scholarly journals Temporal dynamics of Bacteria, Archaea and protists in equatorial coastal waters

2019 ◽  
Author(s):  
Caroline Chénard ◽  
Winona Wijaya ◽  
Daniel Vaulot ◽  
Adriana Lopes dos Santos ◽  
Patrick Martin ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Coastal Waters ◽  
Seasonal Variability ◽  
Temporal Dynamics ◽  
Anthropogenic Activities ◽  
Seasonal Pattern ◽  
Rrna Gene ◽  
Marine Microbe ◽  
Johor Strait ◽  
Singapore Strait

ABSTRACTSingapore, an equatorial island in South East Asia, is influenced by a bi-annual reversal of wind directions which defines two monsoon seasons. We characterized the dynamics of the microbial communities of Singapore coastal waters by collecting monthly samples between February 2017 and July 2018 at four sites located across two straits with different trophic status, and sequencing the V6-V8 region of the small sub-unit ribosomal RNA gene (rRNA gene) of Bacteria, Archaea, and Eukaryota. Johor Strait, which is subjected to wider environmental fluctuations from anthropogenic activities, presented a higher abundance of copiotrophic microbes, including Cellvibrionales and Rhodobacterales. The mesotrophic Singapore Strait, where the seasonal variability is caused by changes in the oceanographic conditions, harboured a higher proportion of typically marine microbe groups such as Synechococcales, Nitrosupumilales, SAR11, SAR86, Marine Group II Archaea and Radiolaria. In addition, we observed seasonal variability of the microbial communities in the Singapore Strait, which was possibly influenced by the alternating monsoon regime, while no seasonal pattern was detected in the Johor Strait.

scholarly journals Temporal and spatial dynamics of Bacteria, Archaea and protists in equatorial coastal waters

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Caroline Chénard ◽  
Winona Wijaya ◽  
Daniel Vaulot ◽  
Adriana Lopes dos Santos ◽  
Patrick Martin ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Coastal Waters ◽  
Seasonal Variability ◽  
Anthropogenic Activities ◽  
Seasonal Pattern ◽  
Spatial Dynamics ◽  
Rrna Gene ◽  
Marine Microbe ◽  
Johor Strait ◽  
Singapore Strait

Abstract Singapore, an equatorial island in South East Asia, is influenced by a bi-annual reversal of wind directions which defines two monsoon seasons. We characterized the dynamics of the microbial communities of Singapore coastal waters by collecting monthly samples between February 2017 and July 2018 at four sites located across two straits with different trophic status, and sequencing the V6-V8 region of the small sub-unit ribosomal RNA gene (rRNA gene) of Bacteria, Archaea, and Eukaryota. Johor Strait, which is subjected to wider environmental fluctuations from anthropogenic activities, presented a higher abundance of copiotrophic microbes, including Cellvibrionales and Rhodobacterales. The mesotrophic Singapore Strait, where the seasonal variability is caused by changes in the oceanographic conditions, harboured a higher proportion of typically marine microbe groups such as Synechococcales, Nitrosupumilales, SAR11, SAR86, Marine Group II Archaea and Radiolaria. In addition, we observed seasonal variability of the microbial communities in the Singapore Strait, which was possibly influenced by the alternating monsoon regime, while no seasonal pattern was detected in the Johor Strait.

scholarly journals Spatial and Temporal Distribution of Soil Microbial Properties in Two Shrub Intercrop Systems of the Sahel

2021 ◽  
Vol 5 ◽  
Author(s):  
Sire Diedhiou-Sall ◽  
Komi B. Assigbetsee ◽  
Aminata N. Badiane ◽  
Ibrahima Diedhiou ◽  
M. Khouma ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Enzyme Activities ◽  
Temporal Dynamics ◽  
Dry Season ◽  
Hydraulic Lift ◽  
Annual Rainfall ◽  
Rrna Gene ◽  
28S Rrna ◽  
Microbial Composition ◽  
Row Crops

