Polymers and surfactants on the basis of renewable resources

A new strategy for the preparation of different polymers and special surfactants was developed. First, unsaturated fatty acid methyl esters obtained from plant oils were converted to terminally unsaturated esters and alpha-olefins by metathesis with ethylene using heterogeneous rhenium or homogeneous ruthenium catalysts. These esters were directly copolymerized with ethylene by an insertion-type palladium-catalyzed polymerization to functionalized polyolefins. Polyesters were synthesized by metathetical dimerization of omega-unsaturated esters and subsequent polycondensation of the produced internally unsaturated dicarboxylic esters or by acidic transesterification with petrochemical diols and additional acyclic diene metathesis polymerization. Omega-epoxy fatty acid methyl esters, achieved by a new method of chemo-enzymatic epoxidation, were converted into polyethers with comb-structure catalyzed by aluminoxanes on the one hand and into sugar surfactants by nucleophilic ring-opening with amino carbohydrates on the other hand.     

Identifikation geeigneter Nachweismöglichkeiten von hormonaktiven und reproduktionstoxischen Wirkungen in aquatischen Ökosystemen

Background and objectives There is an urgent need to detect, assess, and reduce effects of hormonally active compounds and endocrine disrupters in aquatic systems, as reflected in national research programs like the Swiss NRP 50 “Endocrine Disruptors” and its consensus platforms. As a medium-term measure, the EU strategy on endocrine disruptors (SEC(2007)1635) uses the Endocrine Disruptor Testing and Assessment (EDTA) Task Force of the Organisation for Economic Co-operation and Development (OECD) along with other research activities. In particular the test methods of the OECD that are currently in validation or already validated may contribute to a better understanding of the extent of endocrine disruption, in particular if they are applied on environmental samples and in the context of risk-assessment strategies, for instance in waste water treatment. This article aims to give an overview and an evaluation on available and validated biological test systems for the detection of endocrine disruptive and reproductive effects in aquatic systems. Based on this a recommendation for a modular ecotoxicological test platform is given. The study focuses on test methods for sex hormone active substances. Material and methods On the basis of an extensive literature search and ongoing international validation efforts by the OECD for methods to detect endocrine disruptive effects, 15 biological test methods (5 in vivo and 10 in vitro) were selected. Comprising, for example, of eight OECD methods and three out of five in-vitro methods mentioned in the Global Water Research Coalition (GWRC) report “Tools to detect estrogenic activity in environmental waters” (Leusch 2008). Experienced users and developers were then asked to rate the test according to given relevant criteria. The resulting criteria profiles were compiled, compared, and evaluated. Results The methods were selected on the basis of validation status, distribution, their suitability for standardisation, and their proven sensitivity for environmental samples. We assumed that specific YES/YAS-procedures and the ER/AR Calux systems achieve the mentioned criteria. In the case that strong cytotoxicity of environmental samples affects the applicability of cellular reporter gene assays, alternatively a molecular receptor binding assay (e.?g. ELRA) could be used. Additional molecular receptor binding assays are currently in validation by the OECD. Modulating effects on steroidgenesis and probably even on aromatase activity can be detected by the OECD validated H295R Steroidgenesis Assay. Its applicability for environmental samples is currently tested. As in-vivo methods different fish assays (e.?g. Fish Screening Assay and the Zebrafish Embryo Test) were evaluated. For the detection of effects on the thyroid-associated hormone system the Amphibian Metamorphosis Assay (XEMA, for Xenopus Metamorphosis Assay) will soon be available as an OECD-Guideline. Because of trends in the international community to avoid tests with vertebrates in the future, only an optional recommendation was given for such tests. Reproduction toxicity, on the other hand, can be sensitively tested by the tests using the gastropod Potamopyrgus antipodarum, which, as invertebrate tests, do not require a permit to perform animal testing procedures. This test is also sensitive for many substances which are able to induce an endocrine disruption in vertebrates. Its validation is currently performed by the OECD. The applicability of the herein proposed test methods of the modular test platform for environmental-sample assessments were previously confirmed by several published scientific studies. Discussion We propose several test methods to be included in an application-oriented modular test platform. These tests should be suitable to efficiently indicate different mechanisms of endocrine disruption and reproduction toxicity, and may be employed in different situations according to their respective advantages. The modular test platform is able to detect impacts on the reproduction relevant effects in invertebrates, amphibians, and fishes. Furthermore the different mode of actions of estrogenic and androgenic receptor binding, steroid genesis and perhaps even the modulation of aromatase are detectable. A research report on the relevance of endocrine substances and pharmaceuticals in aquatic environments (Moltmann et al. 2007) showed that endocrine end-points of in-vivo tests (31 of 71 tested substances) tend to be more sensitive than general ecotoxicological end-points, such as mortality and growth. Consequently, endocrine and general-toxic effects should be detected in an integrative manner by ecotoxicological test platforms. Conclusions By combining literature research with a targeted query for information about the chosen test procedures it was possible to obtain a detailed overview about the current state-of-the-art of science and technology in the detection of hormone-active effects and reproduction toxicity. Ecotoxicological and regulative aspects were considered equally, and the applicability of the test procedures was evaluated. Because of the diversity of endocrine disrupting mechanisms, a modular combination of in-vivo and in-vitro methods in a joint test platform is needed to recognise and differentiate the transitions from hormone-active effects to endocrine disruption. Recommendations and perspectives Our study leads to a proposal of a modular ecotoxicological test platform, which offers an integrative detection of hormone-active and reproduction-relevant effects in the aquatic environment. The modular system presented here allows the switching between test modules according to the continuously developing state-of-the-art of science and technology as well as the incorporation of novel developments. Further standardisation of such methods for regulative applications is recommended.     

