scholarly journals A distinct and active bacterial community in cold oxygenated fluids circulating beneath the western flank of the Mid-Atlantic ridge

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Julie L. Meyer ◽  
Ulrike Jaekel ◽  
Benjamin J. Tully ◽  
Brian T. Glazer ◽  
C. Geoffrey Wheat ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Elevated Temperatures ◽  
Geochemical Composition ◽  
Crustal Fluid ◽  
Functional Potential ◽  
Mid Atlantic Ridge ◽  
Bacterial Groups ◽  
Insight Into

Abstract The rock-hosted, oceanic crustal aquifer is one of the largest ecosystems on Earth, yet little is known about its indigenous microorganisms. Here we provide the first phylogenetic and functional description of an active microbial community residing in the cold oxic crustal aquifer. Using subseafloor observatories, we recovered crustal fluids and found that the geochemical composition is similar to bottom seawater, as are cell abundances. However, based on relative abundances and functional potential of key bacterial groups, the crustal fluid microbial community is heterogeneous and markedly distinct from seawater. Potential rates of autotrophy and heterotrophy in the crust exceeded those of seawater, especially at elevated temperatures (25 °C) and deeper in the crust. Together, these results reveal an active, distinct, and diverse bacterial community engaged in both heterotrophy and autotrophy in the oxygenated crustal aquifer, providing key insight into the role of microbial communities in the ubiquitous cold dark subseafloor biosphere.

Metagenome analyses reveal the role of Clostridium perfringens in alfalfa silage anaerobic deterioration

2020 ◽  
Vol 367 (8) ◽  
Author(s):  
Mingli Zheng ◽  
Dongze Niu ◽  
Di Jiang ◽  
Rongrong Li ◽  
Lin Meng ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Clostridium Perfringens ◽  
Relative Abundance ◽  
Dominant Role ◽  
Ammonia Nitrogen ◽  
Fermentation Products ◽  
Microbial Community Analyses ◽  
Alfalfa Silage

ABSTRACT The clostridial fermentation caused by the outgrowth of Clostridia was mainly responsible for the silage anaerobic deterioration. Our previous results showed that Clostridium perfringens dominated the clostridial community in poor-fermented alfalfa silage. This study was conducted to further examine the role of C. perfringens in silage anaerobic deterioration through fermentation products and the microbial community analyses. Direct-cut alfalfa was ensiled with C. perfringens contamination (CKC) or with the addition of Lactobacillus plantarum, sucrose and C. perfringens (LSC). Contamination with C. perfringens enhanced the clostridial fermentation in CKC silage, as indicated by high contents of butyric acid, ammonia nitrogen and Clostridia, while LSC silage was well preserved. The genera Bifidobacterium, Garciella and Clostridium dominated the bacterial community in CKC silage, while predominate genus was replaced by Lactobacillus in LSC silage. The clostridial community in CKC silage was dominated by Garciella sp. (26.9 to 58.1%) and C. tyrobutyricum (24.4 to 48.6%), while the relative abundance of C. perfringens was below 5.0%. Therefore, the effect of Clostridia contamination on ensiling fermentation was dependent on the ensilability of the silage material. Garciella sp. and C. tyrobutyricum, rather than C. perfringens, played dominant role in the clostridial fermentation in CKC silage.

scholarly journals Conservation State of Two Paintings in the Santa Margherita Cliff Cave: Role of the Environment and of the Microbial Community

2021 ◽  
Author(s):  
francesco armetta ◽  
Josue Cardenas ◽  
Eugenio Caponetti ◽  
Rosa Alduina ◽  
Alessandro Presentato ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Environmental Conditions ◽  
Middle Age ◽  
Salt Composition ◽  
The West ◽  
West Wall ◽  
Surrounding Environment ◽  
Sea Aerosol

Abstract The conservation of ancient paintings sited in humid environments is an actual challenge for restorers, because it needs the knowledge of the materials the paintings are made up and of their interaction with a peculiar surrounding environment; thus, tailored procedures and strategies aimed at restoring and preserving paintings are necessary. The Santa Margherita’s cave in Castellammare del Golfo (Trapani, Italy) is a natural cave, containing the remains of paintings, in a poor state of conservation, belonging to an ancient church dated back to the Middle Age. The present manuscript reports the monitoring of environmental conditions (i.e., temperature and humidity) in a full year as well as a study on the materials constituting the stone support and the paintings together with a survey of the microbial community. The findings allow us to define the causes which mainly involve the degradation of the paintings. In detail, the degradation of the east and the west wall occurred differently because of the exposure to the sea aerosol, which influenced the salt composition, also contributing to diversifying the bacterial community. Some specific actions to plan the conservation and restoration of paintings and to preserve the site are suggested.

