4 Material und Umwelt
Filtern
Erscheinungsjahr
- 2018 (32) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (32) (entfernen)
Referierte Publikation
- ja (32) (entfernen)
Schlagworte
- Bacteria (3)
- Fungi (3)
- Bioinformatics (2)
- Immunity (2)
- Phosphorus (2)
- Social (2)
- Soil (2)
- Virology (2)
- 3D printer (1)
- Alkylating agents (1)
- Antimicrobial (1)
- Antimicrobial test (1)
- Antiseptic agents (1)
- Aspergillus (1)
- BTEX (1)
- Beschichtung (1)
- Biofouling (1)
- Bioinformatics virology viruses software (1)
- Biosynthesis (1)
- Black fungi (1)
- Built environment (1)
- CEC-L-103 (1)
- Calibration transfer (1)
- Cannibalism (1)
- Chlorine (1)
- Cognitive performance (1)
- Conjugate (1)
- Corrosion (1)
- Cross-feeding (1)
- Cyanobacteria (1)
- DNA (1)
- DRIFTS (1)
- Decomposition point (1)
- Degradation (1)
- Denitrification (1)
- Dielectric heating (1)
- E. coli (1)
- Ecotoxicological tests (1)
- Ectoine (1)
- Emission (1)
- Entomopathogen (1)
- Environmental conditions (1)
- Exergie (1)
- Exocrine gland (1)
- Exposure (1)
- External (1)
- Extracellular enzymes (1)
- Fertilzer (1)
- Fusarium (1)
- GC-FID (1)
- Graphene (1)
- Graphene–bacteria interaction (1)
- Groundwater (1)
- Hospital premises (1)
- Hypopharynx (1)
- Idiopathic environmental intolerance (1)
- Indoor air quality (1)
- Indoor mycobiome (1)
- Inter-lab comparison (1)
- Isoptera (1)
- Knufia petricola (1)
- Kupfer (1)
- Labrum (1)
- Laser printer emission (1)
- Layer-by-Layer (1)
- MOF (1)
- MSWI fly ash (1)
- Magnesium (1)
- Melting point (1)
- Melting temperature (1)
- Metadata (1)
- Method development (1)
- Microwaves (1)
- Molecular Organic Frameworks (1)
- Molecular identification (1)
- Multi-scale study (1)
- Multiple chemical sensitivity (1)
- Mycotoxin (1)
- NAP-XPS (1)
- Nano-Fourier-transform infrared spectroscopy (1)
- NanoSIMS (1)
- Nitrous oxide (1)
- Non-invasive (1)
- Nonvolatile (1)
- Nostoc punctiforme (1)
- Nutrient acquisition (1)
- One-step ionic liquids synthesis (1)
- Open data (1)
- PV modules (1)
- Painting (1)
- Pest control (1)
- Phenotypic heterogeneity (1)
- Phototrophs (1)
- Pigment (1)
- Pollutant (1)
- Polyelektrolyt (1)
- Polypropylene (1)
- Polystyrene (1)
- Pot experiments (1)
- Prospective risk assessment (1)
- Proteome (1)
- Radio waves (1)
- Real-time qPCR (1)
- Reference organisms (1)
- Rhizopus (1)
- Rhizosphere effect (1)
- Rostasche (1)
- Scattering-type scanning near-field optical microscopy (s-SNOM) (1)
- Secondary P-fertilizer (1)
- Selective quantification (1)
- Sequence annotation (1)
- Sewage sludge ash (1)
- Silicon carbide (1)
- Software (1)
- Solar panels (1)
- Soldier (1)
- Sorption (1)
- Standardisation (1)
- Stoichiometric homeostasis (1)
- Subjective complaints (1)
- Surface water (1)
- Synchrotron radiation (1)
- Systematics (1)
- Targeted and nontargeted (1)
- Taxonomy (1)
- Termitoidae (1)
- Thermal treatment (1)
- Thermodynamic (1)
- Ultrafine particles (1)
- Ultrastructure (1)
- VOC (1)
- Viruses (1)
- Volatile organic compounds (1)
- Wood protection (1)
- X-ray absorption near-edge structure (XANES) spectroscopy (1)
- XPS (1)
- ZIF (1)
- Zearalenone (1)
- Zeolithe (1)
Organisationseinheit der BAM
- 4 Material und Umwelt (32)
- 4.1 Biologische Materialschädigung und Referenzorganismen (13)
