Post-pyrolysis treatments of biochars from sewage sludge and A. mearnsii for ammonia (NH4-n) recovery

NH4-N-loaded biochars are suitable candidates for soil amendment and fertilization. Sewage sludge-based biochar and biochar from the invasive species black wattle were used as sorbents for the adsorption of ammonia from a concentrated solution to mimic the wastewater treatment plant reject water stream. To increase ammonium recovery efficiency, two post-pyrolysis activation techniques were compared: steam activation and hydrogen peroxide treatment. It was found that the success of the treatment options was material dependent; therefore, post-pyrolysis treatments will require optimization for different applications based on feedstock. A simplified version of an adsorption process simulated in Aspen Tech predicts that NH4-N may be recovered at an energy cost lower than that of the Haber-Bosch process for black wattle biochar yields of below 19.5%. The biooil and syngas produced during pyrolysis can be used to lessen the energy requirements of the process, so that the solid portion may be utilized as an adsorbent and soil fertilizer. The energy-based sustainability of this technology warrants a more in-depth investigation for evaluation of the techno-economic feasibility for this class of loaded sorbents, and whether this method of nitrogen capture from wastewater is a suitable replacement of the costly Haber-Bosch process.http://www.elsevier.com/locate/apenergyhj2020Chemical Engineerin

MEDELLER: homology-based coordinate generation for membrane proteins

Motivation: Membrane proteins (MPs) are important drug targets but knowledge of their exact structure is limited to relatively few examples. Existing homology-based structure prediction methods are designed for globular, water-soluble proteins. However, we are now beginning to have enough MP structures to justify the development of a homology-based approach specifically for them

Cyclophilin A interacts with diverse lentiviral capsids

BACKGROUND: The capsid (CA) protein of HIV-1 binds with high affinity to the host protein cyclophilin A (CypA). This binding positively affects some early stage of the viral life-cycle because prevention of binding either by drugs that occupy that active site of cyclophilin A, by mutation in HIV-1 CA, or RNAi that knocks down intracellular CypA level diminishes viral infectivity. The closely related lentivirus, SIVcpz also binds CypA, but it was thought that this interaction was limited to the HIV-1/SIVcpz lineage because other retroviruses failed to interact with CypA in a yeast two-hybrid assay. RESULTS: We find that diverse lentiviruses, FIV and SIVagmTAN also bind to CypA. Mutagenesis of FIV CA showed that an amino acid that is in a homologous position to the proline at amino acid 90 of HIV-1 CA is essential for FIV interactions with CypA. CONCLUSION: These results demonstrate that CypA binding to lentiviruses is more widespread than previously thought and suggest that this interaction is evolutionarily important for lentiviral infection

Transcriptional Activity and Nuclear Localization of Cabut, the Drosophila Ortholog of Vertebrate TGF-β-Inducible Early-Response Gene (TIEG) Proteins

BackgroundCabut (Cbt) is a C2H2-class zinc finger transcription factor involved in embryonic dorsal closure, epithelial regeneration and other developmental processes in Drosophila melanogaster. Cbt orthologs have been identified in other Drosophila species and insects as well as in vertebrates. Indeed, Cbt is the Drosophila ortholog of the group of vertebrate proteins encoded by the TGF-ß-inducible early-response genes (TIEGs), which belong to Sp1-like/Krüppel-like family of transcription factors. Several functional domains involved in transcriptional control and subcellular localization have been identified in the vertebrate TIEGs. However, little is known of whether these domains and functions are also conserved in the Cbt protein.Methodology/Principal FindingsTo determine the transcriptional regulatory activity of the Drosophila Cbt protein, we performed Gal4-based luciferase assays in S2 cells and showed that Cbt is a transcriptional repressor and able to regulate its own expression. Truncated forms of Cbt were then generated to identify its functional domains. This analysis revealed a sequence similar to the mSin3A-interacting repressor domain found in vertebrate TIEGs, although located in a different part of the Cbt protein. Using β-Galactosidase and eGFP fusion proteins, we also showed that Cbt contains the bipartite nuclear localization signal (NLS) previously identified in TIEG proteins, although it is non-functional in insect cells. Instead, a monopartite NLS, located at the amino terminus of the protein and conserved across insects, is functional in Drosophila S2 and Spodoptera exigua Sec301 cells. Last but not least, genetic interaction and immunohistochemical assays suggested that Cbt nuclear import is mediated by Importin-α2.Conclusions/SignificanceOur results constitute the first characterization of the molecular mechanisms of Cbt-mediated transcriptional control as well as of Cbt nuclear import, and demonstrate the existence of similarities and differences in both aspects of Cbt function between the insect and the vertebrate TIEG proteins

