Insekten als Nahrungsmittel der Zukunft

Insects as a sustainable food of the future In Germany insects are still relatively unknown as foodstuff. However, in many countries of the world insects have been valued as foodstuff for a long time. This article examines the sustainability potential of entomophagy. Based on legal and psychological barriers it tries to explain why insects are not on the menu in Germany. Research in the fields of nutritional psychology and biodidactics is essential for the successful introduction of insects as foodstuff in Germany.     

Vegetarismus. Mehr als ein Ernährungsstil

Vegetarianism During recent decades the social standing of vegetarians has improved considerably. Scientific studies show convincingly that a well balanced lacto‐ovo‐vegetarian diet can provide an optimal supply of all nutrients for everybody. Vegetarians practice their nutrition predominantly for ethical reasons, health concerns and ecological considerations. Vegetarianism contributes to global nutrition security and to a sustainable management of natural resources. The switch to a vegetarian diet requires conviction and knowledge about the proper selection and preparation of the diet. Vegetarians report about their high quality of life – not only because they live longer.     

Die Wasserlinse – eine unterschätzte Vielzweckpflanze

Tiny, inconspicuous duckweeds (Lemnaceae) are often considered a nuisance, due to their propensity to rapidly cover surfaces of water bodies. However, their pronounced growth potential, together with their particular morphological, clonal and genomic properties and their easy cultivation make them valuable model plants for studies, and have established them as indicator plants in the field of ecotoxicology. Duckweeds can make a valuable contribution to wastewater remediation, and the biomass that their growth thereby provides can be of value in many ways, including energy generation, fuel production and use as fertilizer and animal food. Duckweeds grown under controlled conditions can contribute to human nutrition and serve as biofactories for heterologous protein expression. The versatile usage potential of duckweeds has not been thoroughly exploited, as it could and should be in the future.     

Gesundheit und Ernährung: Die Macht der Kultur

Health and nutrition: The power of cultural patterns Despite enormous educational efforts and widely spread common knowledge about the subject, today's nutrition as it is practiced by many consumer groups concerning health in Germany, shows great potential to be optimized. On one side this is due to a cognitive dissonance: The knowledge about a healthy nutrition is opposed to a practice that is often detrimental to health. Among other factors, the main reasons for that phenomenon can be found within psychological aspects of nutrition: Practices that are tried and tested have a stabilizing effect and lead to emotional security. On the other side nutritional systems in principle change slowly and are difficult to control, especially since food itself and communicating about it function as ideological placings, as a representation of status or are matter of distinction in a society driven by modern lifestyles. Oftentimes supposedly reasonable nutritional practices hardly show any commonalities with these realities. Furthermore people who live in Germany but who were socialized with a different cultural background tend to have conceptions of a valuable nutrition that are often contradictorily to scientific findings. That also counts for people who obtain information from internet platforms that are not scientifically oriented. There they pick up superficial knowledge, esoteric beliefs or ideology‐based hints delivered through a science‐based appearance.     

Das Wattenmeer als gemeinsame Verantwortung verstehen

Understanding the Wadden Sea as a shared responsibility The Wadden Sea is the largest tidal flat system in the world, where natural processes run undisturbed. The World Heritage site is home to over 10,000 species of plants and animals, which continuously adapt to the ever‐changing dynamic area. 10–12 million migratory birds yearly rely on the Wadden Sea as a stopover. To ensure its protection, the three countries have been joining efforts for the sea's conservation since 1978, taking responsibility for this irreplaceable ecosystem and preserving it for the benefit of present and future generations. One of the cooperation's main pillars is the harmonised, cross‐border Trilateral Monitoring and Assessment Programme.     

Circadiane Uhren und Energiemetabolismus

Chrononutrition – circadian clocks and energy metabolism Genetically encoded endogenous clocks regulate 24‐hour rhythms of physiology and behavior. A central pacemaker residing in the suprachiasmatic nucleus synchronizes peripheral clocks found in all tissues with each other and with the external day‐night cycle. One function of circadian clocks is the regulation of energy metabolism via rhythmic activation of tissue‐specific clock‐controlled genes. In the liver, genes involved in glucose and lipid metabolism are regulated in this fashion, while in adipocytes, fatty acid release and adipokine secretion are controlled by the circadian clock. Disruption of circadian rhythms as seen, for example, in shift workers promotes the development of metabolic disorders such as obesity and type‐2 diabetes.     

Acetylcholin als non‐neuronales Signalmolekül

The non‐neuronal cholinergic system Lately there was increasing evidence that acetylcholine plays an important role as a signalling molecule in non‐neuronal cells, besides its well known function as a neurotransmitter. The so‐called non‐neuronal cholinergic system (NNCS) was detected in many organs such as lung, skin and placenta, where it is involved in the regulation of diverse physiological processes. Additionally there is increasing evidence that the NNCS may be involved in the pathogenesis of diseases such as cystic fibrosis. Therefore detailed investigation of the NNCS is essential for a better understanding of human physiology and for developing improved therapies.     

