Extremophiles in soil communities of former copper mining sites of the East Harz region (Germany) reflected by re-analyzed 16S rRNA data. - In: Microorganisms, ISSN 2076-2607, Bd. 9 (2021), 7, 1422, insges. 16 S.
The east and southeast rim of Harz mountains (Germany) are marked by a high density of former copper mining places dating back from the late 20th century to the middle age. A set of 18 soil samples from pre- and early industrial mining places and one sample from an industrial mine dump have been selected for investigation by 16S rRNA and compared with six samples from non-mining areas. Although most of the soil samples from the old mines show pH values around 7, RNA profiling reflects many operational taxonomical units (OTUs) belonging to acidophilic genera. For some of these OTUs, similarities were found with their abundances in the comparative samples, while others show significant differences. In addition to pH-dependent bacteria, thermophilic, psychrophilic, and halophilic types were observed. Among these OTUs, several DNA sequences are related to bacteria which are reported to show the ability to metabolize special substrates. Some OTUs absent in comparative samples from limestone substrates, among them Thaumarchaeota were present in the soil group from ancient mines with pH > 7. In contrast, acidophilic types have been found in a sample from a copper slag deposit, e.g., the polymer degrading bacterium Granulicella and Acidicaldus, which is thermophilic, too. Soil samples of the group of pre-industrial mines supplied some less abundant, interesting OTUs as the polymer-degrading Povalibacter and the halophilic Lewinella and Halobacteriovorax. A particularly high number of bacteria (OTUs) which had not been detected in other samples were found at an industrial copper mine dump, among them many halophilic and psychrophilic types. In summary, the results show that soil samples from the ancient copper mining places contain soil bacterial communities that could be a promising source in the search for microorganisms with valuable metabolic capabilities.
https://doi.org/10.3390/microorganisms9071422
Protective effect of water-soluble C60 fullerene nanoparticles on the ischemia-reperfusion injury of the muscle soleus in rats. - In: International journal of molecular sciences, ISSN 1422-0067, Bd. 22 (2021), 13, 6812, S. 1-13
The biomechanical parameters of muscle soleus contraction in rats and their blood biochemical indicators after the intramuscular administration of water-soluble C60 fullerene at doses of 0.5, 1, and 2 mg/kg 1 h before the onset of muscle ischemia were investigated. In particular, changes in the contraction force of the ischemic muscle soleus, the integrated power of the muscle, the time to achieve the maximum force response, the dynamics of fatigue processes, and the parameters of the transition from dentate to smooth tetanus, levels of creatinine, creatine kinase, lactate and lactate dehydrogenase, and parameters of prooxidant-antioxidant balance (thiobarbituric acid reactive substances, hydrogen peroxide, and reduced glutathione and catalase) were analyzed. The positive therapeutic changes in the studied biomechanical and biochemical markers were revealed, which indicate the possibility of using water-soluble C60 fullerenes as effective prophylactic nanoagents to reduce the severity of pathological conditions of the muscular system caused by ischemic damage to skeletal muscles.
https://doi.org/10.3390/ijms22136812
Analysis of biomechanical parameters of muscle soleus contraction and blood biochemical parameters in rat with chronic glyphosate intoxication and therapeutic use of C60 fullerene. - In: International journal of molecular sciences, ISSN 1422-0067, Bd. 22 (2021), 9, 4977, S. 1-11
https://doi.org/10.3390/ijms22094977
Electrostatic control of Au nanorod formation in automated microsegmented flow synthesis. - In: ACS applied nano materials, ISSN 2574-0970, Bd. 4 (2021), 2, S. 1411-1419
An automated flow rate program was applied for the synthesis of gold nanorods of different aspect ratios dependent on a two-dimensional concentration space of reducing agent and additional silver ions. It was found a regular redshift of the spectral position of the electromagnetic in-axis resonance of metal nanorods with decreasing concentration of reducing agent and increasing concentration of silver ions. The increase of resonance wavelength is strongly correlated with the aspect ratio of the formed nanorods. The experimental results agree with an electrostatic model of self-polarization due to positive excess charge of the nanorods in the presence of CTAB and confirm the crucial role of electrostatic control in the formation of nonspherical and composed nanoparticles in general.