scholarly journals Genomics of tailless bacteriophages in a complex lactic acid bacteria starter culture

2020 ◽  
Author(s):  
Svetlana Alexeeva ◽  
Yue Liu ◽  
Jingjie Zhu ◽  
Joanna Kaczorowska ◽  
Thijs R. H. M. Kouwen ◽  
...  
Keyword(s):  
Microbial Community ◽  
Selection Criteria ◽  
Potential Role ◽  
Starter Culture ◽  
Comparative Genome Analysis ◽  
Phage Group ◽  
Different Strains ◽  
Encoding Genes ◽  
Insight Into

Abstract Background Our previous study on a model microbial community originating from artisanal cheese fermentation starter revealed that bacteriophages not only co-exist with bacteria but also are highly abundant. To gain more insight into the potential role of prophages in the microbial community, we analysed the genomic content of 6 phage crops released by different strains in the starter culture, performed comparative genome analysis, and demonstrated their roles in phage defence of respective hosts. Results The identified prophages belong to three different subgroups of the Siphoviridae P335 phage group. Remarkably, most analysed prophages show disruptions in different tail encoding genes, resulting in a common tailless phenotype. Furthermore, a number of potentially beneficial features for the host carried by prophages were identified. The prophages carry up to 3 different phage defence systems per genome that are functional in protecting the host from foreign phage infection. Conclusion We suggest that the presumably defective prophages are a result of bacteria-phage coevolution and convey advantages to host bacteria; knowledge on the ecological role of such (defective) prophages may contribute to a refreshed look in strain selection criteria in (dairy) industry.

scholarly journals Metagenome-Assembled Genome Sequences of Acetobacterium sp. Strain MES1 and Desulfovibrio sp. Strain MES5 from a Cathode-Associated Acetogenic Microbial Community

2017 ◽  
Vol 5 (36) ◽  
Author(s):  
Daniel E. Ross ◽  
Christopher W. Marshall ◽  
Harold D. May ◽  
R. Sean Norman
Keyword(s):  
Microbial Community ◽  
Draft Genome ◽  
Genome Sequences ◽  
Comparative Analyses ◽  
Microbial Electrosynthesis ◽  
Functional Potential ◽  
Insight Into

ABSTRACT Draft genome sequences of Acetobacterium sp. strain MES1 and Desulfovibrio sp. strain MES5 were obtained from the metagenome of a cathode-associated community enriched within a microbial electrosynthesis system (MES). The draft genome sequences provide insight into the functional potential of these microorganisms within an MES and a foundation for future comparative analyses.

scholarly journals A dynamic microbial community with high functional redundancy inhabits the cold, oxic subseafloor aquifer

2017 ◽  
Author(s):  
Benjamin Tully ◽  
Charles Geoff Wheat ◽  
Brian T Glazer ◽  
Julie Huber
Keyword(s):  
Microbial Community ◽  
Community Dynamics ◽  
Carbon Fixation ◽  
Biogeochemical Cycles ◽  
Functional Redundancy ◽  
Microbial Life ◽  
Crustal Fluid ◽  
Mid Atlantic Ridge ◽  
Taxonomic Groups ◽  
A Site

The rock-hosted subseafloor crustal aquifer harbors a reservoir of microbial life that may influence global marine biogeochemical cycles. Here we utilized genomic reconstruction of crustal fluid samples from North Pond, located on the flanks of the Mid-Atlantic Ridge, a site with cold, oxic subseafloor fluid circulation within the upper basement. Twenty-one samples were collected during a two-year period at three different depths and two locations with the basaltic aquifer to examine potential microbial metabolism and community dynamics. We observed minor changes in the geochemical signatures over the two years, yet a dynamic microbial community was present in the crustal fluids that underwent large shifts in the dominant taxonomic groups. An analysis of 195 metagenome-assembled genomes (MAGs) were generated from the dataset and revealed a connection between litho- and autotrophic processes, linking carbon fixation to the oxidation of sulfide, sulfur, thiosulfate, hydrogen, and ferrous iron in a diverse group of microorganisms. Despite oxic conditions, analysis of the MAGs indicated that members of the microbial community were poised to exploit hypoxic or anoxic conditions through the use of microaerobic cytochromes and alternative electron acceptors. Temporal and spatial trends from the MAGs revealed a high degree of functional redundancy that did not correlate with the shifting microbial community membership, suggesting functional stability in mediating subseafloor biogeochemical cycles.

scholarly journals Taxonomic and nitrogen-cycling microbial community functional profiles of sugarcane and adjacent forest soils in Southeast Brazil

