Mdm38 interacts with ribosomes and is a component of the mitochondrial protein export machinery

Saccharomyces cerevisiae Mdm38 and Ylh47 are homologues of human Letm1, a protein implicated in Wolf-Hirschhorn syndrome. We analyzed the function of Mdm38 and Ylh47 in yeast mitochondria to gain insight into the role of Letm1. We find that mdm38Δ mitochondria have reduced amounts of certain mitochondrially encoded proteins and low levels of complex III and IV and accumulate unassembled Atp6 of complex V of the respiratory chain. Mdm38 is especially required for efficient transport of Atp6 and cytochrome b across the inner membrane, whereas Ylh47 plays a minor role in this process. Both Mdm38 and Ylh47 form stable complexes with mitochondrial ribosomes, similar to what has been reported for Oxa1, a central component of the mitochondrial export machinery. Our results indicate that Mdm38 functions as a component of an Oxa1-independent insertion machinery in the inner membrane and that Mdm38 plays a critical role in the biogenesis of the respiratory chain by coupling ribosome function to protein transport across the inner membrane

Protection and consolidation of stone heritage by self-inoculation with indigenous carbonatogenic bacterial communities

Enhanced salt weathering resulting from global warming and increasing environmental pollution is endangering the survival of stone monuments and artworks. To mitigate the effects of these deleterious processes, numerous conservation treatments have been applied that, however, show limited efficacy. Here we present a novel, environmentally friendly, bacterial self-inoculation approach for the conservation of stone, based on the isolation of an indigenous community of carbonatogenic bacteria from salt damaged stone, followed by their culture and re-application back onto the same stone. This method results in an effective consolidation and protection due to the formation of an abundant and exceptionally strong hybrid cement consisting of nanostructured bacterial CaCO3 and bacterially derived organics, and the passivating effect of bacterial exopolymeric substances (EPS) covering the substrate. The fact that the isolated and identified bacterial community is common to many stone artworks may enable worldwide application of this novel conservation methodology.This work was supported by the Spanish Government (Grants MAT2012-37584, CGL2012-35992 and CGL2015-70642-R), the Junta de Andalucía through Proyecto de excelencia RNM-3493 and Project P11-RNM-7550, the Research Groups BIO 103 and RNM-179, and the University of Granada (Unidad Científica de Excelencia UCE-PP2016-05). Additional funds were provided by the Molecular Foundry (Lawrence Berkeley National Laboratory, LBNL, University of California, Berkeley, CA) for a research stay of M.S. (project #1451; User Agreement No. NPUSR009206)

Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada

Background: Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings: Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions: The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de Andalucía (Spain) and the “Fortalecimiento de la I+D+i” program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de Andalucía, as well as by the Spanish Government through “José Castillejo” program from the “Ministerio de Educación, Cultura y Deporte” (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant “Elise-Richter V194-B20”

Untersuchungen zur Biodeterioration von Sandsteinen unter besonderer Beruecksichtigung der chemoorganotrophen Bakterien

With appendixTIB: RN 5905(2275) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Coupling Liquid Chromatography to Mass Spectrometry, Infrared Spectroscopy and Nuclear Magnetic Resonance for the Identification of Reaction Products from α-Pinene Ozonolysis

Since the first reports about the "blue haze" phenomenon abobe forests it is known, that the emissions from plants, mostly isoprene, mono- and sequiterpenes, may have an impact on the formation of the secondary organic aerosols in the atmosphere. Some of the reaction products of the biogenic emissions with atmosphereic oxidantes (OH-radicals and ozone) have already been investigated. Unfortunately, due to the lack of synthetic standard compounds and the very similar structure of the products it is difficult to identify them. Therefore, we have used the detection capabilities of mass spectrometry (MS) together with infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR) to understand the gas phase reactions of a model compound, in this case α-pinene. Because of the complexity of the analytical approach of the low volatile reaction products, a separation with liquid chromatography (LC) ws necessary. The interface systems will be described and first results presented

Untersuchungen zur chemischen Zusammensetzung der organischen Komponente des troposphaerischen Aerosols AFS-Abschlussbericht

