Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp)

Goal, Scope and Background In contrast to inventory data of energy and transport processes, public inventory data of chemicals are rather scarce. Chemicals are important to consider in LCA, because they are used in the production of many, if not all, products. Moreover, they may cause considerable environmental impacts. For these reasons, it was one goal of the new ecoinvent database to provide LCI data on chemicals. In this paper, the methods and procedures used for establishing LCIs of chemicals in ecoinvent are presented.Methods Three different approaches are suggested for situations of differing data availability. First, in the case of good data availability, the general quality guidelines of ecoinvent can be followed. Second, a procedure is proposed for the translation of aggregated inventory data (cumulative LCI results) from industry into the ecoinvent format. This approach was used, if adequate unit process data was not available. Third, a procedure is put forward for estimating inventory data using stoichiometric equations from technical literature as a main information source. This latter method was used if no other information was available. The application of each of the three procedures is illustrated with the help of a case study.Results and Conclusion When sufficient information is available to follow the general guidelines of ecoinvent, the resulting dataset is characterized by a high degree of detail, and it is thus of high quality. For chemicals, however, the application of the standard procedure is possible in only a few cases. When using industrial data, the main drawback is the fact that those data are often available only as aggregated data, thus being out of tune with the quality guidelines of ecoinvent and its main aim, the harmonization of LCI data. As a third approach, the use of the stoichiometric reaction equation is used for the compilation of LCI datasets of chemicals. This approach represents an alternative to neglecting chemicals completely, but it contains a high risk to not consider important aspects of the life cycle of the respective substance.Outlook Further work in the area of chemicals should focus on an improvement of datasets, so far established by either of the two estimation procedures (APME method; estimation based on technical literature) described. Besides the improvement of already established inventories, the compilation of further harmonized inventories of specific types of chemicals (e.g. solvents) or of chemicals for new industrial sectors (e.g. electronics industry) are in discussion.     

Survey of Motile Microaerophilic Bacterial Morphotypes in the Oxygen Gradient above a Marine Sulfidic Sediment

Enrichment cultures for free-swimming microaerophilic bacteria were prepared from marine sulfidic sediment samples (Nivå Bay, Denmark). We observed nine different morphotypes; three of these morphotypes represented already-described species, i.e., Thiovulum majus, “Candidatus Ovobacter propellens,” and an as-yet-unnamed large vibrioid bacterium. In addition, we observed several morphotypes of spirilla and one vibrioid morphotype. A common feature of all investigated bacteria was that they aggregated chemotactically at the oxic-anoxic interface, whereas preferred oxygen concentration were in the range of 1 to 10 μM. The motile behavior and flagellar dynamics are analyzed in detail with an emphasis on spirilla.     

Functional Analysis of Three Plasmids from Lactobacillus plantarum

Lactobacillus plantarum WCFS1 harbors three plasmids, pWCFS101, pWCFS102, and pWCFS103, with sizes of 1,917, 2,365, and 36,069 bp, respectively. The two smaller plasmids are of unknown function and contain replication genes that are likely to function via the rolling-circle replication mechanism. The host range of the pWCFS101 replicon includes Lactobacillus species and Lactococcus lactis, while that of the pWCFS102 replicon also includes Carnobacterium maltaromaticum and Bacillus subtilis. The larger plasmid is predicted to replicate via the theta-type mechanism. The host range of its replicon seems restricted to L. plantarum. Cloning vectors were constructed based on the replicons of all three plasmids. Plasmid pWCFS103 was demonstrated to be a conjugative plasmid, as it could be transferred to L. plantarum NC8. It confers arsenate and arsenite resistance, which can be used as selective markers.     

Occurrence and Relatedness of Vancomycin-Resistant Enterococci in Animals, Humans, and the Environment in Different European Regions

Vancomycin-resistant enterococcci (VRE) in Europe are thought to have emerged partly due to the use of the glycopeptide avoparcin in animal husbandry. We compared the occurrence of VRE in geographical regions of Europe in which until 1997 large amounts of avoparcin were used (Spain, United Kingdom, and Denmark) with the occurrence of VRE in Sweden, where avoparcin was banned in 1986. We also studied the relatedness between VRE strains from different regions and habitats. In total, 2,580 samples were collected from humans, animals, and the environment (soil, sewage, recipient water). VRE resistant to 20 μg/ml vancomycin were identified in 8.2% of the samples and were found most frequently in raw and treated urban sewage samples (means, 71% and 36% of the samples, respectively), pig manure (17%), and hospital sewage (16%). The proportions of VRE-positive sewage samples were similar in Sweden, Spain, and the United Kingdom, whereas pig feces and manure were more often positive in Spain than in Sweden (30% versus 1%). Most VRE were Enterococcus faecium carrying vanA, and computerized biochemical phenotyping of the isolates of different ecological origins showed a high degree of polyclonality. In conclusion, it seems that animal-associated VRE probably reflect the former use of avoparcin in animal production, whereas VRE in human-associated samples may be a result of antibiotic use in hospitals. Since there seems to be a reservoir of the resistance genes in all countries studied, precautions must be taken to limit the use of antibiotics and antibiotic-like feed additives.     