The economics of harem maintenance in the sac-winged bat, Saccopteryx bilineata (Emballonuridae)

Saccopteryx bilineata has a polygynous mating system in which males defend females in a harem territory. Harem defense and courtship include energetically costly flight maneuvers and hovering displays. We tested if (1) harem males have a greater field metabolic rate than non-harem males or females and if (2) the field metabolic rate of harem males is correlated with the number of females in a harem territory. We measured the energy budget in 32 S. bilineata with the doubly labeled water method and compared these estimates with behavioral observations in the daytime roost. Among adult bats, field metabolic rate varied with body mass by an exponent of approximately two. We found no significant difference in field metabolic rate or mass-specific field metabolic rate between harem and non-harem males. The mass-specific field metabolic rate of harem-males increased with harem size. The latter finding supports the hypothesis that the energy costs of courtship display and territorial defense influence the energy budget of harem males. Overall, field metabolic rates of S. bilineata were lower than those of similarly sized bats of the temperate zone and only 2.3 times above the basal metabolic rate recorded for this species. We suggest that male S. bilineata did not take advantage of their metabolic capacity because a prudent allocation of energy to activities of harem maintenance is an adaptive strategy for males in this mating system.     

(−)-Acetylcarnitin und Succinatoxydation

The Science of Nature -     

Metabolic enzymes in coelomic cells (eleocytes) of the polychaete Nereis virens: sex specific changes during sexual maturation

The activities of some enzymes of the intermediary metabolism and the content of soluble protein and carbohydrate (glycogen plus free glucose) were measured in one type of coelomic cells (eleocytes) of the polychaete Nereis virens. Specimens used in this study were collected between 1989 and 1991 in Oosterscheldt Bay, The Netherlands, and divided into six different stages of sexual maturation as determined by the mean oocyte volume. In both sexes, the soluble protein content in eleocytes of immature individuals (11 mg ml^–1 cell vol) increased three-fold. In prespawning N. virens the soluble protein content decreased to less than 2 mg protein ml^–1 cell vol in females but not in males. In both sexes, the carbohydrate content decreased continuously from immature [300 mol glucose equivalent (equiv) ml^–1 cell vol] to prespawning individuals (< 40 mol glucose equiv ml^–1 cell vol). During the time course of maturation, the specific activities (expressed as units mg^–1 protein) of pyruvate kinase, phosphoenolpyruvate carboxykinase, malate dehydrogenase, alanine aminotransferase and glutamate dehydrogenase decreased in both sexes. A transient increase in the specific activities was found for glycogen phosphorylase and aspartate aminotransferase. No major changes were found for hexokinase, lactase dehydrogenase, glucose-6-phosphate dehydrogenase and malic enzyme. Sex specific differences were found for the activities of citrate synthase and isocitrate dehydrogenase, which were higher in males. the specific activities of the latter enzyme increased more than ten-fold in males, but only four-fold in female eleocytes during maturation. In eleocytes of prespawning females, the activities of most enzymes showed extremely high variations not found in prespawning males. For two enzymes of fatty acid catabolism, -hydroxyacyl-CoA dehydrogenase and -hydroxybutyrate dehydrogenase, only traces of activities were detected, suggesting the absence of significant fatty acid catabolism in the eleocytes. Compared to the eleocytes, the body wall tissue showed ten-fold higher activities of phosphofructokinase, whereas the eleocytes displayed higher activities of the amino acid interconverting enzymes glutamate dehydrogenase and alanine aminotransferase and the glyconeogenic enzyme phosphoenolpyruvate carboxykinase. Citrate synthase activities were similar for both tissues. In the coelomic fluid of N. virens, glucose (< 0.1 to 3.5 mM) and d-lactate (0.1 to 4 mM) were present and represent exogenous substrates for the eleocyte metabolism.     

Performance of two swine manure treatment systems on chemical composition and on the reduction of pathogens

Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid–liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen – TKN – and NH₃), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required.