacterial Community Composition ◽  
Critical Role ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Free Living ◽  
Drought Period ◽  
Weather Events

Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events.

scholarly journals Increasing addition of autochthonous to allochthonous carbon in nutrient-rich aquatic systems stimulates carbon consumption but does not alter bacterial community composition

2013 ◽  
Vol 10 (8) ◽  
pp. 14261-14300 ◽  
Author(s):  
K. Attermeyer ◽  
T. Hornick ◽  
Z. E. Kayler ◽  
A. Bahr ◽  
E. Zwirnmann ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Temporal Dynamics ◽  
Heterotrophic Bacteria ◽  
Dissolved Inorganic Carbon ◽  
Bacterial Community Composition ◽  
Trophic Levels ◽  
Aquatic Systems ◽  
Chemical Quality ◽  
Carbon Consumption

Abstract. Dissolved organic carbon (DOC) concentrations – mainly of terrestrial origin – are increasing worldwide in inland waters. The biodegradability of the DOC varies depending on quantity and chemical quality. Heterotrophic bacteria are the main consumers of DOC and thus determine DOC temporal dynamics and availability for higher trophic levels. It is therefore crucial to understand the processes controlling the bacterial turnover of additional allochthonous and autochthonous DOC in aquatic systems. Our aim was to study bacterial carbon (C) turnover with respect to DOC quantity and chemical quality using both allochthonous and autochthonous DOC sources. We incubated a natural bacterial community with allochthonous C (13C-labeled beech leachate) and increased concentrations and pulses (intermittent occurrence of organic matter input) of autochthonous C (algae lysate). We then determined bacterial carbon consumption, activities, and community composition together with the carbon flow through bacteria using stable C isotopes. The chemical analysis of single sources revealed differences in aromaticity and fractions of low and high molecular weight substances (LMWS and HMWS, respectively) between allochthonous and autochthonous C sources. In parallel to these differences in chemical composition, we observed a higher availability of allochthonous C as evidenced by increased DOC consumption and bacterial growth efficiencies (BGE) when solely allochthonous C was provided. In treatments with mixed sources, rising concentrations of added autochthonous DOC resulted in a further, significant increase in bacterial DOC consumption from 52 to 68% when nutrients were not limiting. This rise was accompanied by a decrease in the humic substances (HS) fraction and an increase in bacterial biomass. Stable C isotope analyses of phospholipid fatty acids (PLFA) and respired dissolved inorganic carbon (DIC) supported a preferential assimilation of autochthonous C and respiration of the allochthonous C. Changes in DOC concentration and consumption in mixed treatments did not affect bacterial community composition (BCC), but BCC differed in single vs. mixed incubations. Our study highlights that DOC quantity affects bacterial C consumption but not BCC in nutrient-rich aquatic systems. BCC shifted when a mixture of allochthonous and autochthonous C was provided simultaneously to the bacterial community. Our results indicate that chemical quality rather than source of DOC per se (allochthonous vs. autochthonous) determines bacterial DOC turnover.

scholarly journals Complexity of Bacterial Communities in a River-Floodplain System (Danube, Austria)

2005 ◽  
Vol 71 (2) ◽  
pp. 609-620 ◽  
Author(s):  
Katharina Besemer ◽  
Markus M. Moeseneder ◽  
Jesus M. Arrieta ◽  
Gerhard J. Herndl ◽  
Peter Peduzzi
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Temporal Dynamics ◽  
Bacterial Community Composition ◽  
Inorganic Nutrients ◽  
Danube River ◽  
Polymorphism Analysis ◽  
Free Living ◽  
River Floodplain

ABSTRACT Natural floodplains play an essential role in the processing and decomposition of organic matter and in the self-purification ability of rivers, largely due to the activity of bacteria. Knowledge about the composition of bacterial communities and its impact on organic-matter cycling is crucial for the understanding of ecological processes in river-floodplain systems. Particle-associated and free-living bacterial assemblages from the Danube River and various floodplain pools with different hydrological characteristics were investigated using terminal restriction fragment length polymorphism analysis. The particle-associated bacterial community exhibited a higher number of operational taxonomic units (OTUs) and was more heterogeneous in time and space than the free-living community. The temporal dynamics of the community structure were generally higher in isolated floodplain pools. The community structures of the river and the various floodplain pools, as well as those of the particle-associated and free-living bacteria, differed significantly. The compositional dynamics of the planktonic bacterial communities were related to changes in the algal biomass, temperature, and concentrations of organic and inorganic nutrients. The OTU richness of the free-living community was correlated with the concentration and origin of organic matter and the concentration of inorganic nutrients, while no correlation with the OTU richness of the particle-associated assemblage was found. Our results demonstrate the importance of the river-floodplain interactions and the influence of damming and regulation on the bacterial-community composition.