The Sahel is an ecologically vulnerable region where increasing populations with a concurrent increase in agricultural intensity has degraded soils. Agroforestry offers an approach to remediate these landscapes. A largely unrecognized agroforestry resource in the Sahel are the native shrubs, Piliostigma reticulatum, and Guiera senegalensis that to varying degrees already coexist with row crops. These shrubs improve soil quality, redistribute water from the deep soil to the surface (hydraulic lift), and can improve crop growth. However, little information is available on whether these shrubs affect spatial and temporal dynamics of microbial communities. Therefore, the objective of this study was to determine microbial composition and activity in the wet and dry seasons of soil in the: shrub rhizosphere (RhizS), inter-root zone (IntrS), and outside the influence of shrub soil (OutS) for both G. senegalensis and P. reticulatum in Senegal. A 3 × 2 factorial field experiment was imposed at two locations (490 and 700 mm annual rainfall with G. senegalensis and P. reticulatum, respectively), that had the soil sampling treatments of three locations (RhizS, IntrS, and OutS) and two seasons (wet and dry). Soils were analyzed for: microbial diversity (DGGE with bacterial 16S or fungal 28S rRNA gene sequences phospholipids fatty acid, PLFA); enzyme activities; microbial biomass carbon (MBC); and nitrogen (N) mineralization potential. For the DGGE profiling, the bacterial community responded more to the rhizosphere effect, whereas, the fungal community was more sensitive to season. PLFA, MBC, enzyme activities and inorganic N were significantly higher in both seasons for the RhizS. The presence of shrubs maintained rhizosphere microbial communities and activity during the dry season. This represents a paradigm shift for semi-arid environments where logically it would be expected to have no microbial activity in the extended dry season. In contrast this study has shown this is not the case that rather the presence of shrub roots maintained the microbial community in the dry season most likely due to hydraulic lift and root exudates. This has implications when these shrubs are in cropped fields in that decomposition and mineralization of nutrients can proceed in the dry season. Thus, enabling accumulation of plant available nutrients during the dry season for uptake by crops in the rainy season.

scholarly journals Microbial diversity of the glass sponge Vazella pourtalesii in response to anthropogenic activities

2020 ◽  
Vol 21 (6) ◽  
pp. 1001-1010 ◽  
Author(s):  
Kathrin Busch ◽  
Lindsay Beazley ◽  
Ellen Kenchington ◽  
Frederick Whoriskey ◽  
Beate M. Slaby ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Microbial Communities ◽  
Anthropogenic Impacts ◽  
Anthropogenic Activities ◽  
Amplicon Sequencing ◽  
Habitat Destruction ◽  
Artificial Substrates ◽  
Rrna Gene ◽  
Anthropogenic Pressures ◽  
Glass Sponge

Abstract Establishment of adequate conservation areas represents a challenging but crucial task in the conservation of genetic diversity and biological variability. Anthropogenic pressures on marine ecosystems and organisms are steadily increasing. Whether and to what extent these pressures influence marine genetic biodiversity is only starting to be revealed. Using 16S rRNA gene amplicon sequencing, we analysed the microbial community structure of 33 individuals of the habitat-forming glass sponge Vazella pourtalesii, as well as reference seawater, sediment, and biofilm samples. We assessed how two anthropogenic impacts, i.e. habitat destruction by trawling and artificial substrate provision (moorings made of composite plastic), correspond with in situ V. pourtalesii microbiome variability. In addition, we evaluated the role of two bottom fishery closures in preserving sponge-associated microbial diversity on the Scotian Shelf, Canada. Our results illustrate that V. pourtalesii sponges collected from protected sites within fishery closures contained distinct and taxonomically largely novel microbial communities. At the trawled site we recorded significant quantitative differences in distinct microbial phyla, such as a reduction in Nitrospinae in the four sponges from this site and the environmental references. Individuals of V. pourtalesii growing on the mooring were significantly enriched in Bacteroidetes, Verrucomicrobia and Cyanobacteria in comparison to sponge individuals growing on the natural seabed. Due to a concomitant enrichment of these taxa in the mooring biofilm, we propose that biofilms on artificial substrates may ‘prime’ sponge-associated microbial communities when small sponges settle on such substrates. These observations likely have relevant management implications when considering the increase of artificial substrates in the marine environment, e.g., marine litter, off-shore wind parks, and petroleum platforms.

scholarly journals Microbial diversity of the glass sponge Vazella pourtalesii in response to anthropogenic activities

2020 ◽  
Author(s):  
Kathrin Busch ◽  
Lindsay Beazley ◽  
Ellen Kenchington ◽  
Frederick Whoriskey ◽  
Beate Slaby ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Microbial Communities ◽  
Anthropogenic Impacts ◽  
Anthropogenic Activities ◽  
Amplicon Sequencing ◽  
Habitat Destruction ◽  
Artificial Substrates ◽  
Rrna Gene ◽  
Anthropogenic Pressures ◽  
Glass Sponge

