scholarly journals Multicellular and unicellular responses of microbial biofilms to stress

2020 ◽  
Vol 401 (12) ◽  
pp. 1365-1374
Author(s):  
Daniel K.H. Rode ◽  
Praveen K. Singh ◽  
Knut Drescher
Keyword(s):  
Microbial Communities ◽  
Stress Responses ◽  
Spatial Scales ◽  
Organizational Level ◽  
Internal Stresses ◽  
Microbial Life ◽  
Microbial Biofilms ◽  
Applied Stresses

AbstractBiofilms are a ubiquitous mode of microbial life and display an increased tolerance to different stresses. Inside biofilms, cells may experience both externally applied stresses and internal stresses that emerge as a result of growth in spatially structured communities. In this review, we discuss the spatial scales of different stresses in the context of biofilms, and if cells in biofilms respond to these stresses as a collection of individual cells, or if there are multicellular properties associated with the response. Understanding the organizational level of stress responses in microbial communities can help to clarify multicellular functions of biofilms.

scholarly journals Stressor interactions under differential exogenous microbial exposure in Daphnia magna

2021 ◽  
Author(s):  
Shira Houwenhuyse ◽  
Lore Bulteel ◽  
Naina Goel ◽  
Isabel Vanoverberghe ◽  
Ellen Decaestecker
Keyword(s):  
Body Size ◽  
Microbial Communities ◽  
Daphnia Magna ◽  
Stress Responses ◽  
Multiple Stressors ◽  
Natural Environments ◽  
Laboratory Setting ◽  
Natural Conditions ◽  
Aspergillus Aculeatus ◽  
Diverse Microbial Community

Studies on stressor responses are often performed in controlled laboratory settings. The microbial communities in laboratory setting often differ from the natural environment, which could ultimately be reflected in different stress responses. In this study, we investigated how stressor responses differed between laboratory and natural conditions in Daphnia magna when exposed to single or multiple stressors. Daphnia individuals were exposed to the toxic cyanobacterium Microcystis aeruginosa and a fungal infection, Aspergillus aculeatus like type. Three genotypes were included to investigate genotype-specific responses. Survival, reproduction and body size were monitored for three weeks and gut microbial communities were sampled and characterized at the end of the experiment. Our study shows that natural environments have a more diverse microbial community compared with laboratory conditions, which was ultimately reflected in the gut microbiomes after inoculation. Stressor responses in Daphnia were affected by their bacterial environment for survival, but not for fecundity and body size. Fecuntiy and body size did show a main stressor effect, which could possibly be linked with stessor-specific microbiomes (for Microcystis and the combined stressor treatment). In addition, genotype-specific responses were detected for survival and fecundity, which could be linked with the selective capabilities of the Daphnia genotypes to select beneficial or neutral microbial stains from the environment.

scholarly journals Local versus site-level effects of algae on coral microbial communities

2021 ◽  
Vol 8 (9) ◽  
pp. 210035
Author(s):  
Amy A. Briggs ◽  
Anya L. Brown ◽  
Craig W. Osenberg
Keyword(s):  
Microbial Communities ◽  
Spatial Scales ◽  
French Polynesia ◽  
Negative Effects ◽  
Ecological Processes ◽  
Antagonistic Effects ◽  
Alpha And Beta Diversity ◽  
Macroalgal Cover ◽  
Coral Microbiome ◽  
Turf Algae

Microbes influence ecological processes, including the dynamics and health of macro-organisms and their interactions with other species. In coral reefs, microbes mediate negative effects of algae on corals when corals are in contact with algae. However, it is unknown whether these effects extend to larger spatial scales, such as at sites with high algal densities. We investigated how local algal contact and site-level macroalgal cover influenced coral microbial communities in a field study at two islands in French Polynesia, Mo'orea and Mangareva. At 5 sites at each island, we sampled prokaryotic microbial communities (microbiomes) associated with corals, macroalgae, turf algae and water, with coral samples taken from individuals that were isolated from or in contact with turf or macroalgae. Algal contact and macroalgal cover had antagonistic effects on coral microbiome alpha and beta diversity. Additionally, coral microbiomes shifted and became more similar to macroalgal microbiomes at sites with high macroalgal cover and with algal contact, although the microbial taxa that changed varied by island. Our results indicate that coral microbiomes can be affected by algae outside of the coral's immediate vicinity, and local- and site-level effects of algae can obscure each other's effects when both scales are not considered.