- 4.0 Abteilungsleitung und andere (10)
- 1 Analytische Chemie; Referenzmaterialien (4)
- 4.2 Material-Mikrobiom Wechselwirkungen (4)
- 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (4)
- 6 Materialchemie (4)
- 1.7 Organische Spuren- und Lebensmittelanalytik (3)
- 4.3 Schadstofftransfer und Umwelttechnologien (3)
- 5 Werkstofftechnik (2)
Test methods for efficacy assessment of antimicrobial coatings are not modelled on a hospital environment, and instead use high humidity (>90%) high temperature (37 ◦C), and no airflow. Therefore, an inoculum will not dry, resulting in an antimicrobial surface exhibiting prolonged antimicrobial activity, as moisture is critical to activity. Liquids will dry quicker in a hospital ward, resulting in a reduced antimicrobial efficacy compared to the existing test, rendering the test results artificially favourable to the antimicrobial claim of the product. This study aimed to assess how hospital room environmental conditions can affect the drying time of an inoculum, and to use this data to inform test parameters for antimicrobial efficacy testing based on the hospital ward. The drying time of different droplet sizes, in a range of environmental conditions likely found in a hospital ward, were recorded (n = 630), and used to create a model to inform users of the experimental conditions required to provide a drying time similar to what can be expected in the hospital
ward. Drying time data demonstrated significant (p < 0.05) variance when humidity, temperature, and airflow were assessed. A mathematical model was created to select environmental conditions for in vitro antimicrobial efficacy testing. Drying time in different environmental conditions demonstrates that experimental set-ups affect the amount of time an inoculum stays wet, which in turn may affect the efficacy of an antimicrobial surface. This should be an important consideration for hospitals and other potential users, whilst future tests predict efficacy in the intended end-use environment.
In a controlled growth experiment we found that the cyanobacterium Nostoc punctiforme has a bulk cell 26Mg/24Mg ratio (expressed as δ26Mg) that is −0.27‰ lower than the growth solution at a pH of ca. 5.9. This contrasts with a recently published δ26Mg value that was 0.65‰ higher than growth solution for the black fungus Knufia petricola at similar laboratory conditions, interpreted to reflect loss of 24Mg during cell growth. By a mass balance model constrained by δ26Mg in chlorophyll extract we inferred the δ26 Mg value of the main Mg compartments in a cyanobacteria cell: free cytosolic Mg (−2.64‰), chlorophyll (1.85‰), and the nonchlorophyll-bonded Mg compartments like ATP and ribosomes (−0.64‰). The lower δ26Mg found in Nostoc punctiforme would thus result from the absence of significant Mg efflux during cell growth in combination with either (a) discrimination against 26Mg during uptake by desolvation of Mg or transport across protein channels or (b) discrimination against 24Mg in the membrane transporter during efflux. The model predicts the preferential incorporation of 26Mg in cells and plant organs low in Mg and the absence of isotope fractionation in those high in Mg, corroborated by a compilation of Mg isotope ratios from fungi, bacteria, and higher plants.