ABSTRACTEstablishment of adequate conservation areas represents a challenging but crucial task in the conservation of genetic diversity and biological variability. Anthropogenic pressures on marine ecosystems and organisms are steadily increasing. Whether and to what extent these pressures influence marine genetic biodiversity is only starting to be revealed. Using 16S rRNA gene amplicon sequencing, we analysed the microbial community structure of 33 individuals of the habitat-forming glass sponge Vazella pourtalesii, as well as reference seawater, sediment, and biofilm samples. We assessed how two anthropogenic impacts, i.e. habitat destruction by trawling and artificial substrate provision (moorings made of composite plastic), correspond with in situ V. pourtalesii microbiome variability. In addition, we evaluated the role of two bottom fishery closures in preserving sponge-associated microbial diversity on the Scotian Shelf, Canada. Our results illustrate that V. pourtalesii sponges collected from pristine sites within fishery closures contained distinct and taxonomically largely novel microbial communities. At the trawled site we recorded significant quantitative differences in distinct microbial phyla, such as a reduction in Nitrospinae in sponges and environmental references. Individuals of V. pourtalesii growing on the mooring were significantly enriched in Bacteroidetes, Verrucomicrobia and Cyanobacteria in comparison to sponge individuals growing on the natural seabed. Due to a concomitant enrichment of these taxa in the mooring biofilm, we propose that biofilms on artificial substrates may ‘prime’ sponge-associated microbial communities when small sponges settle on such substrates. These observations likely have relevant management implications when considering the increase of artificial substrates in the marine environment, e.g., marine litter, off-shore wind parks, and petroleum platforms.

scholarly journals Biodiversity of microbial communities on some species in the class Gastropoda common in coastal waters in Central Vietnam

2019 ◽  
Vol 27 (1) ◽  
pp. 29-38
Author(s):  
Thanh Binh Chu ◽  
Thi Thu Hong Do ◽  
Xuan Thinh Le ◽  
Cao Cuong Ngo ◽  
Thi Thu Huyen Pham ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Communities ◽  
Large Class ◽  
Coastal Waters ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Yeast Strains ◽  
Central Vietnam

Gastropoda is a large class in coastal waters in Central Vietnam. The interaction between microorganisms and Gastropoda mainly consists of symbiotic and parasitic relationships. In this study, biodiversity of microbial communities on some species of Gastropoda is evaluated, thereby predicting their interaction. From 12 samples of Gastropoda including 3 species: Trochus maculatus , Cypraea eglantica , Chicoreus bruneus , 101 microorganism strains including 79 bacterial strains (78.2%), 18 yeast strains (17.8%) and 4 actinomycetes strains (4.0%) were isolated. There were 15 strains (including 8 yeast strains, 5 bacterial strains and 2 actinomycetes strains) selected to identify based on sequence analysis of the D1/D2 region (yeast) and 16S rRNA gene (bacteria and actinomycetes). Based on the identification results, it is possible to predict the nutritional relationship between microorganisms and species of Gastropoda.

scholarly journals Dynamics and Heterogeneity of Microbial Communities in Urban Water Environments

2020 ◽  
Author(s):  
Yanqing Lian ◽  
Lisha Zhen ◽  
Xi Chen ◽  
Yang Li ◽  
Xiaona Li
Keyword(s):  
Microbial Communities ◽  
Urban Areas ◽  
Pathogenic Bacteria ◽  
Temporal Dynamics ◽  
Statistical Analyses ◽  
Polluted Water ◽  
Outer Side ◽  
Rrna Gene ◽  
The City ◽  
The 16S Rrna Gene

Abstract Water samples for the 16S rRNA gene and water quality analyses were collected from around 155 kilometers of river segments surrounding the urban areas in Xi’an of China. Multiple statistical analyses showed the temporal dynamics of microbial communities and heterogeneity in their spatial distributions. The dynamic shifts of microbial communities in the Chan, Ba, and Feng Rivers from the Spring to the Summer seasons were apparent, but little in the Zao River. The heterogeneity of microbial distributions was more due to the influence of hydrologic conditions and various sources of inflows in the rivers. The LEfSe analysis showed the Chan and Zao Rivers, both were more impacted by the sewage effluents, were more differentially abundant with bacteria related to polluted water, but the Ba and Feng Rivers, both on the outer side of the city, were more abundant with microbial communities in soil and freshwater environments in August. Multiple statistical analyses indicated that environmental variables had a significant impact on microbial communities. The GIS-based spatial analysis not only showed heterogeneity of microbial community distributions along the rivers, more importantly, could help identify locations where pathogenic bacteria presented.

