scholarly journals Use of organic exudates from two polar diatoms by bacterial isolates from the Arctic Ocean

2020 ◽  
Vol 378 (2181) ◽  
pp. 20190356 ◽  
Author(s):  
Lucas Tisserand ◽  
Laëtitia Dadaglio ◽  
Laurent Intertaglia ◽  
Philippe Catala ◽  
Christos Panagiotopoulos ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Model Systems ◽  
The Arctic ◽  
Bacterial Strains ◽  
Biological Communities ◽  
Polar Diatoms

Global warming affects primary producers in the Arctic, with potential consequences for the bacterial community composition through the consumption of microalgae-derived dissolved organic matter (DOM). To determine the degree of specificity in the use of an exudate by bacterial taxa, we used simple microalgae–bacteria model systems. We isolated 92 bacterial strains from the sea ice bottom and the water column in spring–summer in the Baffin Bay (Arctic Ocean). The isolates were grouped into 42 species belonging to Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. Forty strains were tested for their capacity to grow on the exudate from two Arctic diatoms . Most of the strains tested (78%) were able to grow on the exudate from the pelagic diatom Chaetoceros neogracilis , and 33% were able to use the exudate from the sea ice diatom Fragilariopsis cylindrus . 17.5% of the strains were not able to grow with any exudate, while 27.5% of the strains were able to use both types of exudates. All strains belonging to Flavobacteriia ( n  = 10) were able to use the DOM provided by C. neogracilis , and this exudate sustained a growth capacity of up to 100 times higher than diluted Marine Broth medium, of two Pseudomonas sp. strains and one Sulfitobacter strain. The variable bioavailability of exudates to bacterial strains highlights the potential role of microalgae in shaping the bacterial community composition. This article is part of the theme issue ‘The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

scholarly journals Effects of Vertical Water Mass Segregation on Bacterial Community Structure in the Beaufort Sea

2019 ◽  
Vol 7 (10) ◽  
pp. 385
Author(s):  
Yunyun Fu ◽  
Richard B. Rivkin ◽  
Andrew S. Lang
Keyword(s):  
Bacterial Community ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Community Composition ◽  
Bacterial Communities ◽  
Water Mass ◽  
Beaufort Sea ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Mass Segregation

The Arctic Ocean is one of the least well-studied marine microbial ecosystems. Its low-temperature and low-salinity conditions are expected to result in distinct bacterial communities, in comparison to lower latitude oceans. However, this is an ocean currently in flux, with climate change exerting pronounced effects on sea-ice coverage and freshwater inputs. How such changes will affect this ecosystem are poorly constrained. In this study, we characterized the bacterial community compositions at different depths in both coastal, freshwater-influenced, and pelagic, sea-ice-covered locations in the Beaufort Sea in the western Canadian Arctic Ocean. The environmental factors controlling the bacterial community composition and diversity were investigated. Alphaproteobacteria dominated the bacterial communities in samples from all depths and stations. The Pelagibacterales and Rhodobacterales groups were the predominant taxonomic representatives within the Alphaproteobacteria. Bacterial communities in coastal and offshore samples differed significantly, and vertical water mass segregation was the controlling factor of community composition among the offshore samples, regardless of the taxonomic level considered. These data provide an important baseline view of the bacterial community in this ocean system that will be of value for future studies investigating possible changes in the Arctic Ocean in response to global change and/or anthropogenic disturbance.

Sea ice biological communities and nutrient dynamics in the Canada Basin of the Arctic Ocean

2002 ◽  
Vol 49 (9) ◽  
pp. 1623-1649 ◽  
Author(s):  
Igor A Melnikov ◽  
Elena G Kolosova ◽  
Harold E Welch ◽  
Ludmila S Zhitina
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Nutrient Dynamics ◽  
Canada Basin ◽  
The Arctic ◽  
Biological Communities ◽  
The Arctic Ocean

scholarly journals Latitudinal Distributions and Controls of Bacterial Community Composition during the Summer of 2017 in Western Arctic Surface Waters (from the Bering Strait to the Chukchi Borderland)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiyoung Lee ◽  
Sung-Ho Kang ◽  
Eun Jin Yang ◽  
Alison M. Macdonald ◽  
Hyoung Min Joo ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Arctic Ocean ◽  
Community Composition ◽  
Surface Waters ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Bering Strait ◽  
Western Arctic ◽  
Chukchi Borderland