2021 ◽  
Vol 6 (4) ◽  
pp. 119-125
Author(s):  
Acacio Aparecido Navarrete ◽  
Eliamar Aparecida Nascimbém Pedrinho ◽  
Luciano Takeshi Kishi ◽  
Camila Cesário Fernandes ◽  
Victoria Romancini Toledo ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Nitrogen Cycling ◽  
Forest Soil ◽  
Soil Microbial Communities ◽  
Soil Bacterial Community ◽  
Sugarcane Production ◽  
Functional Potential ◽  
Southeast Brazil ◽  
Soil Bacterial

Nowadays, due to the expansion of agricultural borders, it is highly desirable to increase the sustained productivity of sugarcane cultivars using the knowledge of soil microbial communities. In this study, twelve shotgun metagenomic datasets based on genomic DNA from soil were analyzed using the Metagenomics Rapid Annotation using Subsystem Technology (MG-RAST) and Statistical Analysis of Metagenomic Profiles (STAMP) to assess differential responses for the total soil bacterial community composition and nitrogen-cycling microbial community functional potential in soils from sugarcane field with pre-harvest burning and adjacent forest in dry and wet seasons in Southeast Brazil. The soil bacterial community revealed higher abundance for Actinobacteria in forest soil than sugarcane soil in dry and wet seasons, and an opposite pattern for Proteobacteria and Planctomycetes in these soils in both seasons. The results obtained in this study based on the KEEG map suggest that the forest soil has a higher nitrogen-cycling microbial community functional potential compared to the sugarcane soil, independently of the season. The gene sequences associated with carbohydrate metabolism were the most frequent in all soil metagenomes. Taken together, the results confirm previous findings regarding the effects of forest conversion to sugarcane production area, providing new insights regarding to this conversion through the prism of the seasonality and pre-harvesting method on microbially mediated nitrogen cycle in sugarcane production fields.

scholarly journals Phycosphere Microbial Succession Patterns and Assembly Mechanisms in a Marine Dinoflagellate Bloom

2019 ◽  
Vol 85 (15) ◽  
Author(s):  
Jin Zhou ◽  
Guo-Fu Chen ◽  
Ke-Zhen Ying ◽  
Hui Jin ◽  
Jun-Ting Song ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Stochastic Processes ◽  
Algal Bloom ◽  
Microbial Succession ◽  
Free Living ◽  
Environmental Selection ◽  
Deterministic Processes ◽  
Bacterial Groups ◽  
Living Bacteria

ABSTRACT Given the ecological significance of microorganisms in algal blooming events, it is critical to understand the mechanisms regarding their distribution under different conditions. We tested the hypothesis that microbial community succession is strongly associated with algal bloom stages, and that the assembly mechanisms are cocontrolled by deterministic and stochastic processes. Community structures and underlying ecological processes of microbial populations (attached and free-living bacteria) at three algal bloom stages (pre-, during, and postbloom) over a complete dinoflagellate Scrippsiella trochoidea bloom were investigated. Both attached and free-living taxa had a strong response to the bloom event, and the latter was more sensitive than the former. The contribution of environmental parameters to microbial variability was 40.2%. Interaction analysis showed that complex positive or negative correlation networks exist in phycosphere microbes. These relationships were the potential drivers of mutualist and competitive interactions that impacted bacterial succession. Null model analysis showed that the attached bacterial community primarily exhibited deterministic processes at pre- and during-bloom stages, while dispersal-related processes contributed to a greater extent at the postbloom stage. In the free-living bacterial community, homogeneous selection and dispersal limitation dominated in the initial phase, which gave way to more deterministic processes at the two later stages. Relative contribution analyses further demonstrated that the community turnover of attached bacteria was mainly driven by environmental selection, while stochastic factors had partial effects on the assembly of free-living bacteria. Taken together, these data demonstrated that a robust link exists between bacterioplankton community structure and bloom progression, and phycosphere microbial succession trajectories are cogoverned by both deterministic and random processes. IMPORTANCE Disentangling the mechanisms shaping bacterioplankton communities during a marine ecological event is a core concern for ecologists. Harmful algal bloom (HAB) is a typical ecological disaster, and its formation is significantly influenced by alga-bacterium interactions. Microbial community shifts during the HAB process are relatively well known. However, the assembly processes of microbial communities in an HAB are not fully understood, especially the relative influences of deterministic and stochastic processes. We therefore analyzed the relative contributions of deterministic and stochastic processes during an HAB event. Both free-living and attached bacterial groups had a dramatic response to the HAB, and the relative importance of determinism versus stochasticity varied between the two bacterial groups at various bloom stages. Environmental factors and biotic interactions were the main drivers impacting the microbial shift process. Our results strengthen the understanding of the ecological mechanisms controlling microbial community patterns during the HAB process.