scholarly journals Enhanced bacterial decomposition with increasing addition of autochthonous to allochthonous carbon without any effect on bacterial community composition

2014 ◽  
Vol 11 (6) ◽  
pp. 1479-1489 ◽  
Author(s):  
K. Attermeyer ◽  
T. Hornick ◽  
Z. E. Kayler ◽  
A. Bahr ◽  
E. Zwirnmann ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Temporal Dynamics ◽  
Heterotrophic Bacteria ◽  
Bacterial Community Composition ◽  
Bacterial Biomass ◽  
Trophic Levels ◽  
Bacterial Growth Efficiency ◽  
Chemical Quality ◽  
Bacterial C

Abstract. Dissolved organic carbon (DOC) concentrations – mainly of terrestrial origin – are increasing worldwide in inland waters. Heterotrophic bacteria are the main consumers of DOC and thus determine DOC temporal dynamics and availability for higher trophic levels. Our aim was to study bacterial carbon (C) turnover with respect to DOC quantity and chemical quality using both allochthonous and autochthonous DOC sources. We incubated a natural bacterial community with allochthonous C (13C-labeled beech leachate) and increased concentrations and pulses (intermittent occurrence of organic matter input) of autochthonous C (phytoplankton lysate). We then determined bacterial C consumption, activities, and community composition together with the C flow through bacteria using stable C isotopes. The chemical analysis of single sources revealed differences in aromaticity and low- and high-molecular-weight substance fractions (LMWS and HMWS, respectively) between allochthonous and autochthonous C sources. Both DOC sources (allochthonous and autochthonous DOC) were metabolized at a high bacterial growth efficiency (BGE) around 50%. In treatments with mixed sources, rising concentrations of added autochthonous DOC resulted in a further, significant increase in bacterial DOC consumption of up to 68% when nutrients were not limiting. This rise was accompanied by a decrease in the humic substance (HS) fraction and an increase in bacterial biomass. Changes in DOC concentration and consumption in mixed treatments did not affect bacterial community composition (BCC), but BCC differed in single vs. mixed incubations. Our study highlights that DOC quantity affects bacterial C consumption but not BCC in nutrient-rich aquatic systems. BCC shifted when a mixture of allochthonous and autochthonous C was provided simultaneously to the bacterial community. Our results indicate that chemical quality rather than source of DOC per se (allochthonous vs. autochthonous) determines bacterial DOC turnover.

scholarly journals Abiotic environmental factors override phytoplankton succession in shaping both free-living and attached bacterial communities in a highland lake

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Huan Wang ◽  
Rong Zhu ◽  
Xiaolin Zhang ◽  
Yun Li ◽  
Leyi Ni ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Bacterial Community ◽  
Species Composition ◽  
Community Composition ◽  
Bacterial Communities ◽  
Phytoplankton Community ◽  
Bacterial Community Composition ◽  
Free Living ◽  
The Impact ◽  
Abiotic Environmental Factors

Abstract Bacterial communities are an important part of biological diversity and biogeochemical cycling in aquatic ecosystems. In this study, the relationship amongst the phytoplankton species composition and abiotic environmental factors on seasonal changes in the community composition of free-living and attached bacteria in Lake Erhai were studied. Using Illumina high-throughput sequencing, we found that the impact of environmental factors on both the free-living and attached bacterial community composition was greater than that of the phytoplankton community, amongst which total phosphorus, Secchi disk, water temperature, dissolved oxygen and conductivity strongly influenced bacterial community composition. Microcystis blooms associated with subdominant Psephonema occurred during the summer and autumn, and Fragilaria, Melosira and Mougeotia were found at high densities in the other seasons. Only small numbers of algal species-specific bacteria, including Xanthomonadaceae (Proteobacteria) and Alcaligenaceae (Betaproteobacteria), were tightly coupled to Microcystis and Psephonema during Microcystis blooms. Redundancy analysis showed that although the composition of the bacterial communities was controlled by species composition mediated by changes in phytoplankton communities and abiotic environmental factors, the impact of the abiotic environment on both free-living and attached bacterial community compositions were greater than the impact of the phytoplankton community. These results suggest that the species composition of both free-living and attached bacterial communities are affected by abiotic environmental factors, even when under strong control by biotic factors, particularly dominant genera of Microcystis and Psephonema during algal blooms.

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