scholarly journals A Suppressor Mutation That Creates a Faster and More Robust σE Envelope Stress Response

2016 ◽  
Vol 198 (17) ◽  
pp. 2345-2351 ◽  
Author(s):  
Anna Konovalova ◽  
Jaclyn A. Schwalm ◽  
Thomas J. Silhavy
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Novel Mutation ◽  
Signal Transduction Pathway ◽  
Normal Growth ◽  
Internal Stresses ◽  
Content Type ◽  
Envelope Stress ◽  
Genetic Perturbations ◽  
Periplasmic Stress

ABSTRACTThe σE envelope stress response is an essential signal transduction pathway which detects and removes mistargeted outer membrane (OM) β-barrel proteins (OMPs) in the periplasm ofEscherichia coli. It relies on σE, an alternative sigma factor encoded by therpoEgene. Here we report a novel mutation, a nucleotide change of C to A in the third base of the second codon, which increases levels of σE (rpoE_S2R). TherpoE_S2Rmutation does not lead to the induction of the stress response during normal growth but instead changes the dynamics of induction upon periplasmic stress, resulting in a faster and more robust response. This allows cells to adapt faster to the periplasmic stress, avoiding lethal accumulation of unfolded OMPs in the periplasm caused by severe defects in the OMP assembly pathway.IMPORTANCESurvival of bacteria under conditions of external or internal stresses depends on timely induction of stress response signaling pathways to regulate expression of appropriate genes that function to maintain cellular homeostasis. Previous studies have shown that strong preinduction of envelope stress responses can allow bacteria to survive a number of lethal genetic perturbations. In our paper, we describe a unique mutation that enhances kinetics of the σE envelope stress response pathway rather than preinducing the response. This allows bacteria to quickly adapt to sudden and severe periplasmic stress.

scholarly journals Viruses of Polar Aquatic Environments

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 189 ◽  
Author(s):  
Sheree Yau ◽  
Mansha Seth-Pasricha
Keyword(s):  
Community Dynamics ◽  
Spatial Scales ◽  
Extreme Environments ◽  
Cold Climate ◽  
Polar Regions ◽  
Microbial Life ◽  
The North ◽  
Cellular Life ◽  
Antarctic Continent ◽  
Cycling Of Nutrients

The poles constitute 14% of the Earth’s biosphere: The aquatic Arctic surrounded by land in the north, and the frozen Antarctic continent surrounded by the Southern Ocean. In spite of an extremely cold climate in addition to varied topographies, the polar aquatic regions are teeming with microbial life. Even in sub-glacial regions, cellular life has adapted to these extreme environments where perhaps there are traces of early microbes on Earth. As grazing by macrofauna is limited in most of these polar regions, viruses are being recognized for their role as important agents of mortality, thereby influencing the biogeochemical cycling of nutrients that, in turn, impact community dynamics at seasonal and spatial scales. Here, we review the viral diversity in aquatic polar regions that has been discovered in the last decade, most of which has been revealed by advances in genomics-enabled technologies, and we reflect on the vast extent of the still-to-be explored polar microbial diversity and its “enigmatic virosphere”.

scholarly journals Insights into the Variations of Hao-Dependent Nitrifying and Nir-Dependent Denitrifying Microbial Communities in Ammonium-Graduated Lake Environments

2019 ◽  
Vol 9 (16) ◽  
pp. 3229
Author(s):  
Zhao ◽  
Chen ◽  
Qu ◽  
Jin ◽  
Zheng ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Microbial Communities ◽  
Relative Abundance ◽  
Spatial Scales ◽  
Biogeochemical Cycles ◽  
Nitrifying Bacteria ◽  
Microbial Populations ◽  
High Nitrogen ◽  
Hydroxylamine Oxidoreductase ◽  
Nitrosomonas Oligotropha

