Search results for "Bios"
showing 10 items of 2557 documents
Combined NC-AFM and DFT study of the adsorption geometry of trimesic acid on rutile TiO2(110)
2010
The adsorption behavior of trimesic acid (TMA) on rutile TiO(2)(110) is studied by means of non-contact atomic force microscopy (NC-AFM) and density-functional theory (DFT). Upon low-coverage adsorption at room temperature, NC-AFM imaging reveals individual molecules, centered above the surface titanium rows. Based on the NC-AFM results alone it is difficult to deduce whether the molecules are lying flat or standing upright on the surface. To elucidate the detailed adsorption geometry, we perform DFT calculations, considering a large number of different adsorption positions. Our DFT calculations suggest that single TMA molecules adsorb with the benzene ring parallel to the surface plane. In…
RPB1 as a marker gene to analyze communities of arbuscular mycorrhizal fungi (Glomeromycota)
2014
The influence of agricultural practice on the diversity of Arbuscular mycorrhizal fungi (AMF, Glomeromycota) continues to be an important research question as these mutualistic symbionts are known to improve plant growth and soil quality. To this day, studies of community diversity in AMF have exclusively been based on nuclear ribosomal gene regions, such as the small and large subunits and the ITS region. In the Glomeromycota, these regions show high intra-organism polymorphism, which can seriously complicate interpretation of diversity data. We chose the rpb1 gene as an alternative marker as this putative single-copy gene has been shown to be monomorphic within fungal isolates but shows a…
The Administration of Escherichia coli Nissle 1917 Ameliorates Development of DSS-Induced Colitis in Mice
2018
The beneficial effects of probiotics on immune-based pathologies such as inflammatory bowel disease (IBD) have been well reported. However, their exact mechanisms have not been fully elucidated. Few studies have focused on the impact of probiotics on the composition of the colonic microbiota. The aim of the present study was to correlate the intestinal anti-inflammatory activity of the probiotic Escherichia coli Nissle 1917 (EcN) in the dextran sodium sulfate (DSS) model of mouse colitis with the changes induced in colonic microbiota populations. EcN prevented the DSSinduced colonic damage, as evidenced by lower disease activity index (DAI) values and colonic weight/length ratio, when compa…
Variability of the human gut microbiota in space, time, and associated with the irritable bowel syndrome
2013
Esta tesis doctoral se centra en el estudio de una de las comunidades microbianas más complejas y de mayor interés biomédico: la microbiota asociada al intestino distal de humanos. El objetivo principal ha sido estudiar las alteraciones potenciales de la microbiota intestinal en relación con el síndrome del intestino irritable (SII), el desorden funcional del tracto gastrointestinal más común en sociedades occidentales. Nuestra aproximación forma parte de una visión actual sobre las relaciones entre microorganismos y hospedadores que trasciende la clásica y estrecha mirada sobre patógenos concretos y enfermedades infecciosas y la desplaza hacia una concepción más de conjunto, que valora los…
MEP metaboliskā ceļa matemātiskā modeļa izveide izoprēna un cis-abienola ražošanai Tāla sīkplikstiņā
2018
Darbā apskatīta sistēmbioloģijas pieeja augu biotehnoloģijai, tās nozīme un priekšrocības eksperimentālo un modelēšanas metožu apvienošanai. Šī darba ietvaros izveidots matemātiskais modelis MEP metaboliskā ceļa un izoprenoīdu prekursoru sintēzes kinētikai tāla sīkplikstiņa savvaļas formā ar tālāko mērķi to izmantot izoprēna un cis-abienola biosintēzes ceļu optimizācijai. Darba ietvaros tika veikta parametru novērtēšana, stacionārā stāvokļa noteikšana un parametru jutības analīze, pielāgojot modeļa darbību eksperimentālajiem datiem. Darba ietvaros izmēģinātas iespējas samazināt parametru novērtēšanas risinājumu telpu, aprēķinot bioloģiski atbilstošas robežvērtības un genoma mēroga stehiomet…
Removal of Cu(II) and Pb(II) from aqueous solutions by lacit acid bacteria
2015
Celem pracy było porównanie zdolności usuwania Cu(II) i Pb(II) z roztworu wodnego przez bakterie kwasu mlekowego (LAB). Badano wpływ różnych parametrów, tj. stężenia jonów metali, pH i czas kontaktu, na proces usuwania jonów miedzi i ołowiu. Do opisu izoterm adsorpcji jonów metali przez biomasę LAB zastosowano modele Langmuira i Freundlicha. Uzyskane dane doświadczalne były lepiej dopasowane do modelu Langmuira niż Freundlicha. Sorbent wykazał maksymalną zdolność sorpcyjną, wynoszącą 11,07 i 10.51 mg · g–1 odpowiednio dla jonów Cu(II) i Pb(II). Optymalne warunki biosorpcji obu jonów metali wynosiły: pH 6,0 i czas równowagi 40 minut. Omówiono również udział grup funkcyjnych na powierzchni bi…
Interkingdom Gut Microbiome and Resistome of the Cockroach Blattella germanica
2021
Cockroaches are intriguing animals with two coexisting symbiotic systems, an endosymbiont in the fat body, involved in nitrogen metabolism, and a gut microbiome whose diversity, complexity, role, and developmental dynamics have not been fully elucidated. In this work, we present a metagenomic approach to study Blattella germanica populations not treated, treated with kanamycin, and recovered after treatment, both naturally and by adding feces to the diet, with the aim of better understanding the structure and function of its gut microbiome along the development as well as the characterization of its resistome.
The toughest animals of the Earth versus global warming: Effects of long-term experimental warming on tardigrade community structure of a temperate d…
2021
Abstract Understanding how different taxa respond to global warming is essential for predicting future changes and elaborating strategies to buffer them. Tardigrades are well known for their ability to survive environmental stressors, such as drying and freezing, by undergoing cryptobiosis and rapidly recovering their metabolic function after stressors cease. Determining the extent to which animals that undergo cryptobiosis are affected by environmental warming will help to understand the real magnitude climate change will have on these organisms. Here, we report on the responses of tardigrades within a five‐year‐long, field‐based artificial warming experiment, which consisted of 12 open‐to…
Determination of sorption properties of heavy metals in various biosorbents
2018
Various techniques of determination of properties of physicochemical processes of heavy metal sorption in biosorbents were analysed. The methods of preparing and storing samples, conditions of experiment performance, as well as the methods of data interpretation were discussed. Two procedures of study were analysed: (1) in the static system of biosorbent-solution contact and (2) in the system of dynamic flow of solution. Copper cation sorption was studied. The effect of consecutive stages of the study on the quality of final results was shown. A high degree of uncertainty of the sorption capacity assessment was reported, which was dependent on the manner of conducting the study. The applica…
Negative impact of freeze–thaw cycles on the survival of tardigrades
2023
Global warming effects in temperate and polar regions include higher average temperatures and a decrease in snow cover, which together lead to an increase in the number of freeze–thaw cycles (FTC). These changes could affect the fitness of both terrestrial and aquatic species. In this study, we tested how tardigrades, ubiquitous microscopic invertebrates, face FTC. Tardigrades are amongst the most resistant animals to unfavorable conditions, including long and deep freezing periods, and are an emerging model group for invertebrate ecology and evolution. We used 12 populations of tardigrades, representing different families within order Parachela, inhabiting different ecosystems (glaciers, s…