Biodiversitätsforschung – wohin geht die Reise?

Biodiversity and biodiversity politics Extrapolations for a range of indicators suggest that based on current trends, pressures on biodiversity will continue to increase (Global Biodiversity Outlook 4, 2014). Since services of nature, like fertile soil, clear water and clean air are achieved by consortia of organisms rather than by individual species, they are already endangered. This holds, in spite of the fact, that only 10% of the earth's organisms are known to science and that therefore the loss caused by global change cannot be reliably quantified. Today, science develops new methods for recording consortia of coexisting organisms in a habitat. With the Convention on Biological Diversity, biodiversity has become a matter of politics which is welcome with respect to species and habitat conservation, but the concern of biopiracy creates bureaucratic hurdles hindering research. The most recent achievement is IPBES (Intergovernmental Platform on Biodiversity and Ecosystem Services, Bonn), which strives to bring more science into biodiversity politics.     

Personalisierte Medizin – Vision oder Fiktion? Beispiel: Altersdiabetes

Typical civilization diseases, such as type II diabetes, are common, complex in the underlying pathogenic mechanisms, heterogenous in the phenotype and multifactorial due to a wide variety of possible combinations of disease susceptibility or protective genes in different relevant tissues and negative or positive environmental factors. This is in sharp contrast to classical inherited diseases, such as Chorea Huntington, which are often caused by complete loss‐ or gain‐of‐function mutations in a single gene. The causative polymorphisms of susceptibility genes, however, are characterized by relative subtle alterations in the function of the corresponding gene product, which per se do not support the pathogenesis, by high frequency, high expenditure for their identification and rather low predictive value. Consequently, the reliable and early diagnosis of civilization diseases depends on the individual determination of all (or as many as possible) polymorphisms of each susceptibility gene together with the corresponding gene products and the metabolites emerging thereof.     

Das Geheimnis des roten Herbstlaubes

The secret of the fall colour red The autumnal coloration of trees and shrubs in temperate climate regions is a well‐known spectacle of nature. Crucial for the yellow colour of leaves is the degradation of chlorophylls which cover the yellow colour of carotenoids. Chlorophyll degradation is a prerequisite for protein degradation and remobilization of precious nitrogen in the amino acids of the chloroplast proteins. In some species leaves turn red in autumn by accumulation of anthocyanins. Anthocyanins can reduce photo‐oxidative stress by acting as a sunscreen shielding against the harmful effects of excess light. Furthermore, anthocyanins prevent the landing of insects – in particular aphides.     

Experimente mit Hefe (2)

The so‐called iodine test is ideal for demonstrating the role of the enzyme “amylase” in simple experiments based on a colour reaction when a yeast dough rises, when carbohydrates are digested or when dishes are washed in the dishwasher. The experiments presented can be used to clarify the question of which everyday substances are capable of degrading starch or whether a food contains starch or not. The central question of the experiments is, how yeast makes the bread dough rise despite of its “starch intolerance”.     

Zuckerbrot und Peitsche

Marantaceae (arrowrood) are among the few examples of plants showing unexpectedly fast movements such as the ones in the meaningful mimosa or carnivorous plants. In the Venus flytrap (Dionaea), the movement of leaves is an extreme fast reaction to mechanical stimuli and based on the propagation of electrical signals. Of course, it was interesting to investigate, whether the explosively moving style of Marantaceae is based on a comparable mechanism. Electrophysiological experiments helped to understand how one of the fastest movements in the plant kingdom is mediated.     

Wie wachsen Tropenbäume? Jahrringe als Ausdruck von Klimabedingungen und Lebensform

Growth of tropical trees is largely depending on the seasonality of the local climate. In many trees growing in areas with a distinct dry season, cambial activity ceases resulting in the formation of annual rings. In very humid mountain rainforests, trees stop to grow already after short rainless periods. By a combination of increment measurements and wood anatomical analyses, the climatic control of wood formation can be assessed. Intra‐annual wood density variations and content of various stable isotopes enable the climatological interpretation of the “wood signals”.     

Biodiversität und Klima: Wandel in vollem Gange!

Global change is in full progress! Global change is in full progress and includes world‐wide climatic and biodiversity changes. Alterations of land and water use in many areas as well as passive and active spreading of exotic species are further drivers of change. Mankind is impacted in many respects. Global change will lead in many countries to increasing poverty and will result in political instability. The research about causes and consequences of biological and climatic changes and the discussion within the society is therefore a crucial challenge.     