https://doi.org/10.1021/acsanm.0c02941
Reclassification of Haloactinobacterium glacieicola as Occultella glacieicola gen. nov., comb. nov., of Haloactinobacterium album as Ruania alba comb. nov, with an emended description of the genus Ruania, recognition that the genus names Haloactinobacterium and Ruania are heterotypic synonyms and description of Occultella aeris sp. nov., a halotolerant isolate from surface soil sampled at an ancient copper smelter. - In: International journal of systematic and evolutionary microbiology, ISSN 1466-5034, Bd. 71 (2021), 4, 004769
In the course of screening the surface soils of ancient copper mines and smelters (East Harz, Germany) an aerobic, non-motile and halotolerant actinobacterium forming small rods or cocci was isolated. The strain designated F300T developed creamy to yellow colonies on tryptone soy agar and grew optimally at 28 ˚C, pH 7-8 and with 0.5-2% (m/v) NaCl. Its peptidoglycan was of type A4α l-Lys-l-Glu (A11.54). The menaquinone profile was dominated by MK-8(II, III-H4) and contained minor amounts of MK-8(H2), MK-8(H6) and MK-9(H4). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, mono and diacylated phosphatidylinositol dimannosides, and components that were not fully characterized, including two phospholipids, two glycolipids and an uncharacterized lipid. Major whole-cell sugars were rhamnose and ribose. The fatty acid profile contained mainly iso and anteiso branched fatty acids (anteiso-C15:0, iso-C14:0) and aldehydes/dimethylacetals (i.e. not fatty acids). Sequence analysis of its genomic DNA and subsequent analysis of the data placed the isolate in the group currently defined by members of the genera Ruania and Haloactinobacterium (family Ruaniaceae , order Micrococcales ) as a sister taxon to the previously described species Haloactinobacterium glacieicola , sharing an average nucleotide identity and average amino acid identity values of 85.3 and 85.7%, respectively. Genotypic and chemotaxonomic analyses support the view that strain F300T (=DSM 108350T=CIP 111667T) is the type strain of a new genus and new species for which the name Occultella aeris gen. nov., sp. nov. is proposed. Based on revised chemotaxonomic and additional genome based data, it is necessary to discuss and evaluate the results in the light of the classification and nomenclature of members of the family Ruaniaceae , i.e. the genera Haloactinobacterium and Ruania . Consequently, the reclassification of Haloactinobacterium glacieicola as Occultella glacieicola comb. nov. and Haloactinobacterium album as Ruania alba comb. nov., with an emended description of the genus Ruania are proposed.,
https://doi.org/10.1099/ijsem.0.004769
Hierarchical assemblies of polymer particles through tailored interfaces and controllable interfacial interactions. - In: Advanced functional materials, ISSN 1616-3028, Bd. 31 (2021), 9, 2007407, insges. 22 S.
Hierarchical assembly architectures of functional polymer particles are promising because of their physicochemical and surface properties for multi-labeling and sensing to catalysis and biomedical applications. While polymer nanoparticles' interior is mainly made up of the cross-linked network, their surface can be tailored with soft, flexible, and responsive molecules and macromolecules as potential support for the controlled particulate assemblies. Molecular surfactants and polyelectrolytes as interfacial agents improve the stability of the nanoparticles whereas swellable and soft shell-like cross-linked polymeric layer at the interface can significantly enhance the uptake of guest nano-constituents during assemblies. Besides, layer-by-layer surface-functionalization holds the ability to provide a high variability in assembly architectures of different interfacial properties. Considering these aspects, various assembly architectures of polymer nanoparticles of tunable size, shapes, morphology, and tailored interfaces together with controllable interfacial interactions are constructed here. The microfluidic-mediated platform has been used for the synthesis of constituents polymer nanoparticles of various structural and interfacial properties, and their assemblies are conducted in batch or flow conditions. The assemblies presented in this progress report is divided into three main categories: cross-linked polymeric network's fusion-based self-assembly, electrostatic-driven assemblies, and assembly formed by encapsulating smaller nanoparticles into larger microparticles.
https://doi.org/10.1002/adfm.202007407
Tailored nanotopography of photocurable composites for control of cell migration. - In: RSC Advances, ISSN 2046-2069, Bd. 11 (2021), 8, S. 4286-4296
External mechanical stimuli represent elementary signals for living cells to adapt to their adjacent environment. These signals range from bulk material properties down to nanoscopic surface topography and trigger cell behaviour. Here, we present a novel approach to generate tailored surface roughnesses in the nanometer range to tune surface properties by particle size and volume ratio. Time-resolved local mean-squared displacement (LMSD) analysis of amoeboid cell migration reveals that nanorough surfaces alter effectively cell migration velocities and the active cell migration phases. Since the UV curable composite material is easy to fabricate and can be structured via different light based processes, it is possible to generate hierarchical 3D cell scaffolds for tissue engineering or lab-on-a-chip applications with adjustable surface roughness in the nanometre range.
https://doi.org/10.1039/D0RA06530G
In situ assembly of gold nanoparticles in the presence of poly-DADMAC resulting in hierarchical and highly fractal nanostructures. - In: Applied Sciences, ISSN 2076-3417, Bd. 11 (2021), 3, 1191, S. 1-13
The presence of the polycationic macromolecule poly(diallyldimethylammonium chloride) (poly-DADMAC) has a strong effect on the shape and size of colloidal gold nanoparticles formed by the reduction of tetrachloroauric acid with ascorbic acid in aqueous solution. It slows down nanoparticle growth and supports the formation of nonspherical, partially highly fractal and hierarchical nanoparticle shapes. Four structural levels have been recognized from the near-spherical gold nanoparticles in the lower nanometer range over compact aggregates in the midnanometer range and flower and star-like particles in the submicron range up to larger filamentous aggregates. High-contrast scanning electron microscope (SEM) images show that single gold nanoparticles and clusters of them are connected by bundles of macromolecules in large aggregates. The investigation showed that a large spectrum of different nanoparticle shapes and sizes can be accessed by tuning the poly-DADMAC concentrations and their ratio to other reactants. The nanoassemblies with a very high specific surface area might be of interest for SERS and heterogeneous catalysis.
https://doi.org/10.3390/app11031191
Fast reaction screening combining segmentet flow microfluidics and surface enhanced Raman spectroscopy. - In: 23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2019), (2020), S. 1368-1369
Salpetersäure zum Rauchen bringen. - In: Nachrichten aus der Chemie, ISSN 1868-0054, Bd. 68 (2020), 10, S. 20-22
Rauchende Salpetersäure ist im Handel nur hochrein zu kaufen und daher teuer - zu teuer für Hochschulpraktika. An der TU Ilmenau synthetisieren die Studierenden die HNO3 nun selbst als Praktikumsversuch und nutzen dafür historische Anleitungen.
https://doi.org/10.1002/nadc.20204101724