The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

Scanning Tunneling Microscopy Studies on the Adsorption of Oxygen and Gold on the Rhenium (10-10)-Surface

Gold/Rhenium(10-10): In der vorgelegten Arbeit konnte die Existenz verschiedener (1xn)-Goldphasen auf der Rheniumoberfläche beginnend mit der (1x3)-Phase bei niedrigen Bedeckungen über eine (1x4)-, (1x5)- und (1x6)-Phase bei mittleren und einer (1x8)-Phase bei hohen Bedeckungen verifiziert und deren Struktur aufgeklärt werden. Für niedrige Bedeckungen unterhalb der Bildung der (1x3)-Phase konnte zudem durch RTM erstmals das Wachstum von pseudomorphen, rechteckigen und entlang der Hauptkristallachsen orientierten Bilageninseln nachgewiesen werden. Für Bedeckungen von 2 ML wurde die schon in früheren Arbeiten vermutete Bildung einer pseudomorphen Bilage bestätigt. Die danach auftretende (1x8)-Phase ist erstaunlich stabil, bis hin zu sehr hohen Bedeckungen von 64 ML. Weiterhin konnte ein schon in früheren Arbeiten beschriebener Alterungsprozess des Goldes auf der Oberfläche bestätigt werden. Mit der Zeit erfolgt sowohl durch attraktive Wechselwirkungen des Goldes als auch durch den von Kohlenmonoxid ausgeübten Spreitungsdruck ein Zusammenwachsen des Goldes auf der Oberfläche zu geschlossenen Bilagen- Arealen. Sauerstoff/Rhenium(10-10): Bezüglich der Sauerstoffphasen auf der Rhenium-oberfläche wurde für die c(2x4)-Phase ein bereits früher als plausibel vorgeschlagenes Strukturmodell bestätigt, bei welcher der Sauerstoff auf einem dreifachen hcp-artigen Adsorptionsplatz mit Cs-Symmetrie sitzt. Höhere Sauerstoffbedeckungen führen zu den bekannten (1x5)-, (1x4)- und (1x3)-Phasen. Unter Einbeziehung von Rechnungen von Kaghazchi und Jacob und mit Hilfe einer detaillierten Auswertung der RTM-Bilder ließ sich ein Bildungsprinzip ableiten, wonach alle Rekonstruktionen einem „double-missing-row“-Modell zu folgen scheinen. Vor allem während der Bildung der (1x5)-Phase, bei der erstmals eine massive Rekonstruktion der Rheniumoberfläche eintritt, erscheinen im Rastertunnelmikroskop mehrere Atome große kugelförmige Aggregate, die möglicherweise mit der Bildung von Rheniumoxiden in Zusammenhang stehen. Gold/Sauerstoff/Rhenium(10-10): Für Gold, das auf eine mit der (1x3)-Sauerstoff-Sättigungsphase bedeckte Rheniumoberfläche aufgebracht wurde, zeigt sich schon bei niedrigen Bedeckungen ein clusterartiges Volmer-Weber-Wachstum. Dieser Wachstumsmodus setzt sich bei Raumtemperatur zu höheren Bedeckungen hin derart fort, dass die Oberfläche nunmehr von großen Clustern übersät ist, die jedoch nicht koagulieren. Tempern setzt dagegen massive Gold-Diffusion in Gang, und es bilden sich entlang der [1-210]-Richtung längere Goldzylinder mit elliptischem Querschnitt. Adsorption von Gold auf der mit weniger Sauerstoff bedeckten Rheniumoberfläche führt bei niedrigem Goldangebot zunächst zum Wachstum von schmalen Goldketten, die bevorzugt an Stufenkanten orientiert sind und diese regelrecht dekorieren. Erst bei deutlich höheren Goldbedeckungen kommt es neben der Aggregation vereinzelter größerer Goldcluster zur Bildung von (1x3)-Phasenarealen.Gold/Rhenium(10-10): In the presented work different (1xn)-gold phases on the rhenium surface were confirmed. With increasing coverage, a (1x3)-phase is followed by (1x4)-, (1x5)- and (1x6)-phases at medium coverage, until at exact one bilayer a pseudomorphic (1x1) phase forms. Our STM studies show that this phase exists only within a narrow coverage range; as soon as the Au coverage exceeds the bilayer concentration, a (1x8) structure forms