Radioaktivität – Wirkung auf die Zelle

Radioactive radiaton As long as the earth exists all living organisms are exposed to a natural radioactive radiation. Man succeeded by knowledge of the structure of matter, to use the natural process of radioactive decay for peaceful (medicine, energy) and military means (nuclear bombs). Hence, the artificial radiation created by humans and the amount of radioactive “waste” has considerably increased in the last 100 years. After the incidents of Chernobyl (Russia), and Fukushima (Japan) the use of nuclear energy appears to be not as controllable as expected. An unsolved problem is still the “disposal” and storage of radioactive materials. With the production and use of radioactive substances in large quantities, we leave a currently unsolved problem to future generations for thousands of years.     

Das Oligozän. Subtropisches Leben in einem langen,schmalen Meer

The Oligocene Even as a general cooling can be proved during the Oligocene, there is still a subtropical climate in Central Europe, due to the following plate tectonic movements. This is the last time in which there are clues for a direct seaway connecting the North‐ and Mediterranean Seas. This basin along the Upper Rhine Valley as well as the additional north alpine Molasse Basin are the results of folding and lifting of the Alps. Life in these seas and lowlands corresponds more or less to the current subtropical ecosystems.     

Mikrobiologie in der Schule

In the project “The hidden world of bacteria” students from six classes from high schools around Salzburg work for two years together with staff members of the Research Department for Limnology, Mondsee (University of Innsbruck). The aim is to isolate new bacterial strains from surrounding inland waters and to describe them as new species or higher taxonomic units.     

Production of bioethanol from four species of duckweeds (Landoltia punctata,Lemna aequinoctialis,Spirodela polyrrhiza,and Wolffia arrhiza) through optimization of saccharification process and fermentation with Saccharomyces cerevisiae

Duckweeds are promising potential sources for bioethanol production due to their high starch content and fast growth rate. We assessed the potential for four species, Landoltia punctata, Lemna aequinoctialis, Spirodela polyrrhiza, and Wolffia arrhiza, for bioethanol production. We also optimized a possible production procedure, which must include saccharification to convert starch to soluble sugars that can serve as a substrate for fermentation. Duckweeds were cultivated on 10% Hoagland solution for 12 days, harvested, dried, homogenized, and dissolved in solutions that were tested as substrates for bioethanol production by the yeast Saccharomyces cerevisiae. First, we optimized the saccharification process, including the ideal ratio of the enzyme used to convert starch into simple sugars. The greatest starch-to-sugar conversion was obtained when the α-amylase and amyloglucosidase was 2:1 (v/v) and with a 24 h incubation period at 50 °C. After saccharification, the solutions were incubated with the yeast, S. cerevisiae. The fermentation process was carried out for 48 h with 10% (v/v) yeast inoculum. The ethanol content was maximal approximately 24 h after the start of incubation, and the sugars and protein were minimal, with little change over the next 24 h. The final ethanol concentration obtained were 0.19, 0.17, 0.19, and 0.16 g ethanol/g dry biomass for L. punctata, L. aequinoctialis, S. polyrrhiza, and W. arrhiza respectively. We suggest that these four species of duckweed have the potential to serve sources of bioethanol and hope that the procedure we have optimized proves useful in the endeavour.     

Bioenergie aus Knöterich und Kuhmist

Bioenergy from Fallopia japonica and cow dung This article investigates whether Fallopia japonica, a rampant neophyte in Germany, is a suitable alternative to maize as an energy crop. To this end, parts of the plant which had been harvested overground were shredded, fermented in a Hohenheim Biogas Yield Test and the amount of methane produced thereby was determined. The results indicate that Fallopia japonica yields values which are comparable to the results obtained for maize and thus represents a possible alternative as an energy crop. Thus a weed could be controlled and put to an ecologically and economically efficient use. This study was carried out within student the competition by the Siemens Foundation and awarded a prize.     

Direct production of ethanol from neoagarobiose using recombinant yeast that secretes α-neoagarooligosaccharide hydrolase

An α-neoagarooligosaccharide hydrolase, AgaNash, was purified from Cellvibrio sp. OA-2007, which utilizes agarose as a substrate. The agaNash gene, which encodes AgaNash, was obtained by comparing the N-terminal amino acid sequence of AgaNash with that deduced from the nucleotide sequence of the full-length OA-2007 genome. The agaNash gene combined with the Saccharomyces cerevisiae signal peptide α-mating factor was transformed into the YPH499 strain of S. cerevisiae to generate YPH499/pTEF-MF-agaNash, and the recombinant yeast was confirmed to produce AgaNash, though it was mainly retained within the recombinant cell. To enhance AgaNash secretion from the cell, the signal peptide was replaced with a combination of the signal peptide and a threonine- and serine-rich tract (T-S region) of the S. diastaticus STA1 gene. The new recombinant yeast, YPH499/pTEF-STA1SP-agaNash, was demonstrated to secrete AgaNash and hydrolyze neoagarobiose with an efficiency of as high as 84%, thereby producing galactose, which is a fermentable sugar for the yeast, and ethanol, at concentrations of up to 1.8 g/L, directly from neoagarobiose.