4,597 research outputs found
Metagenome Survey of a Multispecies and Alga-Associated Biofilm Revealed Key Elements of Bacterial-Algal Interactions in Photobioreactors
No full textPhotobioreactors (PBRs) are very attractive for sunlight-driven production of biofuels and capturing of anthropogenic CO2. One major problem associated with PBRs however, is that the bacteria usually associated with microalgae in nonaxenic cultures can lead to biofouling and thereby affect algal productivity. Here, we report on a phylogenetic, metagenome, and functional analysis of a mixed-species bacterial biofilm associated with the microalgae Chlorella vulgaris and Scenedesmus obliquus in a PBR. The biofilm diversity and population dynamics were examined through 16S rRNA phylogeny. Overall, the diversity was rather limited, with approximately 30 bacterial species associated with the algae. The majority of the observed microorganisms were affiliated with Alphaproteobacteria, Betaproteobacteria, and Bacteroidetes. A combined approach of sequencing via GS FLX Titanium from Roche and HiSeq 2000 from Illumina resulted in the overall production of 350 Mbp of sequenced DNA, 165 Mbp of which was assembled in larger contigs with a maximum size of 0.2 Mbp. A KEGG pathway analysis suggested high metabolic diversity with respect to the use of polymers and aromatic and nonaromatic compounds. Genes associated with the biosynthesis of essential B vitamins were highly redundant and functional. Moreover, a relatively high number of predicted and functional lipase and esterase genes indicated that the alga-associated bacteria are possibly a major sink for lipids and fatty acids produced by the microalgae. This is the first metagenome study of microalga- and PBR-associated biofilm bacteria, and it gives new clues for improved biofuel production in PBRs
Environmental detection of octahaem cytochromechydroxylamine/hydrazine oxidoreductase genes of aerobic and anaerobic ammonium-oxidizing bacteria
No full textBacterial aerobic ammonium oxidation and anaerobic ammonium oxidation (anammox) are important processes in the global nitrogen cycle. Key enzymes in both processes are the octahaem cytochrome c (OCC) proteins, hydroxylamine oxidoreductase (HAO) of aerobic ammonium-oxidizing bacteria (AOB), which catalyses the oxidation of hydroxylamine to nitrite, and hydrazine oxidoreductase (HZO) of anammox bacteria, which converts hydrazine to N(2). While the genomes of AOB encode up to three nearly identical copies of hao operons, genome analysis of Candidatus'Kuenenia stuttgartiensis' showed eight highly divergent octahaem protein coding regions as possible candidates for the HZO. Based on their phylogenetic relationship and biochemical characteristics, the sequences of these eight gene products grouped in three clusters. Degenerate primers were designed on the basis of available gene sequences with the aim to detect hao and hzo genes in various ecosystems. The hao primer pairs amplified gene fragments from 738 to 1172 bp and the hzo primer pairs amplified gene fragments from 289 to 876 bp in length, when tested on genomic DNA isolated from a variety of AOB and anammox bacteria. A selection of these primer pairs was also used successfully to amplify and analyse the hao and hzo genes in community DNA isolated from different ecosystems harbouring both AOB and anammox bacteria. We propose that OCC protein-encoding genes are suitable targets for molecular ecological studies on both aerobic and anaerobic ammonium-oxidizing bacteria
Stylos kai edraiōma tēs ekklēsias, sive, Dissertatio de iustificatione hominis
No full textquam ... sub praesidio ... Ioh. Henrici Heideggeri ... placido eruditorum examini subiicit Andreas Steinerus, Vitod. author & respondens, ad diem Octobris loco horisque solitisDiss. Hohe Schule Zürich, 167
Author: Andreas Johannis Prytz
No full textAn edition of the consecration sermons in Gothenburg Cathedral 1633 by Superintendent Andreas Johannis Prytz, with introductory comments. The first sermon deals with the need for Church buildings, the second with the consecration of a new Church
We must combine conservation of nature with benefits to society. Interview by Gaby Allheilig with Andreas Heinimann on IPBES' Global Assessment Report on Biodiversity and Ecosystem Services
No full textOn 6 May 2019, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) presented its report on the state of biodiversity and ecosystem services worldwide. The first such assessment since 2005, it concludes that biodiversity and ecosystem loss has reached the point where it threatens human well-being. The researchers involved recommend several urgent measures to political decision-makers. Andreas Heinimann of CDE was the one Swiss scientist who worked as a lead author on a chapter of the report
To athanaton tēs psychēs, sive, Dissertatio de animae immortalitate, ex naturae & sanae rationis lumine demonstrata
No full textquam ... sub praesidio ... Iohannis Lavateri ... publicae ac placidae disquisitioni submittit Andreas Steinerus, Vitod. author & respondens ...Dedikation an Johannes Lavater, Jacob Meyer, Joh. Jacob Schaedler und Jacob Hegner auf dem Titelbl. versoDiss. Hohe Schule Zürich, 167
Family Virtues and Social Critique: Andreas Latzko’s Anti-War Prose (1917-1918)
No full textBetween 1917 and 1918, the Austro-Hungarian author Andreas Latzko (1876-1943) wrote three separate publications against the Great War: Menschen im Krieg (1917), Friedensgericht (1918), and Der letzte Mann (published 1919). Literary historians tend to bypass these works, and the few who note them chiefly focus on the best-selling novella cycle Menschen im Krieg (1917). It is usually presented as an example of expressionist political prose, or as a mixture of social satire and aesthetic shock-tactics that chiefly remains indebted to realist traditions, albeit with occasional incursions into expressionistic styles..
Short laws for finite groups and residual finiteness growth
No full text We prove that for every n ∈ N n \in \mathbb {N} and δ > 0 \delta >0 there exists a word w n ∈ F 2 w_n \in F_2 of length O ( n 2 / 3 log ( n ) 3 + δ ) O(n^{2/3} \log (n)^{3+\delta }) which is a law for every finite group of order at most n n . This improves upon the main result of Andreas Thom [Israel J. Math. 219 (2017), pp. 469–478] by the second named author. As an application we prove a new lower bound on the residual finiteness growth of non-abelian free groups. </p
Investigations into structure and function of the polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis biofilms
No full textDas interzelluläre Polysaccharid-Adhäsin (PIA) von S.epidermidis ist ein essentieller Faktor für die Biofilmakkumulation, dem wichtigsten Virulenz Faktor im Kontext Fremdkörper-assoziierter Infektionen. Das PIA ist ein homopolymer aus ß-(1,6)-verknüpften N-Acetylglukosamin (GlcNAc) Einheiten. PIA ist ein zentraler Bestandteil der von S. epidermidis gebildeten extrazellulären Biofilmmatrix. Diese stabilisiert nicht nur die mehrlagige Biofilmarchitektur, sondern schützt S. epidermidis auch vor Angriffen durch das Immunsystem. Interessant ist Deacetylierung eines signifikanten Anteils der GlcNAc Reste, durch welche eine positive Nettoladung des Polymers resultiert, welche wiederum funktionell für die Biofilmbildung wie auch den PIA-vermittelten Schutz vor Effektoren der angeborenen Immunität notwendig ist (Vuong, 2004b). Die exakten Determinanten insbesondere der interzellulär adhäsiven Funktion von PIA sind jedoch bislang nicht bekannt.
Ein zentrales Ziel dieser Arbeit war es, durch die strukturelle Charakterisierung einer durch S. epidermidis 939 gebildeten hypothetischen serologischen Variante von PIA (PIAv) und den Abgleich mit PIA des S. epidermidis Referenzstamms 1457 Erkenntnisse über Struktur-Funktionsbeziehungen von PIA bei der S. epidermidis Biofilmbildung zu erhalten. S. epidermidis 939 zeichnet sich durch einen stark Biofilm-positiven Phänotyp bei nur schwacher Reaktivität mit einem spezifischen anti-PIA-Antiserum aus.