AbstractThe western Arctic Ocean is experiencing some of the most rapid environmental changes in the Arctic. However, little is known about the microbial community response to these changes. Employing observations from the summer of 2017, this study investigated latitudinal variations in bacterial community composition in surface waters between the Bering Strait and Chukchi Borderland and the factors driving the changes. Results indicate three distinctive communities. Southern Chukchi bacterial communities are associated with nutrient rich conditions, including genera such as Sulfitobacter, whereas the northern Chukchi bacterial community is dominated by SAR clades, Flavobacterium, Paraglaciecola, and Polaribacter genera associated with low nutrients and sea ice conditions. The frontal region, located on the boundary between the southern and northern Chukchi, is a transition zone with intermediate physical and biogeochemical properties; however, bacterial communities differed markedly from those found to the north and south. In the transition zone, Sphingomonas, with as yet undetermined ecological characteristics, are relatively abundant. Latitudinal distributions in bacterial community composition are mainly attributed to physical and biogeochemical characteristics, suggesting that these communities are susceptible to Arctic environmental changes. These findings provide a foundation to improve understanding of bacterial community variations in response to a rapidly changing Arctic Ocean.

scholarly journals How Microbial Food Web Interactions Shape the Arctic Ocean Bacterial Community Revealed by Size Fractionation Experiments

2021 ◽  
Vol 9 (11) ◽  
pp. 2378
Author(s):  
Oliver Müller ◽  
Lena Seuthe ◽  
Bernadette Pree ◽  
Gunnar Bratbak ◽  
Aud Larsen ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Food Web ◽  
Community Composition ◽  
Seasonal Changes ◽  
Bacterial Community Composition ◽  
Trophic Levels ◽  
The Arctic ◽  
Microbial Food Web ◽  
Small Scale ◽  
Size Fractionation

In the Arctic, seasonal changes are substantial, and as a result, the marine bacterial community composition and functions differ greatly between the dark winter and light-intensive summer. While light availability is, overall, the external driver of the seasonal changes, several internal biological interactions structure the bacterial community during shorter timescales. These include specific phytoplankton–bacteria associations, viral infections and other top-down controls. Here, we uncover these microbial interactions and their effects on the bacterial community composition during a full annual cycle by manipulating the microbial food web using size fractionation. The most profound community changes were detected during the spring, with ‘mutualistic phytoplankton’—Gammaproteobacteria interactions dominating in the pre-bloom phase and ‘substrate-dependent phytoplankton’—Flavobacteria interactions during blooming conditions. Bacterivores had an overall limited effect on the bacterial community composition most of the year. However, in the late summer, grazing was the main factor shaping the community composition and transferring carbon to higher trophic levels. Identifying these small-scale interactions improves our understanding of the Arctic marine microbial food web and its dynamics.

scholarly journals Bacterial community composition and diversity of two different forms of an organic residue of bioenergy crop

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6768
Author(s):  
Matheus A.P. Cipriano ◽  
Afnan K.A. Suleiman ◽  
Adriana P.D. da Silveira ◽  
Janaína B. do Carmo ◽  
Eiko E. Kuramae
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
16S Rrna ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Nitrous Oxide Emissions ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Microbial Composition

The use of residue of sugarcane ethanol industry named vinasse in fertirrigation is an established and widespread practice in Brazil. Both non-concentrated vinasse (NCV) and concentrated vinasse (CV) are used in fertirrigation, particularly to replace the potassium fertilizer. Although studies on the chemical and organic composition of vinasse and their impact on nitrous oxide emissions when applied in soil have been carried out, no studies have evaluated the microbial community composition and diversity in different forms of vinasse. We assessed the bacterial community composition of NCV and CV by non-culturable and culturable approaches. The non-culturable bacterial community was assessed by next generation sequencing of the 16S rRNA gene and culturable community by isolation of bacterial strains and molecular and biochemical characterization. Additionally, we assessed in the bacterial strains the presence of genes of nitrogen cycle nitrification and denitrification pathways. The microbial community based on16S rRNAsequences of NCV was overrepresented by Bacilli and Negativicutes while CV was mainly represented by Bacilli class. The isolated strains from the two types of vinasse belong to class Bacilli, similar toLysinibacillus, encode fornirKgene related to denitrification pathway. This study highlights the bacterial microbial composition particularly in CV what residue is currently recycled and recommended as a sustainable practice in sugarcane cultivation in the tropics.