Biological nitrification and denitrification play significant roles in nitrogen-associated biogeochemical cycles. However, our understanding of the spatial scales at which microbial communities act and vary is limited. We used gene-specific metagenomic PCR to explore changes in nitrifying and denitrifying microbial communities within pristine lake and its branches, where the ammonium and dissolved organic carbon (DOC) concentrations form a gradient. The biomarkers hydroxylamine oxidoreductase and nitrite reductase genes indicated that strong relationships exist between the diversities and community structures of denitrifiers and ammonium gradients. It showed that the Nitrosomonas oligotropha cluster dominates the nitrifying bacteria in low-nutrition environments, while a new Nitrosomonas ureae cluster accounted for nearly 80% of the nitrifying bacteria in high-nitrogen environments. The distribution and diversity of nirS/K-dependent denitrifiers in the various habitats were similar, but predominantly affiliated with unknown clusters. Moreover, the abundance of all the hao genes dramatically outnumbered that of nir genes. The relative abundance of hao was clearly higher during eutrophication (13.60%) than during oligotrophy (5.23%), whereas that of nirS showed opposite tendencies. Overall, this study provides valuable comparative insights into the shifts in nitrifying and denitrifying microbial populations in lake environments with ammonium gradients, suggesting that unique dominant denitrifiers probably play an important role in the nitrogen cycle.

scholarly journals Connecting mercury science to policy: from sources to seafood

2016 ◽  
Vol 31 (1) ◽  
Author(s):  
Celia Y. Chen ◽  
Charles T. Driscoll ◽  
Kathleen F. Lambert ◽  
Robert P. Mason ◽  
Elsie M. Sunderland
Keyword(s):  
Spatial Scales ◽  
Organizational Level ◽  
Past Century ◽  
International Policy ◽  
Ecosystem Research ◽  
Surface Ocean ◽  
The Past ◽  
Harmful Effects ◽  
Binding Agreement ◽  
Hg Pollution

AbstractMercury (Hg) is a global contaminant whose presence in the biosphere has been increased by human activity, particularly coal burning/energy production, mining, especially artisanal scale gold mining, and other industrial activities. Mercury input to the surface ocean has doubled over the past century leading governments and organizations to take actions to protect humans from the harmful effects of this toxic element. Recently, the UN Environmental Program led 128 countries to negotiate and sign a legally binding agreement, the 2013 Minimata Convention, to control Hg emissions and releases to land and water globally. In an effort to communicate science to this emerging international policy, the Dartmouth Superfund Research Program formed the Coastal and Marine Mercury Ecosystem Research Collaborative (C-MERC) in 2010 that brought together more than 70 scientists and policy experts to analyze and synthesize the science on Hg pollution in the marine environment from Hg sources to MeHg in seafood. The synthesis of the science revealed that the sources and inputs of Hg and their pathways to human exposure are largely determined by ecosystem spatial scales and that these spatial scales determine the organizational level of policies. The paper summarizes the four major findings of the report.

scholarly journals Structure of Chimpanzee Gut Microbiomes across Tropical Africa

mSystems ◽  
2021 ◽  
Author(s):  
Clifton P. Bueno de Mesquita ◽  
Lauren M. Nichols ◽  
Matthew J. Gebert ◽  
Caihong Vanderburgh ◽  
Gaëlle Bocksberger ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Microbial Communities ◽  
Tool Use ◽  
Gut Microbiome ◽  
Spatial Scales ◽  
Wild Chimpanzee ◽  
Tropical Africa ◽  
Report Data

Gut microbial communities are drivers of primate physiology and health, but the factors that influence the gut microbiome in wild primate populations remain largely undetermined. We report data from a continent-wide survey of wild chimpanzee gut microbiota and highlight the effects of genetics, vegetation, and potentially even tool use at different spatial scales on the chimpanzee gut microbiome, including bacteria, archaea, and eukaryotic parasites.