In phänotypischen Untersuchungen zur Stabilität des Biofilms gegenüber der Aktivität des PIA-spaltenden Enzyms DspB und Trypsin konnte gezeigt werden, dass bei S. epidermidis 939 wie auch S. epidermidis 1457 PIA oder ein nahe verwandetes Molekül funktionell an der Ausprägung eines biofilmpositiven Phänotyps ist. Durch die serologische Charakterisierung von S. carnosus TM300 nach in trans Expression von icaADBC des Stamms 1457 oder 939 kann gezeigt werden, dass Punktmutationen in icaA des Stamms 939 keinen Einfluss auf die Substratspezifität der hier kodierten N-Acetyglukosaminyltransfrase haben. Somit werden mögliche Modifikationen von PIA des Stamms 939 sekundär in das Molekül eingeführt.
Durch die Optimierung von Wachstumsbedingungen war es möglich, relevante Mengen extrazellulärer Biofilmmatrix des Stamms 939 zu gewinnen und deren Bestandteile durch GPC und AEC weiter aufzureinigen. Das komplexe Stoffgemisch der extrazellulären Biofilmmatrix der Stämme S. epidermidis 1457 und 939 weisen in der Gelpermeationschromatographie das gleiche Elutionsverhalten auf. In der Anionenaustauschchromatographie jedoch lässt sich das durch GPC gewonnene Material des Stamms 939 in drei immunreaktive peaks A-C trennen, bei S. epidermidis 1457 konnten hingegen nur peaks A und B nachgewiesen werden. Dabei handelt es sich um eine neutrale (A), eine schwach anionische (B) und bei S. epidermidis 939 um eine stark anionische (C) Fraktion. Im peak C kann, trotz der Immunoreaktivität mit anti-PIA-Antiserum, nicht wie bei peak A und B Hexosamin durch biochemische Verfahren dargestellt werden. Bei peak A handelt es sich bei S. epidermidis 939 wie auch 1457 um PIA. Die strukturelle Analyse von peak B zeigt keinen wesentlichen Unterschied zwischen S. epidermidis 939 und 1457, bei den isolierten Strukturen handelt es sich um die wall teichoic acid (WTA), jedoch nicht wie erwartet um ß-(1,6)-N-Acetylglukosamin. Die strukturelle Analyse des peaks C identifizierte Lipoteichonsäure (LTA) als zusätzliche Komponente im Biofilmmatrixextrakt von S. epidermidis 939.
Die Ergebnisse zeigen, dass offensichtlich S. epidermidis 939 wie auch 1457 PIA bildet, welches sich hinsichtlich seiner Eigenschaften in GPC und AEC nicht von PIA des Stamms 1457 unterscheidet. Die Unterschiede in der Zusammensetzung der Biofilmmatrix zwischen S. epidermidis 939 und 1457 könnten die Beobachtung eines stark biofilmpositiven Phänotyps trotz geringer PIA-Synthese bei S. epidermidis erklären.
Durch den Einsatz des gelfiltrierten PIAv als Ligand im „phage-display“ System ist neben verschiedenen Proteinen ein Fragment des YpfP Proteins identifiziert worden. Eine Diacylglycerol Glucosyltransferase, die für die Biosynthese von Glykolipid der LTA verantwortlich ist. Des weiteren ist das Fragment eines Oberflächenproteins, Embp identifiziert worden. Embp ist an der Entstehung von S. epidermidis Biofilmen beteiligt und besitzt eine FIVAR (found in various architectures) Domäne, die in anderen Organismen N-Acetylglukosamin-bindende Aktivität aufweist.
Die hier vorgestellten Ergebnisse motivieren einer weitere Analyse der Wechselwirkung zwischen Teichonsäuren und PIA. Außerdem wird der Hinweis auf eine potentielle Verbindung von Embp und PIA gestützt.The intercellular polysaccharid adhesin (PIA) from S. epidermidis is an essential factor for biofilmaccumulation, the most important virulence factor in the context of device-associated infections. PIA is a linear homoglycan, consisting of ß-(1,6)-linked N-acetylglucosamin (GlcNAc) residues. This carbohydrate is the central component of the extracellular produced biofilmmatrix, synthesized by S. epidermidis. PIA not only stabilizes the multilayered biofilmarchitecture, but it also defends S. epidermidis from immune invasion. What is interesting is the deacetylation of a significant rate of the GlcNAc moiety, which results in a positive charge of the polymer, which is necessary for functional biofilm formation, as well as PIA-dependent protection from innate immunity (Vuong, 2004b). At the moment, an exact determination of, above all, the intercellular adhesive function of PIA is completely unknown.