scholarly journals Collection of Environmental Variables and Bacterial Community Compositions in Marian Cove, Antarctica, during Summer 2018

Data ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 27
Author(s):  
Hyo-Ryeon Kim ◽  
Jae-Hyun Lim ◽  
Ju-Hyoung Kim ◽  
Il-Nam Kim
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Marine Bacteria ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Composition Data ◽  
Decomposition Of Organic Matter ◽  
Class Level ◽  
Earth’S Climate

Marine bacteria, which are known as key drivers for marine biogeochemical cycles and Earth’s climate system, are mainly responsible for the decomposition of organic matter and production of climate-relevant gases (i.e., CO₂, N₂O, and CH₄). However, research is still required to fully understand the correlation between environmental variables and bacteria community composition. Marine bacteria living in the Marian Cove, where the inflow of freshwater has been rapidly increasing due to substantial glacial retreat, must be undergoing significant environmental changes. During the summer of 2018, we conducted a hydrographic survey to collect environmental variables and bacterial community composition data at three different layers (i.e., the seawater surface, middle, and bottom layers) from 15 stations. Of all the bacterial data, 17 different phylum level bacteria and 21 different class level bacteria were found and Proteobacteria occupy 50.3% at phylum level following Bacteroidetes. Gammaproteobacteria and Alphaproteobacteria, which belong to Proteobacteria, are the highest proportion at the class level. Gammaproteobacteria showed the highest relative abundance in all three seawater layers. The collection of environmental variables and bacterial composition data contributes to improving our understanding of the significant relationships between marine Antarctic regions and marine bacteria that lives in the Antarctic.

scholarly journals Artificial neural network analysis of microbial diversity in the central and southern Adriatic Sea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Danijela Šantić ◽  
Kasia Piwosz ◽  
Frano Matić ◽  
Ana Vrdoljak Tomaš ◽  
Jasna Arapov ◽  
...  
Keyword(s):  
Neural Network ◽  
Network Analysis ◽  
Bacterial Community ◽  
Microbial Diversity ◽  
Community Composition ◽  
Adriatic Sea ◽  
Bacterial Community Composition ◽  
Environmental Data ◽  
Large Contribution ◽  
Neural Network Analysis

AbstractBacteria are an active and diverse component of pelagic communities. The identification of main factors governing microbial diversity and spatial distribution requires advanced mathematical analyses. Here, the bacterial community composition was analysed, along with a depth profile, in the open Adriatic Sea using amplicon sequencing of bacterial 16S rRNA and the Neural gas algorithm. The performed analysis classified the sample into four best matching units representing heterogenic patterns of the bacterial community composition. The observed parameters were more differentiated by depth than by area, with temperature and identified salinity as important environmental variables. The highest diversity was observed at the deep chlorophyll maximum, while bacterial abundance and production peaked in the upper layers. The most of the identified genera belonged to Proteobacteria, with uncultured AEGEAN-169 and SAR116 lineages being dominant Alphaproteobacteria, and OM60 (NOR5) and SAR86 being dominant Gammaproteobacteria. Marine Synechococcus and Cyanobium-related species were predominant in the shallow layer, while Prochlorococcus MIT 9313 formed a higher portion below 50 m depth. Bacteroidota were represented mostly by uncultured lineages (NS4, NS5 and NS9 marine lineages). In contrast, Actinobacteriota were dominated by a candidatus genus Ca. Actinomarina. A large contribution of Nitrospinae was evident at the deepest investigated layer. Our results document that neural network analysis of environmental data may provide a novel insight into factors affecting picoplankton in the open sea environment.

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