Use of convertible flow cells to simulate the impacts of anthropogenic activities on river biofilm bacterial communities

2019 ◽  
Vol 653 ◽  
pp. 148-156 ◽  
Author(s):  
Kailingli Liao ◽  
Yaohui Bai ◽  
Yang Huo ◽  
Zhiyu Jian ◽  
Wanchao Hu ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Flow Cells ◽  
River Biofilm

Microbial Diversity in the Glacial Ecosystem of Antarctic, Arctic, and Tibetan Plateau: Properties and Response to the Environmental Condition

2020 ◽  
Vol 9 (1) ◽  
pp. 231-250
Author(s):  
Birendra Prasad Sharma ◽  
Subash Adhikari ◽  
Ganesh Paudel ◽  
Namita Paudel Adhikari
Keyword(s):  
Tibetan Plateau ◽  
Microbial Diversity ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Anthropogenic Activities ◽  
Relevant Literature ◽  
The Tibetan Plateau ◽  
Polar Regions ◽  
Cold Temperatures ◽  
Bacterial Phyla

Microorganisms, as successive members of the food web, play a major role in biological processes. They are found in environments ranging from extremely hot to harsh cold temperatures. Thus, the study of bacterial communities in various ecosystems is of great concern around the world. The glacier is one of the parts of the cryosphere, which is the key component and sensitive indicator of climatic and environmental changes. A glacial ecosystem is a habitat for various microorganisms, i.e., autotrophic and heterotrophic. Different physicochemical parameters like temperature, pH, electrical conductivity, the input of nutrient concentration, precipitation, ions concentrations, etc. influence the microbial diversity in the glacial ecosystem for their metabolic processes. Successive studies of bacterial communities in the Himalayan glacial ecosystem are reliable proxies to know the relationships between microbial biodiversity and climate change since the Himalayan glaciers are free from anthropogenic activities. After the study of the relevant literature, it is clear that the researches. have been carried out in the Polar Regions, and the Tibetan plateau mainly focused on the glacial ecosystem. This review concluded that Proteobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Verrucomicrobia, and Actinobacteria were the most dominant bacterial phyla via 16S rRNA clone libraries and Illumina MiSeq. Alter in landscapes, nutrient cycles, exposure of light, shifting on the concentration of different elements, glacier retreats were the major components for survival strength of dominant bacterial phyla. However, limited studies on the glacial ecosystem of the Himalayas have been published. Thus, the study of bacterial abundance, diversity, and community in the Himalayas will help plug this research gap.

scholarly journals Antibiotic Resistance Genes in Phage Particles from Antarctic and Mediterranean Seawater Ecosystems

2020 ◽  
Vol 8 (9) ◽  
pp. 1293
Author(s):  
Pedro Blanco-Picazo ◽  
Gabriel Roscales ◽  
Daniel Toribio-Avedillo ◽  
Clara Gómez-Gómez ◽  
Conxita Avila ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Antibiotic Resistance Genes ◽  
Mediterranean Area ◽  
Mediterranean Coast ◽  
Anthropogenic Pressure ◽  
The Mediterranean ◽  
The Antarctic

Anthropogenic activities are a key factor in the development of antibiotic resistance in bacteria, a growing problem worldwide. Nevertheless, antibiotics and resistances were being generated by bacterial communities long before their discovery by humankind, and might occur in areas without human influence. Bacteriophages are known to play a relevant role in the dissemination of antibiotic resistance genes (ARGs) in aquatic environments. In this study, five ARGs (blaTEM, blaCTX-M-1, blaCTX-M-9, sul1 and tetW) were monitored in phage particles isolated from seawater of two different locations: (i) the Mediterranean coast, subjected to high anthropogenic pressure, and (ii) the Antarctic coast, where the anthropogenic impact is low. Although found in lower quantities, ARG-containing phage particles were more prevalent among the Antarctic than the Mediterranean seawater samples and Antarctic bacterial communities were confirmed as their source. In the Mediterranean area, ARG-containing phages from anthropogenic fecal pollution might allow ARG transmission through the food chain. ARGs were detected in phage particles isolated from fish (Mediterranean, Atlantic, farmed, and frozen), the most abundant being β-lactamases. Some of these particles were infectious in cultures of the fecal bacteria Escherichia coli. By serving as ARG reservoirs in marine environments, including those with low human activity, such as the Antarctic, phages could contribute to ARG transmission between bacterial communities.

scholarly journals Habitat disturbance influences the skin microbiome of a rediscovered neotropical-montane frog

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Randall R. Jiménez ◽  
Gilbert Alvarado ◽  
José Sandoval ◽  
Simone Sommer
Keyword(s):  
Relative Abundance ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Defense Mechanism ◽  
Anthropogenic Activities ◽  
Habitat Disturbance ◽  
Amphibian Declines ◽  
Stress Factors ◽  
Skin Microbiome ◽  
Disturbed Habitats