Galanin immunoreactivity increased in chicken supraoptic neurons after activation of the vasotocin system at oviposition

The avian arginine vasotocin (AVT) synthesized in the hypothalamic magnocellular neurons and released from the posterior pituitary is known to be involved in the regulation of uterine contractions for oviposition in chickens. However, regulation of AVT synthesis and release within the magnocellular hypothalamus has not been elucidated. Galanin, the oviposition inducing factor in the oviduct of the hen, has been demonstrated to have sexually dimorphic stimulatory action in oxytocin- and vasopressin neurons in the mammalian hypothalamus. In this study, galanin and AVT immunoreactivity was investigated around the time of oviposition in the supraoptic nucleus (SON) to determine if galanin modulates AVT synthesis and/or release. Within SON neurons increased AVT immunoreactivity before oviposition and the decreased AVT immunoreactivity after oviposition implied function-related peptide release. The significantly increased number of galanin neurons co-localizing with AVT immediately after oviposition suggests that galanin is involved in the negative feedback to limit AVT release in the SON. Thus, these data support the idea that AVT in the SON is involved in central regulation of oviposition and that AVT release could be modulated by the neuropeptide galanin.     

Homologous recombination in real time: DNA strand exchange by RecA

Homologous recombination, the exchange of strands between different DNA molecules, is essential for proper maintenance and accurate duplication of the genome. Using magnetic tweezers, we monitor RecA-driven homologous recombination of individual DNA molecules in real time. We resolve several key aspects of DNA structure during and after strand exchange. Changes in DNA length and twist yield helical parameters for the protein-bound three-stranded structure in conditions in which ATP was not hydrolyzed. When strand exchange was completed under ATP hydrolysis conditions that allow protein dissociation, a "D wrap" structure formed. During homologous recombination, strand invasion at one end and RecA dissociation at the other end occurred at the same rate, and our single-molecule analysis indicated that a region of only about 80 bp is actively involved in the synapsis at any time during the entire reaction involving a long ( approximately 1 kb) region of homology.     

Species richness of herbivores on exotic host plants increases with time since introduction of the host

Aim Species richness of insect herbivores feeding on exotic plants increases with abundance as well as range size of the host in the area of introduction. The formation of these herbivore assemblages requires a certain amount of time, and the richness of insect faunas should also increase with the length of time an exotic plant has been present in the introduced range. Location Central Europe. Methods We analysed the variation in species richness of leaf‐chewing Lepidoptera larvae and sap‐sucking Auchenorrhyncha (Hemiptera) associated with 103 exotic woody plant species in Germany in relation to time since introduction, range size, growth form (trees versus shrubs), biogeographical origin (distance from Central Europe) and taxonomic isolation of the host plant (presence or absence of a native congener in the introduced area). Results Using simple correlation analyses we found for Lepidoptera and Auchenorrhyncha that species richness increased with time since introduction of the host plant. For the Lepidoptera the increase of species richness with time since introduction remained significant even after removing the effects of all other independent variables. Main conclusions Our results provide some evidence that assemblages of insects on exotic plants do not reach saturation within a time scale of few hundred years. This contrasts with previous findings for crop plants.     

Production of epoxide hydrolases in batch fermentations of <Emphasis Type="Italic">Botryosphaeria rhodina</Emphasis>

The filamentous fungus Botryosphaeria rhodina (ATCC 9055) was investigated related to its ability for epoxide hydrolase (EH) production. Epoxide hydrolase activity is located at two different sites of the cells. The larger part is present in the cytosol (70%), while the smaller part is associated to membranes (30%). In media optimization experiments, an activity of 3.5 U/gDW for aromatic epoxide hydrolysis of para-nitro-styrene oxide (pNSO) could be obtained. Activity increased by 30% when pNSO was added to the culture during exponential growth. An increase of enzyme activity up to 6 U/gDW was achieved during batch-fermentations in a bioreactor with 2.7 l working volume. Evaluation of fermentations with 30 l working volume revealed a relation of oxygen uptake rate to EH expression. Oxygen limitation resulted in a decreased EH activity. Parameter estimation by the linearization method of Hanes yielded Km values of 2.54 and 1.00 mM for the substrates S-pNSO and R-pNSO, respectively. vmax was 3.4 times higher when using R-pNSO. A protein purification strategy leading to a 47-fold increase in specific activity (940 U/mgProtein) was developed as a first step to investigate molecular and structural characteristics of the EH.     

Expressed sequence tag-derived microsatellite markers of perennial ryegrass (Lolium perenne L.)

An expressed sequence tag (EST) library of the key grassland species perennial ryegrass (Lolium perenne L.) has been exploited as a resource for microsatellite marker development. Out of 955 simple sequence repeat (SSR) containing ESTs, 744 were used for primer design. Primer amplification was tested in eight genotypes of L. perenne and L. multiflorum representing (grand-) parents of four mapping populations and resulted in 464 successfully amplified EST-SSRs. Three hundred and six primer pairs successfully amplified products in the mapping population VrnA derived from two of the eight genotypes included in the original screening and revealed SSR polymorphisms for 143 ESTs. Here, we report on 464 EST-derived SSR primer sequences of perennial ryegrass established in laboratory assays, providing a dedicated tool for marker assisted breeding and comparative mapping within and among forage and turf grasses. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.