In this study, the main aim was to gain information about the structure-function-relation of PIA in biofilm formation via the structural characterization of a hypothetical serological variant of PIA (PIAv) produced by S. epidermidis 939 and a comparison with PIA from the reference strain S. epidermidis 1457. S. epidermidis 939 is characterized by a strong biofilm-positive phenotype with poor reactivity to the specific anti-PIA-antiserum.
Analysis of the stability of the biofilm compared with the PIA-cleaving enzyme DspB and Trypsin showed that PIA from S. epidermidis 939 and 1457 or a closely related molecule is functionally involved in a biofilm-positive phenotype. By means of a serological characterization of S. carnosus TM300, in accordance with the trans expression of icaADBC from strain 1457 or 939, it can be shown that punctual mutations in the space of icaA from 939 have no influence on the substrate specificity of the N-acetylglucosamin transferase coded here. In conclusion, all PIA modifications must be a secondary process. By optimizing the growth conditions, it was possible to extract relevant quantities of extracellular biofilmmatrix of the strain 939 and to further purify their constituents with GPC and AEC. The extract of S. epidermidis 1457 and 939 had the same behaviour in elution at the GPC. However, AEC purification separates GPC-eluate from S. epidermidis 939 into three immunoreactive, detectable peaks A-C, whereas for S. epidermidis 1457 it only displays peaks A and B. These refer to a neutral (A), a poor anionic (B) and, for S. epidermidis 939, a strong anionic (C) fraction. Unlike in peak A and peak B, hexosamine was not detectable by biochemical methods in peak C. Peak A applies to S. epidermidis 939 as well as 1457 PIA. There was basically no difference in the structural analysis of peak B between S. epidermidis 939 and 1457; although the isolated structures referred to wall teichoic acid (WTA), unlike the ß-(1,6)-linked N-acetylglucosamin, as expected. The structural analysis of peak C identified lipoteichoic acid (LTA) as an added component in the biofilmmatrixextract of S. epidermidis 939.
These results clearly showed that S. epidermidis 939 as well as 1457 synthesize PIA, without characteristic differences regarding the purification by GPC and AEC. Maybe this is an explanation for the observance of a strong biofilm-positive phenotype in spite of less PIA synthesis.
A fragment of YpfP protein, among others, was found by phage display screening with PIAv as ligand. The glycolipid biosynthesis from LTA takes place against this glycolipid diacylglycerol glucosyltransferase. Furthermore, an Embp surfaceprotein fragment was isolated. Embp is involved in S. epidermidis biofilm development and offers a FIVAR (found in various architectures) domain, which in other organisms exhibits binding activity to N-acetylglucosamin.
The results presented here motivate further analysis of the relationship between teichoic acid and PIA. Moreover, they support indications to a potential connection between Embp and PIA
Value quantification
No full textThis chapter explores the concept and practice of value quantification, emphasizing its crucial role in effectively communicating product offerings in industrial markets. Rather than relying solely on product characteristics, successful sales strategies involve translating unique selling points into quantifiable customer-specific economic value. The chapter synthesizes existing marketing and pricing literature, presenting a comprehensive model that categorizes benefits and sacrifices into quantitative and qualitative dimensions relevant to both B2B and B2C contexts. The author delineates a systematic approach for quantifying customer value, highlighting practical methodologies such as economic value analysis and conjoint analysis. Furthermore, the chapter underscores the managerial implications of value quantification, including enhanced pricing strategies, improved negotiation positions, reduced discounting, and performance-based pricing opportunities. Through detailed frameworks and real-world examples, the chapter provides actionable insights for effectively leveraging quantified value to gain competitive advantage and drive customer purchasing decisions
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