and surprisingly persists up to Au coverages of ~ 32 bilayers. All phases were resolved in real space by careful STM experiments. In the very low coverage regime individual separated pseudomorphic (1x1) bilayer islands of rectangular shape form that are aligned to the main Re crystal axes. Another previously assumed and discussed phenomenon could be confirmed and disentangled by directly tracking time-dependent Au diffusion and aging effects by means of STM. Responsible for the coalescence of the Au atoms to closed bilayer islands are lateral Au – Au interactions and gradually co-adsorbing CO molecules which exert a two- dimensional spreading pressure. Oxygen/Rhenium(10-10): For most oxygen phases previously reported the real-space structure could be resolved for the first time here. For the initial oxygen-induced c(2x4)-phase a previously proposed structure model could be proven, in which the oxygen atom is located in a threefold hcp-like site with Cs-symmetry. Higher oxygen coverages lead to the known (1x5)-, (1x4)- and (1x3) LEED phases. Taking into account recent calculations by Kaghazchi and Jacob and scrutinizing the details of the STM images we succeeded in analyzing the reconstruction as being of the double- missing-row type. Especially during the formation of the (1x5)-phase, where a massive reconstruction of the rhenium surface sets in for the first time, globule aggregates of regular spherical shape appear inside the furrows of the reconstructed surface which potentially could be connected with the formation of rhenium oxide complexes. Gold/Oxygen/Rhenium(10-10): If the Re surface is pre-covered with the (1x3)-2O oxygen saturation phase even at very low coverages the Au atoms coagulate to small clusters and exhibit a clear Volmer- Weber growth. At room temperature the respective cluster growth continues up to elevated coverages where the surface is cluttered with fairly large individual Au clusters that nevertheless do not coagulate. Only annealing induces massive gold diffusion resulting in the formation of distinct Au rolls or cylinders with an elliptical profile along [1-210]-direction. Turning to the interaction of gold on Re surface covered with less oxygen one now observes the growth of small gold chains, which preferably develop at edges and decorate these downright. It is not until remarkably higher gold coverages that the aggregation of scattered larger gold clusters occurs, along with the formation of areas of (1x3)-phase

Untersuchung und Optimierung des Biogasbildungspotentials der marinen Mikroalge Nannochloropsis salina\textit {Nannochloropsis salina}

Ziel der vorliegenden Dissertation war die Untersuchung und Optimierung des Biogasbildungspotentials der marinen Mikroalge $\textit {Nannochloropsis salina}$ im Rahmen von Batchversuchen und einer semi-kontinuierlichen Langzeitstudie im Vergleich zu Maissilage. Im Rahmen der Batchersuche wurden der Salzgehalt, der robuste Zellwandaufbau und die unausgeglichene Nähstoffzusammensetzung der Algenbiomasse als limitierende Faktoren in der Vergärung der Mikroalge identifiziert. In semi-kontinuierlichen Langzeitversuchen wurde in der Monovergärung der Algenbiomasse eine konstante Zunahme des Ammoniumgehaltes und der Leitfähigkeit beobachtet, die in einer Störung des Prozessgleichgewichtes durch Akkumulierung von flüchtigen organischen Säuren resultierte. Durch Adaption der mikrobiellen Biozönose an die veränderten Bedingungen konnte zum Ende der Versuchsreihe ein stabiler Abbau der Algenbiomasse mit vermindertem Abbaugrad (ca. 50%) erreicht werden