scholarly journals Absence of 4-Formylaminooxyvinylglycine Production by Pseudomonas fluorescens WH6 Results in Resource Reallocation from Secondary Metabolite Production to Rhizocompetence

2021 ◽  
Vol 9 (4) ◽  
pp. 717
Author(s):  
Viola A. Manning ◽  
Kristin M. Trippe
Keyword(s):  
Pseudomonas Fluorescens ◽  
Secondary Metabolite ◽  
Biofilm Formation ◽  
Transcriptome Data ◽  
Wild Type ◽  
Resource Reallocation ◽  
Functional Potential ◽  
Small Orfs ◽  
Insight Into

Pseudomonas fluorescens WH6 produces the non-proteinogenic amino acid 4-formylaminooxyvinylglycine (FVG), a secondary metabolite with antibacterial and pre-emergent herbicidal activities. The gvg operon necessary for FVG production encodes eight required genes: one regulatory (gvgR), two of unknown functional potential (gvgA and C), three with putative biosynthetic function (gvgF, H, and I), and two small ORFs (gvgB and G). To gain insight into the role of GvgA and C in FVG production, we compared the transcriptome of knockout (KO) mutants of gvgR, A, and C to wild type (WT) to test two hypotheses: (1) GvgA and GvgC play a regulatory role in FVG production and (2) non-gvg cluster genes are regulated by GvgA and GvgC. Our analyses show that, collectively, 687 genes, including the gvg operon, are differentially expressed in all KO strains versus WT, representing >10% of the genome. Fifty-one percent of these genes were similarly regulated in all KO strains with GvgC having the greatest number of uniquely regulated genes. Additional transcriptome data suggest cluster regulation through feedback of a cluster product. We also discovered that FVG biosynthesis is regulated by L-glu, L-asp, L-gln, and L-asn and that resources are reallocated in KO strains to increase phenotypes involved in rhizocompetence including motility, biofilm formation, and denitrification. Altogether, differential transcriptome analyses of mutants suggest that regulation of the cluster is multifaceted and the absence of FVG production or its downregulation can dramatically shift the lifestyle of WH6.

Plasminogen Activation In Vivo upon Intravenous Infusion of DDAVP

1992 ◽  
Vol 67 (01) ◽  
pp. 111-116 ◽  
Author(s):  
Marcel Levi ◽  
Jan Paul de Boer ◽  
Dorina Roem ◽  
Jan Wouter ten Cate ◽  
C Erik Hack
Keyword(s):  
Monoclonal Antibodies ◽  
Plasminogen Activator ◽  
Plasma Levels ◽  
Fold Increase ◽  
Fibrinolytic System ◽  
Plasminogen Activation ◽  
Plasminogen Activator Activity ◽  
Insight Into

SummaryInfusion of desamino-d-arginine vasopressin (DDAVP) results in an increase in plasma plasminogen activator activity. Whether this increase results in the generation of plasmin in vivo has never been established.A novel sensitive radioimmunoassay (RIA) for the measurement of the complex between plasmin and its main inhibitor α2 antiplasmin (PAP complex) was developed using monoclonal antibodies preferentially reacting with complexed and inactivated α2-antiplasmin and monoclonal antibodies against plasmin. The assay was validated in healthy volunteers and in patients with an activated fibrinolytic system.Infusion of DDAVP in a randomized placebo controlled crossover study resulted in all volunteers in a 6.6-fold increase in PAP complex, which was maximal between 15 and 30 min after the start of the infusion. Hereafter, plasma levels of PAP complex decreased with an apparent half-life of disappearance of about 120 min. Infusion of DDAVP did not induce generation of thrombin, as measured by plasma levels of prothrombin fragment F1+2 and thrombin-antithrombin III (TAT) complex.We conclude that the increase in plasminogen activator activity upon the infusion of DDAVP results in the in vivo generation of plasmin, in the absence of coagulation activation. Studying the DDAVP induced increase in PAP complex of patients with thromboembolic disease and a defective plasminogen activator response upon DDAVP may provide more insight into the role of the fibrinolytic system in the pathogenesis of thrombosis.

On Metaphysics and the Political: A Polemics of Reading Baudelaire in the 1930s

2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto
Keyword(s):  
Twentieth Century ◽  
Political Crisis ◽  
The Political ◽  
Modern Poetry ◽  
Progressive Politics ◽  
The World ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.

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