scholarly journals Press Disturbance Alters Community Structure and Assembly Mechanisms of Bacterial Taxa and Functional Genes in Mesocosm-Scale Bioreactors

mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Ezequiel Santillan ◽  
Florentin Constancias ◽  
Stefan Wuertz
Keyword(s):  
Community Structure ◽  
Microbial Communities ◽  
Community Assembly ◽  
Temporal Dynamics ◽  
Functional Gene ◽  
Functional Genes ◽  
Rrna Gene ◽  
Α Diversity ◽  
Press Disturbance ◽  
Joint Evaluation

ABSTRACT Press disturbances are of interest in microbial ecology, as they can drive microbial communities to alternative stable states. However, the effect of press disturbances in community assembly mechanisms, particularly with regard to taxa and functional genes at different levels of abundance (i.e., common and rare), remains largely unknown. Here, we tested the effect of a continuous alteration in substrate feeding scheme on the structure, function, and assembly of bacterial communities. Two sets of replicate 5-liter sequencing batch reactors were operated at two different organic carbon loads for a period of 74 days, following 53 days of acclimation after inoculation with sludge from a full-scale treatment plant. Temporal dynamics of community taxonomic and functional gene structure were derived from metagenomics and 16S rRNA gene metabarcoding data. Disturbed reactors exhibited different community function, structure, and assembly compared to undisturbed reactors. Bacterial taxa and functional genes showed dissimilar α-diversity and community assembly patterns. Deterministic assembly mechanisms were generally stronger in disturbed reactors and in common fractions compared to rare ones. Function quickly recovered after the disturbance was removed, but community structure did not. Our results highlight that functional gene data from metagenomics can indicate patterns of community assembly that differ from those obtained from taxon data. This study reveals how a joint evaluation of assembly mechanisms and community structure of bacterial taxa and functional genes as well as ecosystem function can unravel the response of complex microbial systems to a press disturbance. IMPORTANCE Ecosystem management must be viewed in the context of increasing frequencies and magnitudes of various disturbances that occur at different scales. This work provides a glimpse of the changes in assembly mechanisms found in microbial communities exposed to sustained changes in their environment. These mechanisms, deterministic or stochastic, can cause communities to reach a similar or variable composition and function. For a comprehensive view, we use a joint evaluation of temporal dynamics in assembly mechanisms and community structure for both bacterial taxa and their functional genes at different abundance levels, in both disturbed and undisturbed states. We further reverted the disturbance state to contrast recovery of function with community structure. Our findings are relevant, as very few studies have employed such an approach, while there is a need to assess the relative importance of assembly mechanisms for microbial communities across different spatial and temporal scales, environmental gradients, and types of disturbance.

scholarly journals Terrestrial Inputs Shape Coastal Bacterial and Archaeal Communities in a High Arctic Fjord (Isfjorden, Svalbard)

2021 ◽  
Vol 12 ◽  
Author(s):  
Lisa-Marie Delpech ◽  
Tobias R. Vonnahme ◽  
Maeve McGovern ◽  
Rolf Gradinger ◽  
Kim Præbel ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Coastal Waters ◽  
Environmental Gradients ◽  
Late Summer ◽  
High Arctic ◽  
Atlantic Water ◽  
The Arctic ◽  
Rrna Gene ◽  
Terrestrial Runoff ◽  
Terrestrial Inputs

The Arctic is experiencing dramatic changes including increases in precipitation, glacial melt, and permafrost thaw, resulting in increasing freshwater runoff to coastal waters. During the melt season, terrestrial runoff delivers carbon- and nutrient-rich freshwater to Arctic coastal waters, with unknown consequences for the microbial communities that play a key role in determining the cycling and fate of terrestrial matter at the land-ocean interface. To determine the impacts of runoff on coastal microbial (bacteria and archaea) communities, we investigated changes in pelagic microbial community structure between the early (June) and late (August) melt season in 2018 in the Isfjorden system (Svalbard). Amplicon sequences of the 16S rRNA gene were generated from water column, river and sediment samples collected in Isfjorden along fjord transects from shallow river estuaries and glacier fronts to the outer fjord. Community shifts were investigated in relation to environmental gradients, and compared to river and marine sediment microbial communities. We identified strong temporal and spatial reorganizations in the structure and composition of microbial communities during the summer months in relation to environmental conditions. Microbial diversity patterns highlighted a reorganization from rich communities in June toward more even and less rich communities in August. In June, waters enriched in dissolved organic carbon (DOC) provided a niche for copiotrophic taxa including Sulfitobacter and Octadecabacter. In August, lower DOC concentrations and Atlantic water inflow coincided with a shift toward more cosmopolitan taxa usually associated with summer stratified periods (e.g., SAR11 Clade Ia), and prevalent oligotrophic marine clades (OM60, SAR92). Higher riverine inputs of dissolved inorganic nutrients and suspended particulate matter also contributed to spatial reorganizations of communities in August. Sentinel taxa of this late summer fjord environment included taxa from the class Verrucomicrobiae (Roseibacillus, Luteolibacter), potentially indicative of a higher fraction of particle-attached bacteria. This study highlights the ecological relevance of terrestrial runoff for Arctic coastal microbial communities and how its impacts on biogeochemical conditions may make these communities susceptible to climate change.

scholarly journals Metagenomic analysis of soil samples collected from estuarine mangroves of Arabian Sea reveals rich microbiota and high numbers of sulphate reducing bacteria accompanied with methanogen bacteria

2019 ◽  
Author(s):  
Mandar S. Paingankar ◽  
Deepti D. Deobagkar
Keyword(s):  
Microbial Communities ◽  
Arabian Sea ◽  
Anthropogenic Activities ◽  
Geographical Location ◽  
Soil Samples ◽  
Rrna Gene ◽  
Illumina Platform ◽  
Sulphate Reducing Bacteria ◽  
Physico Chemical ◽  
Reducing Bacteria

AbstractThis study reports the analyses of the microbiome of the estuarine soil of mangroves of the Arabian Sea. Mangroves soil samples were collected from 12 locations of Arabian Sea coast of Maharashtra, India. 16S rRNA gene V3–V4 region amplicon sequencing was performed using the Miseq Illumina platform to identify the microbial communities present in the mangroves ecosystem. The metagenomics analysis provided an insight into the abundance, diversity and spatial variations in the mangrove microbial communities in relation to physico-chemical parameters and revealed that Proteobacteria, Flavobacteria and Planctomycetes are abundant in mangroves system. The differences in bacterial abundance, composition and diversity can partly be attributed to the physico-chemical characteristics of the samples, geographical location and anthropogenic activities in the locality. High numbers of sulphate reducing bacteria accompanied with methanogen bacteria were characteristic of Indian mangroves. The results obtained in the current study indicate rich species diversity and add valuable insights about the diversity of microbial communities of the mangroves in Maharashtra along the west coast of India and can provide better information for effective measures for conservation of mangroves. GIS based prediction suggest that the sulphur utilizing communities are under threat from anthropogenic activities and may decline in future if immediate measures are not implemented.

scholarly journals Keystone Genes Confer Superior Performance in Hyperthermophilic Composting

2021 ◽  
Author(s):  
Peng Cui ◽  
Hanpeng Liao ◽  
Chaofan Ai ◽  
Zhongbing Xu ◽  
Zhi Chen ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Relative Abundance ◽  
Anthropogenic Activities ◽  
N Cycling ◽  
Superior Performance ◽  
Rrna Gene ◽  
Sequencing Data ◽  
Solid Waste Disposal ◽  
Organic Solid ◽  
Improved Performance

Abstract Background: Large amounts of organic solid wastes originating from anthropogenic activities have imposed enormous pressure on the environment and human health. Our previous studies showed that compared with conventional thermophilic composting (cTC), hyperthermophilic composting (hTC) exhibits superior performance in organic solid waste disposal by providing advantages such as improved composting temperature, nitrogen conservation (NC), nitrous oxide (N2O) mitigation and germination index (GI). However, it remains unclear how hTC communities drive improved performance. Here, we used GeoChip 5.0M coupled with high-throughput 16S rRNA gene sequencing data to investigate the variations in carbon (C)-degrading and nitrogen (N)-cycling genes and microbial communities and their linkages with selected performance indices (composting temperature, NC, N2O emission rate and GI) in hTC and cTC in factory-scale experiments, aiming to identify the keystone biotic drivers for the improved performance. Results: We showed that hTC significantly altered functional composition structures compared with those in cTC, which was driven by taxonomic shift in microbial communities. Specifically, hTC significantly increased the relative abundance of C-degrading genes and decreased the relative abundance of N-cycling genes during composting. These significantly shifted genes were the keystone genes dominating the improved performance of hTC, as indicated by a random forest model. Furthermore, network and partial least squares path modeling analysis suggested that the keystone genes continued to dominantly drive the improved performance after multiple biotic (community composition and other genes) drivers were simultaneously considering in hTC. Conclusions: Together, our study provides evidence that keystone genes potentially play a pivotal role in improving composting temperature, N2O mitigation, NC and GI in hTC and emphasizes the importance of understanding the variation in functions for targeted manipulation of composting practices.

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