The evolutionary success of termites has been driven largely by a complex communication system operated by a rich set of exocrine glands. As many as 20 different exocrine organs are known in termites. While some of these organs are relatively well known, only anecdotal observations exist for others. One of the exocrine organs that has received negligible attention so far is the labral gland. In this study, we examined the structure and ultrastructure of the Labrum in soldiers of 28 termite species. We confirm that the labral gland is present in all termite species, and comprises two secretory regions located on the ventral side of the labrum and the dorso-apical part of the hypopharynx. The Labrum of Neoisoptera has a hyaline tip, which was secondarily lost in Nasutitermitinae, Microcerotermes and species with snapping soldiers. The epithelium of the gland generally consists of class 1 secretory cells, with an addition of class 3 secretory cells in some species. A common feature of the secretory cells is the abundance of smooth endoplasmic reticulum, an organelle known to produce lipidic and often volatile secretions. Our observations suggest that the labral gland is involved in communication rather than defence as previously suggested. Our study is the first to provide a comprehensive picture of the structure of the labral gland in soldiers across all Termite taxa.
In nature, the cellular environment of DNA includes not only water and ions, but also other components and co-solutes, which can exert both stabilizing and destabilizing effects on particular oligonucleotide conformations. Among them, ectoine, known as an important osmoprotectant organic co-solute in a broad range of pharmaceutical products, turns out to be of particular relevance. In this article, we study the influence of ectoine on a short single-stranded DNA fragment and on double-stranded helical B-DNA in aqueous solution by means of atomistic molecular dynamics (MD) simulations in combination with molecular theories of solution. Our results demonstrate a conformation-dependent binding behavior of ectoine, which favors the unfolded state of DNA by a combination of electrostatic and dispersion interactions. In conjunction with the Kirkwood–Buff theory, we introduce a simple Framework to compute the influence of ectoine on the DNA melting temperature. Our findings reveal a significant linear decrease of the melting temperature with increasing ectoine concentration, which is found to be in qualitative agreement with results from denaturation experiments. The outcomes of our Computer simulations provide a detailed mechanistic rationale for the surprising destabilizing influence of ectoine on distinct DNA structures.
Recent DNA-based studies have shown that the built environment is surprisingly rich in fungi. These indoor fungi – whether transient visitors or more persistent residents – may hold clues to the rising levels of human allergies and other medical and building-related health problems observed globally. The taxo¬nomic identity of these fungi is crucial in such pursuits. Molecular identification of the built mycobiome is no trivial undertaking, however, given the large number of unidentified, misidentified, and technically compromised fungal sequences in public sequence databases. In addition, the sequence metadata required to make informed taxonomic decisions – such as country and host/substrate of collection – are often lacking even from reference and ex-type sequences. Here we report on a taxonomic annotation workshop (April 10–11, 2017) organized at the James Hutton Institute/University of Aberdeen (UK) to facilitate reproducible studies of the built mycobiome. The 32 participants went through public fungal ITS bar¬code sequences related to the built mycobiome for taxonomic and nomenclatural correctness, technical quality, and metadata availability. A total of 19,508 changes – including 4,783 name changes, 14,121 metadata annotations, and the removal of 99 technically compromised sequences – were implemented in the UNITE database for molecular identification of fungi (https://unite.ut.ee/) and shared with a range of other databases and downstream resources. Among the genera that saw the largest number of changes were Penicillium, Talaromyces, Cladosporium, Acremonium, and Alternaria, all of them of significant importance in both culture-based and culture-independent surveys of the built environment.
Microplastics are increasingly entering marine, limnic and terrestrial ecosystems worldwide, where they sorb hydrophobic organic contaminants. Here, the sorption behavior of the fuel-related water contaminants benzene, toluene, ethyl benzene and xylene (BTEX) and four tertiary butyl ethers to virgin and via UV radiation aged polypropylene (PP) and polystyrene (PS) pellets was investigated. Changes in material properties due to aging were recorded using appropriate polymer characterization methods, such as differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy, and microscopy.
Pellets were exposed to water containing BTEX and the ethers at 130-190 mg/L for up to two weeks.
Aqueous sorbate concentrations were determined by headspace gas chromatography. Sorption to the polymers was correlated with the sorbate's Kow and was significant for BTEX and marginal for the ethers.