Although the knowledge about the significance of airborne particulate matter for the radiation balance of the atmosphere has increased during the last few years, several important aerosol formation mechanisms are still poorly understood. This is especially true for aerosols which are formed from volatile organic precursors from natural or anthropogenic sources (secondary organic aerosols). Therefore, the research project aimed on the development of a mass spectrometric real-time technique for the qualitative and quantitative investigations of the chemical composition of secondary organic aerosols, especially from the ozonolysis of monoterpenes (e.g. #alpha#-pinene, #beta#-pinene, sabinene, #DELTA#"3-carene, limonene). Using a modified atmospheric pressure chemical ionisation source (APCI), the formation of gas and particle phase products could be observed with a time resolution of about 1 second. The detection limit of the developed technique is about 100 ppt(v/v) in the positive ion mode. Based on the development of standard addition techniques, selected products were quantified in the gas and particle phase. Using isotopically labelled water also certain underlying reaction mechanisms were investigated. Another part of the project focused on the identification of low volatile reaction products by MS/MS-studies. These studies showed that the particle phase is mainly composed of several multifunctional carboxylic acids (dicarboxylic acids, oxo-carboxylic acids, hydroxy-carboxylic acids etc.). Finally, the APCI-studies gave robust evidences on the presence of strong intermolecular interactions between the different products. Since the experiments also showed a correlation between the intensity of product interactions (adduct formation) by hydrogen-bonding and new particle formation potential, the results of the project can be considered to provide an important contribution for an better understanding of nucleation events above forested areas. (orig.)Obwohl das Wissen um die Bedeutung von luftgetragenen Partikeln fuer die Strahlungsbilanz der Atmosphaere in den letzten Jahren zugenommen hat, sind eine Reihe von wichtigen Aerosolbildungsmechanismen bisher nur unzureichend untersucht worden. Dies gilt insbesondere fuer Aerosole, die aus fluechtigen organischen Vorlaeufern natuerlichen wie auch antrophogenen Ursprungs im Verlauf von troposphaerischen Oxidationsprozessen gebildet werden. Das Vorhaben umfasste daher die Entwicklung massenspektrometrischer Methoden fuer qualitative wie auch fuer quantitative Studien zur chemischen Zusammensetzung von sekundaeren organischen Aerosolen (SOA), insbesondere gebildet aus der Ozonolyse von Monoterpenen (z.B. #alpha#-Pinen, #beta#-Pinen, Sabinen, #DELTA#"3-Caren, Limonen). Mit Hilfe eines entwickelten On-line APCI-ITMS-Systems (atmospheric pressure chemical ionisation, APCI) konnte die Bildung von Gas- und Partikelphasenprodukten in Echtzeit (Zeitaufloesung #propor to#1 s) als Folge der Monoterpen-Ozonolyse beobachtet werden. Die Nachweisgrenze der Methode liegt bei ca. 100 ppt(v/v) im positiven Ionenmodus. Basierend auf der Entwicklung geeigneter Standardadditionsmethoden erfolgte auch die unmittelbare Quantifizierung ausgewaehlter Oxidationsprodukte in der Gas- und Partikelphase. Mittels isotopenmarkiertem Wasser (H_2"1"8O) wurden darueber hinaus einige zugrundeliegende Reaktionsmechanismen aufgedeckt. Ein weiterer Teil des Projektes konzentrierte sich auf die Charakterisierung insbesondere der schwerfluechtigen Aerosolkomponenten der Monoterpen-Ozonolyse mittels MS/MS-Studien. Diese Studien ergaben, dass eine Reihe von multifunktionellen Carbonsaeureprodukte signifikante Aerosolbestandteile repraesentieren (Dicarbonsaeuren, Oxocarbonsaeuren, Hydroxycarbonsaeuren etc.). Schliesslich ergaben die massenspektrometrischen Untersuchungen deutliche Hinweise auf starke intermolekulare Wechselwirkungen zwischen den einzelnen Produkten (Assoziatbildung). Da ausserdem ein Zusammenhang zwischen der Bildung dieser Assoziate und dem Potential der Vorlaeuferverbindungen zur Partikelneubildung gezeigt werden konnte, leisten die vorgestellten Projektresultate einen wichtigen Beitrag zur Erklaerung von Partikelneubildungsereignissen ueber bewaldeten Waldregionen. (orig.)SIGLEAvailable from TIB Hannover: F02B972+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman