• Energy Research
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The fast decay in PEM fuel cells of a highly active, high performance, but unstable Fe/N/C catalyst like our NC_Ar + NH3 follows a chemical, not an electrochemical, demetallation mechanism for its ORR active FeN4 sites in the catalyst micropores.

Global energy consumption has risen enormously over the past century due to population growth and increasing energy use per person. Industrial production consumes a significant portion of global energy resources. Thus, industrial sector’s investment in energy efficiency is critical to a sustainable future. For most global enterprises the consumption of energy and natural resources represents a major overhead and developing sustainable energy policies can represent a significant competitive advantage due to the growing price of energy and volatility of supply. This symbiotic relationship can lead to the mutual benefits of increasing industrial efficiency whilst allowing the transition to a sustainable renewables-based energy future and needs to be significantly harnessed. This paper describes a decision support framework to help industrial organisations make positive investment decisions on energy performance improvement projects.

Lipase‐catalyzed transesterification of triglycerides and alcohols to obtain biodiesel is an environmentally friendly and sustainable route for fuels production since, besides proceeding in mild reaction conditions, it allows for the use of low‐cost feedstocks that contain water and free fatty acids, for example non‐edible oils and waste oils. This review article reports recent advances in the field and focus in particular on a major issue in the enzymatic process, the inactivation of most lipases caused by methanol, the preferred acyl acceptor used for alcoholysis. The recent results about immobilization of enzymes on nano‐materials and the use of whole‐cell biocatalysts, as well as the use of cell‐surface display technologies and metabolic engineering strategies for microbial production of biodiesel are described. It is discussed also insight into the effects of methanol on lipases obtained by modeling approaches and report on studies aimed at mining novel alcohol stable enzymes or at improving robustness in existing ones by protein engineering.

Biotechnology can greatly improve the efficiency of forest tree breeding for the production of biomass, energy, and materials. However, EU regulations impede the market introduction of genetically modified (GM) trees so their socioeconomic and environmental benefits are not realized. European policy makers should concentrate on a science-based regulatory process.

Abstract BackgroundMicroorganisms in biogas reactors are essential for degradation of organic matter and methane production. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository.ResultsHere, 134 publicly available metagenomes derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different biogas bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth dynamics for microbes involved in different steps of the food chain. ConclusionsThe outcome of this study highlights a high flexibility of the biogas microbiome, allowing it to modify its composition and to adapt to the environmental conditions, including temperatures and a wide range of substrates. Our findings enhance our mechanistic understanding of the AD microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem.

Ethanol can be produced from biomass and as such is renewable, unlike petroleum-based fuel. Almost all gasoline cars can drive with fuel containing 10% ethanol (E10), flex-fuel cars can even use 85% ethanol (E85). Brazil and the USA already include 10-27% ethanol in their standard fuel by law. Most health effect studies on car emissions are however performed with diesel exhausts, and only few data exists for other fuels. In this work we investigated possible toxic effects of exhaust aerosols from ethanol-gasoline blends using a multi-cellular model of the human lung. A flex-fuel passenger car was driven on a chassis dynamometer and fueled with E10, E85, or pure gasoline (E0). Exhausts obtained from a steady state cycle were directly applied for 6h at a dilution of 1:10 onto a multi-cellular human lung model mimicking the bronchial compartment composed of human bronchial cells (16HBE14o-), supplemented with human monocyte-derived dendritic cells and monocyte-derived macrophages, cultured at the air-liquid interface. Biological endpoints were assessed after 6h post incubation and included cytotoxicity, pro-inflammation, oxidative stress, and DNA damage. Filtered air was applied to control cells in parallel to the different exhausts; for comparison an exposure to diesel exhaust was also included in the study. No differences were measured for the volatile compounds, i.e. CO, NOx, and T.HC for the different ethanol supplemented exhausts. Average particle number were 6×102 #/cm3 (E0), 1×105 #/cm3 (E10), 3×103 #/cm3 (E85), and 2.8×106 #/cm3 (diesel). In ethanol-gasoline exposure conditions no cytotoxicity and no morphological changes were observed in the lung cell cultures, in addition no oxidative stress - as analyzed with the glutathione assay - was measured. Gene expression analysis also shows no induction in any of the tested genes, including mRNA levels of genes related to oxidative stress and pro-inflammation, as well as indoleamine 2,3-dioxygenase 1 (IDO-1), transcription factor NFE2-related factor 2 (NFE2L2), and NAD(P)H dehydrogenase [quinone] 1 (NQO1). Finally, no DNA damage was observed with the OxyDNA assay. On the other hand, cell death, oxidative stress, as well as an increase in pro-inflammatory cytokines was observed for cells exposed to diesel exhaust, confirming the results of other studies and the applicability of our exposure system. In conclusion, the tested exhausts from a flex-fuel gasoline vehicle using different ethanol-gasoline blends did not induce adverse cell responses in this acute exposure. So far ethanol-gasoline blends can promptly be used, though further studies, e.g. chronic and in vivo studies, are needed.

Phycoerythrocyanin (PEC) is part of the light harvesting system of cyanobacteria. The PEC monomer contains one phycoviolobilin chromophore, which transfers excitation energy onto two phycocyanobilin chromophores. Many spectroscopical methods have been used in the past to study the bulk properties of PEC. These methods average over many molecules. Therefore, differences in the behavior of individual molecules remain hidden. The energy transfer within photosynthetic complexes is however sensitive to changes in the spectroscopic properties of the participating subunits. Knowledge about heterogeneities is therefore important for the description of the energy transfer in photosynthetic systems. Here, the recording of the fluorescence emission of single PEC molecules is used as a tool to obtain such information. Spectrally resolved detection as well as double resonance excitation of single PEC molecules is used to investigate their bleaching behavior. The trans isomer of the phycoviolobilin chromophore is identified as a short-lived dark state of monomeric PEC. Polarization sensitive single molecule detection is used for the direct observation of the energy transfer in individual PEC molecules. The experiments reveal that more than one-half of the PEC molecules exhibit an energy transfer behavior significantly different from the bulk. These heterogeneities persist on a time scale of several seconds. Model calculations lead to the conclusion that they are caused by minor shifts in the spectra of the chromophores.