Due to substantially lower glass transition temperatures, PP showed higher sorption than PS. Aging had no effect on the sorption behavior of PP. PS sorbed less BTEX after aging due to an oxidized surface layer.
Soiling of photovoltaic (PV) systems compromises their performance causing a significant power loss and demanding periodical cleaning actions. This phenomenon raises great concerns in the solar energy field, thus leading to notable research efforts over the last decades. Soiling is caused by a dual action of dust deposition and biofouling. However, surprisingly, the microbiological contribution to PV soiling is often overlooked or underestimated. In this study, a variety of qPCR-based methods have been developed to quantify the microbial load of fungi, bacteria and phototrophs on PV panels. These protocols were evaluated by comparison with culturedependent methods, and were implemented with real solar plants for two years. The results show that the developed molecular methods are highly sensitive and reliable to monitor the microbial component of the soiling. Fungal biomass was clearly dominant in all analysed PV modules, while bacteria and phototrophs showed much lower abundance. Light microscopy and qPCR results revealed that melanised microcolonial fungi and phototrophs are the main biofilm-forming microorganisms on the studied solar panels. In particular, the fungal qPCR protocol is proposed as a useful tool for monitoring of PV soiling, and investigating the microbial contribution to specific soiling cases.
Coastal oceans receive large amounts of anthropogenic fixed nitrogen (N), most of which is denitrified in the sediment before reaching the open ocean. Sandy sediments, which are common in coastal regions, seem to play an important role in catalysing this N‐loss. Permeable sediments are characterized by advective porewater transport, which supplies high fluxes of organic matter into the sediment, but also leads to fluctuations in oxygen and nitrate concentrations. Little is known about how the denitrifying communities in these sediments are adapted to such fluctuations. Our combined results indicate that denitrification in eutrophied sandy sediments from the world's largest tidal flat system, the Wadden Sea, is carried out by different groups of microorganisms. This segregation leads to the formation of N2O which is advectively transported to the overlying waters and thereby emitted to the atmosphere. At the same time, the production of N2O within the sediment supports a subset of Flavobacteriia which appear to be specialized on N2O reduction. If the mechanisms shown here are active in other coastal zones, then denitrification in eutrophied sandy sediments may substantially contribute to current marine N2O emissions.
Surface characterisation of Escherichia coli under various conditions by near-ambient pressure XPS
(2018)
Bacteria are inherently in a hydrated state and therefore not compatible to ultra-high vacuum techniques such as XPS without prior sample preparation involving freeze drying or fast freezing.
This has changed with the development of near-ambient pressure (NAP)-XPS, which makes it possible to characterise the bacterial surface with minimal sample preparation. This paper presents NAP-XPS measurements of Escherichia coli under various NAP conditions: at 11 mbar in a humid environment, at 2 mbar after drying in the chamber, pre-dried at 4 mbar, and at 1 mbar after overnight pumping at 10^−4 mbar. The high-resolution spectra of carbon, nitrogen, and oxygen are presented and found to be in general agreement with XPS measurements from freeze-dried and fast-frozen bacteria. However, it was found that the amount of carbon components associated with polysaccharides increases relative to aliphatic carbon during drying and increases further after overnight pumping. This implies that drying has an impact on the bacterial surface.
Despite the recognized excellence of virology and bioinformatics, these two communities have interacted surprisingly sporadically, aside from some pioneering work on HIV-1 and influenza. Bringing together the Expertise of bioinformaticians and virologists is crucial, since very specific but fundamental computational approaches are required for virus research, particularly in an era of big data. Collaboration between virologists and bioinformaticians is necessary to improve existing analytical tools, cloud-based systems, computational resources, data sharing approaches, new diagnostic tools, and bioinformatic training. Here, we highlight current progress and discuss potential avenues for future developments in this promising era of virus bioinformatics. We end by presenting an overview of current technologies, and by outlining some of the Major challenges and Advantages that bioinformatics will bring to the field of virology.