Abstract Background The skin microbiome serves as a first line defense against pathogens in vertebrates. In amphibians, it has the potential to protect against the chytrid fungus Batrachochytrium dendrobatis (Bd), a likely agent of amphibian declines. Alteration of the microbiome associated with unfavorable environmental changes produced by anthropogenic activities may make the host more susceptible to pathogens. Some amphibian species that were thought to be “extinct” have been rediscovered years after population declines in the late 1980s probably due to evolved Bd-resistance and are now threatened by anthropogenic land-use changes. Understanding the effects of habitat disturbance on the host skin microbiome is relevant for understanding the health of these species, along with its susceptibility to pathogens such as Bd. Here, we investigate the influence of habitat alteration on the skin bacterial communities as well as specifically the putative Bd-inhibitory bacterial communities of the montane frog Lithobates vibicarius. This species, after years of not being observed, was rediscovered in small populations inhabiting undisturbed and disturbed landscapes, and with continuous presence of Bd. Results We found that cutaneous bacterial communities of tadpoles and adults differed between undisturbed and disturbed habitats. The adults from disturbed habitats exhibited greater community dispersion than those from undisturbed habitats. We observed a higher richness of putative Bd-inhibitory bacterial strains in adults from disturbed habitats than in those from undisturbed habitats, as well as a greater number of these potential protective bacteria with a high relative abundance. Conclusions Our findings support the microbial “Anna Karenina principle”, in which disturbance is hypothesized to cause greater microbial dispersion in communities, a so-called dysbiosis, which is a response of animal microbiomes to stress factors that decrease the ability of the host or its microbiome to regulate community composition. On the positive side, the high richness and relative abundance of putative Bd-inhibitory bacteria may indicate the development of a defense mechanism that enhances Bd-protection, attributed to a co-occurrence of more than 30-years of host and pathogen in these disturbed habitats. Our results provide important insight into the influence of human-modified landscapes on the skin microbiome and health implications of Bd-survivor species.

Comparison of bacterial communities associated withXestospongia testudinaria, sediment and seawater in a Singaporean coral reef ecosystem

2018 ◽  
Vol 99 (2) ◽  
pp. 331-342
Author(s):  
A.C.C. Pires ◽  
D.F.R. Cleary ◽  
A.R.M. Polónia ◽  
S.C. Lim ◽  
N.J. De Voogd ◽  
...  
Keyword(s):  
Coral Reef ◽  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Rrna Gene ◽  
Organic Substrates ◽  
Bacterial Symbionts ◽  
Coral Reef Ecosystem ◽  
Sulphur Bacteria ◽  
Reducing Bacteria ◽  
Reef Ecosystem

Despite alterations caused by anthropogenic activities in Singaporean coral reefs, the sponge communities are quite diverse andXestospongia testudinariais one of the most common sponge species. In the present study, we used 16S rRNA gene barcoded pyrosequencing to characterize and compare bacterial communities from different biotopes (sponge, seawater and sediment) and to identify dominant bacterial symbionts ofX. testudinariain a Singaporean coral reef ecosystem. Our results showed that biotope appears to affect the richness, composition and abundance of bacterial communities. Proteobacteria was the most abundant phylum in sediment and seawater whilst Chloroflexi was more abundant inX. testudinaria.Members of the order Caldilineales (fermentation of organic substrates), Chromatiales (purple sulphur bacteria), Rhodospirillales (purple non-sulphur bacteria) and Syntrophobacterales (sulphate-reducing bacteria) were relatively more abundant inX. testudinariasamples.

scholarly journals Quality of Irrigation Water Affects Soil Functionality and Bacterial Community Stability in Response to Heat Disturbance

2017 ◽  
Vol 84 (4) ◽  
Author(s):  
Sammy Frenk ◽  
Yitzhak Hadar ◽  
Dror Minz
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Resource Availability ◽  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Bacterial Community Composition ◽  
Treated Wastewater ◽  
Soil Bacterial Communities ◽  
High Resource ◽  
Soil Bacterial

ABSTRACTAnthropogenic activities alter the structure and function of a bacterial community. Furthermore, bacterial communities structured by the conditions the anthropogenic activities present may consequently reduce their stability in response to an unpredicted acute disturbance. The present mesocosm-scale study exposed soil bacterial communities to different irrigation water types, including freshwater, fertilized freshwater, treated wastewater, and artificial wastewater, and evaluated their response to a disturbance caused by heat. These effectors may be considered deterministic and stochastic forces common in agricultural operations of arid and semiarid regions. Bacterial communities under conditions of high mineral and organic carbon availability (artificial wastewater) differed from the native bacterial community and showed a proteobacterial dominance. These bacterial communities had a lower resistance to the heat treatment disturbance than soils under conditions of low resource availability (high-quality treated wastewater or freshwater). The latter soil bacterial communities showed a higher abundance of operational taxonomic units (OTUs) classified asBacilli. These results were elucidated by soil under conditions of high resource availability, which lost higher degrees of functional potential and had a greater bacterial community composition change. However, the functional resilience, after the disturbance ended, was higher under a condition of high resource availability despite the bacterial community composition shift and the decrease in species richness. The functional resilience was directly connected to the high growth rates of certainBacteroidetesand proteobacterial groups. A high stability was found in samples that supported the coexistence of both resistant OTUs and fast-growing OTUs.IMPORTANCEThis report presents the results of a study employing a hypothesis-based experimental approach to reveal the forces involved in determining the stability of a soil bacterial community to disturbance. The resultant postdisturbance bacterial community composition dynamics and functionality were analyzed. The paper demonstrates the relatedness of community structure and stability under cultivation conditions prevalent in an arid area under irrigation with water of different qualities. The use of common agricultural practices to demonstrate these features has not been described before. The combination of a fundamental theoretical issue in ecology with common and concerning disturbances caused by agricultural practice makes this study unique. Furthermore, the results of the present study have applicable importance regarding soil conservation, as it enables a better characterization and monitoring of stressed soil bacterial communities and possible intervention to reduce the stress. It will also be of valued interest in coming years, as fresh water scarcity and the use of alternative water sources are expected to rise globally.

scholarly journals Microbiome of two predominant seagrass species of the Kenyan coast, Enhalus acoroides and Thalassodendron ciliatum

2018 ◽  
Author(s):  
Davies Kiambi Kaimenyi ◽  
Etienne P De Villiers ◽  
Joyce Ngoi ◽  
James B Ndiso ◽  
Santie M De Villiers
Keyword(s):  
Microbial Communities ◽  
Water Samples ◽  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Seagrass Beds ◽  
Seagrass Species ◽  
Microbial Composition ◽  
Seagrass Meadows ◽  
Enhalus Acoroides ◽  
Kenyan Coast

Background. Metagenomics studies have reported on the complexity of microbiomes associated with seagrass and can provide critical insights into the sustainable use and conservation of seagrasses. Recent conservation activities in Kenya focused mainly on coral reefs and mangrove forests with little direct action taken to conserve seagrass meadows. Pollution, over-exploitation of marine resources and minimal efforts towards enforcement of conservation laws of marine environments, have caused degradation and defoliation of seagrass habitats. Little is known about the microbes associated with seagrass species in Kenya and this study aimed to characterize the genetic diversity of the microbiomes of two prominent seagrass species, Enhalus acoroides and Thallasodendron ciliatum, which are the most commonly occurring species. Methods. Replicate microbiome samples were collected from leaves, roots, sediment and water columns associated with the two seagrass species from two sites on the Kenyan coast. The microbial communities of the samples were characterized and compared using 16S ribosomal RNA gene PCR and sequencing. Microbiome features including diversity and taxonomic composition were used to compare within and between sample types and sites. Results. Leaf samples from both E. acoroides and T. ciliatum had significantly different microbial communities comparted to root and sediment samples, revealing a diversity gradient with lowest diversity in water samples and highest in sediment. There were no significant variation in seagrass microbial composition associated with leaf and rhizosphere microbiomes of either E. acoroides or T. ciliatum. However, we did see a difference between water samples associated with each seagrass species. Discussion. This study of the microbiomes associated with the sediments, roots, leaves and surrounding water of E. acoroides and T. ciliatum, included a limited number of samples from a small geographic area, providing a valuable first assessment of the microbial diversity of seagrass beds on the Kenyan coast. We found no significant differences between the plant-associated bacterial communities of the two-seagrass species investigated. Significant differences however, were observed amongst leaf-, root-, sediment- and water-associated bacterial communities. This work will contribute to understanding the dynamic environment of seagrass beds and will contribute to helping conserving and re-establishing seagrass beds degraded by due to anthropogenic activities.

scholarly journals Assessments of Bacterial Community Shifts in Sediments along the Headwaters of São Francisco River, Brazil

Conservation ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 91-105
Author(s):  
Marcos de Paula ◽  
Thiago Augusto Costa Costa Silva ◽  
Amanda Soriano Araújo ◽  
Gustavo Augusto Lacorte
Keyword(s):  
Bacterial Community ◽  
River Basin ◽  
High Intensity ◽  
Bacterial Communities ◽  
Anthropogenic Activities ◽  
Freshwater Ecosystems ◽  
Community Diversity ◽  
Anthropogenic Activity ◽  
Sao Francisco River ◽  
São Francisco River

Sustainable use of freshwater resources for human civilization needs requires the assessment and monitoring of freshwater health, and bacterial communities from riverbed sediments have been shown to be susceptible to chronic anthropogenic disturbances in freshwater ecosystems. Here, we took advantage of the occurrence of well-recognized adjacent sections from the Upper São Francisco River basin with well-recognized levels of anthropogenic activity intensity to test the applicability of sediment bacterial communities as bioindicators of impacts on freshwater ecosystems. We applied 16S amplicon sequencing to estimate the diversity and composition of bacterial communities from 12 sampling sites across the Upper São Francisco River basin, classified as being of no, low, or high intensity of anthropogenic activities, and used diversity metrics and LEfSe to compare the patterns of community structure. Our results revealed that accessed sediment environments associated with land areas with a high intensity of anthropogenic activities presented the lowest levels of community diversity, and the bacterial community compositions of these environments were significantly different from the other sampled areas. Our findings can be considered a source of evidence for the usefulness of bacterial community-based approaches as a tool for diagnosis and monitoring of ecosystem health in areas of vulnerable freshwater environments, and can even be incorporated into regular water quality programs.

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