scholarly journals Two different microbial communities did not cause differences in occlusion of particulate organic matter in a sandy agricultural soil

2016 ◽  
Author(s):  
Frederick Büks ◽  
Philip Rebensburg ◽  
Peter Lentzsch ◽  
Martin Kaupenjohann
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Particulate Organic Matter ◽  
Agricultural Soil ◽  
Agricultural Soils ◽  
Soil Aggregates ◽  
Soil Extract ◽  
Microbial Life ◽  
Physico Chemical ◽  
Airborne Microbes

Abstract. Apart from physico-chemical interactions between soil components, microbial life is assumed to be an important factor of soil structure forming processes. Bacterial exudates, the entanglement by fungal hypae and bacterial pseudomycelia as well as fungal glomalin are supposed to provide the occlusion of particulate organic matter (POM) through aggregation of soil particles. This work investigates the resilience of POM occlusion in face of different microbial communities under controlled environmental conditions. We hypothesized that the formation of different communities would cause different grades of POM occlusion. For this purpose samples of a sterile sandy agricultural soil were incubated for 76 days in bioreactors. Particles of pyrochar from pine wood were added as POM analogue. One variant was inoculated with a native soil extract, whereas the control was infected by airborne microbes. A second control soil remained non-incubated. During the incubation, soil samples were taken for taxon-specific qPCR to determine the abundance of Eubacteria, Fungi, Archaea, Acidobacteria, Actinobacteria, α-Proteobacteria and β-Proteobacteria. After the incubation soil aggregates (100–2000 μm) were collected by sieving and disaggregated using ultrasound to subject the released POM to an analysis of organic carbon (OC). Our results show, that the eubacterial DNA of both incubated variants reached a similar concentration after 51 days. However, the structural composition of the two communities was completely different. The soil-born variant was dominated by Acidobacteria, Actinobacteria and an additional fungal population, whereas the air-born variant mainly contained β-Proteobacteria. Both variants showed a strong occlusion of POM into aggregates during the incubation. Yet, despite the different population structure, there were only marginal differences in the release of POM along with the successive destruction of soil aggregates by ultrasonication. This leads to the tentative assumption that POM occlusion in agricultural soils could be resilient in face of changing microbial communities.

scholarly journals Environmental Water and Sediment Microbial Communities Shape Intestine Microbiota for Host Health: The Central Dogma in an Anthropogenic Aquaculture Ecosystem

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhijian Huang ◽  
Dongwei Hou ◽  
Renjun Zhou ◽  
Shenzheng Zeng ◽  
Chengguang Xing ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Intestinal Microbiota ◽  
Spatial Scales ◽  
Animal Health ◽  
Large Contribution ◽  
Shrimp Culture ◽  
Central Dogma ◽  
Water And Sediment ◽  
Pond Ecosystem ◽  
Host Health

From increasing evidence has emerged a tight link among the environment, intestine microbiota, and host health status; moreover, the microbial interaction in different habitats is crucial for ecosystems. However, how the environmental microbial community assembly governs the intestinal microbiota and microbial communities of multiple habitats contribute to the metacommunity remain elusive. Here, we designed two delicate experiments from temporal and spatial scales in a shrimp culture pond ecosystem (SCPE). Of the SCPE metacommunity, the microbial diversity was mainly contributed to by the diversity of–βIntraHabitats and βInterHabitats, and water and sediment communities had a large contribution to the shrimp intestine community as shown by SourceTracker and Sloan neutral community model analyses. Also, phylogenetic bin-based null model results show that microbial assembly of three habitats in the SCPE appeared to be largely driven by stochastic processes. These results enrich our understanding of the environment–intestinal microbiota–host health closely linked relationship, making it possible to be the central dogma for an anthropogenic aquaculture ecosystem. Our findings enhance the mechanistic understanding of microbial assembly in the SCPE for further analyzing metacommunities, which has important implications for microbial ecology and animal health.

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