Showing papers by "University of Hohenheim published in 2007"

Role of mast cells in allergic and non-allergic immune responses: comparison of human and murine data

Abstract: The versatile role of mast cells in allergy, in innate immune responses and in the regulation of tissue homeostasis is well recognized. However, it is often not made clear that most mast-cell data derive solely from experiments in mice or rats, species that obviously never suffer from allergic and most other mast-cell-associated human diseases. Data on human mast cells are limited, and the mast-cell source and species from which findings derive are frequently not indicated in the titles and summaries of research publications. This Review summarizes recent data on human mast cells, discusses differences with murine mast cells, and describes new tools to study this increasingly meaningful cell type in humans.

Phorbol esters: structure, biological activity, and toxicity in animals.

Abstract: Phorbol esters are the tetracyclic diterpenoids generally known for their tumor promoting activity. The phorbol esters mimic the action of diacyl glycerol (DAG), activator of protein kinase C, which regulates different signal transduction pathways and other cellular metabolic activities. They occur naturally in many plants of the family Euphorbiacaeae and Thymelaeaceae. The biological activities of the phorbol esters are highly structure specific. The phorbol esters, even at very low concentrations, show toxicological manifestations in animals fed diets containing them. This toxicity limits the use of many nutritive plants and agricultural by-products containing phorbol esters to be used as animal feed. Therefore, various chemical and physical treatments have been evaluated to extract or inactivate phorbol esters so that seed meals rich in proteins could be used as feed resources. However, not much progress has been reported so far. The detoxifying ability has also been reported in some molluscs and in liver homogenate of mice. Besides, possessing antinutritional and toxic effects, few derivatives of the phorbol esters are also known for their antimicrobial and antitumor activities. The molluscicidal and insecticidal properties of phorbol esters indicate its potential to be used as an effective biopesticide and insecticide.

Plant Secondary Metabolites

Abstract: Plant secondary metabolites , Plant secondary metabolites , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Computing Heritability and Selection Response From Unbalanced Plant Breeding Trials

Abstract: Heritability is often used by plant breeders and geneticists as a measure of precision of a trial or a series of trials. Its main use is for computing the response to selection. Most formulas proposed for calculating heritability implicitly assume balanced data and independent genotypic effects. Both of these assumptions are often violated in plant breeding trials. This article proposes a simulation-based approach to tackle the problem. The key idea is to directly simulate the quantity of interest, e.g., response to selection, rather than trying to approximate it using some ad hoc measure of heritability. The approach is illustrated by three examples.

Bioactivity of phytochemicals in some lesser-known plants and their effects and potential applications in livestock and aquaculture production systems.

Abstract: Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field.

Lipofuscin: formation, distribution, and metabolic consequences

Abstract: One of the highlights of postmitotic aging is the intracellular accumulation of highly oxidized and cross-linked proteins, known as lipofuscin Lipofuscin is insoluble and not degradable by lysosomal enzymes or the proteasomal system, which is responsible for the recognition and degradation of misfolded and oxidatively damaged proteins These aggregates have been found in various cell types, including heart, liver, kidney, neuronal tissue, and dermal tissue, and are associated with the life span of a single postmitotic cell and, consequently, of the whole organism Lipofuscin formation appears to depend on the rate of oxidative damage to proteins, the functionality of mitochondrial repair systems, the proteasomal system, and the functionality and effectiveness of the lysosomes This review highlights the current knowledge of the formation, distribution, and effects of lipofuscin in mammalian cells

Meta-Analysis of the Relationship Between the Big Five and Academic Success at University

Abstract: . Interest in the prediction of academic success in higher education has grown considerably in recent years in German-speaking countries. While the validity of school grades and admission tests has been investigated by meta-analyses and large-scale studies at least in the United States, less is known about noncognitive predictors of academic success. The present meta-analysis investigates the impact of the Big Five personality factors on academic success at university. A total of 258 correlation coefficients from 58 studies published since 1980 were included. Grades, retention, and satisfaction served as success criteria. Correlations were corrected for attenuation caused by measurement error. Results show that the influence of personality traits on academic achievement depends on the success criterion. While Neuroticism is related to academic satisfaction (? = -.369, k = 8), Conscientiousness correlates with grades (? = .269, k = 41). Extraversion, Openness to Experience, and Agreeableness have n...

Soil organic carbon stocks in China and changes from 1980s to 2000s

Abstract: The estimation of the size and changes of soil organic carbon (SOC) stocks is of great importance for decision makers to adopt proper measures to protect soils and to develop strategies for mitigation of greenhouse gases. In this paper, soil data from the Second State Soil Survey of China (SSSSC) conducted in the early 1980s and data published in the last 5 years were used to estimate the size of SOC stocks over the whole profile and their changes in China in last 20 years. Soils were identified as paddy, upland, forest, grassland or waste-land soils and an improved soil bulk density estimation method was used to estimate missing bulk density data. In the early 1980s, total SOC stocks were estimated at 89.61 Pg (1 Pg=103 Tg=1015 g) in China's 870.94 Mha terrestrial areas covered by 2473 soil series. In the paddy, upland, forest and grassland soils the respective total SOC stocks were 2.91 Pg on 29.87 Mha, 10.07 Pg on 125.89 Mha, 34.23 Pg on 249.32 Mha and 37.71 Pg on 278.51 Mha, respectively. The SOC density of the surface layer ranged from 3.5 Mg ha−1 in Gray Desery grassland soils to 252.6 Mg ha−1 in Mountain Meadow forest soils. The average area-weighted total SOC density in paddy soils (97.6 Mg ha−1) was higher than that in upland soils (80 Mg ha−1). Soils under forest (137.3 Mg ha−1) had a similar average area-weighted total SOC density as those under grassland (135.4 Mg ha−1). The annual estimated SOC accumulation rates in farmland and forest soils in the last 20 years were 23.61 and 11.72 Tg, respectively, leading to increases of 0.472 and 0.234 Pg SOC in farmland and forest areas, respectively. In contrast, SOC under grassland declined by 3.56 Pg due to the grassland degradation over this period. The resulting estimated net SOC loss in China's soils over the last 20 years was 2.86 Pg. The documented SOC accumulation in farmland and forest soils could thus not compensate for the loss of SOC in grassland soils in the last 20 years. There were, however, large regional differences: Soils in China's South and Eastern parts acted mainly as C sinks, increasing their average topsoil SOC by 132 and 145 Tg, respectively. In contrast, in the Northwest, Northeast, Inner Mongolia and Tibet significant losses of 1.38, 0.21, 0.49 and 1.01 Pg of SOC, respectively, were estimated over the last 20 years. These results highlight the importance to take measures to protect grassland and to improve management practices to increase C sequestration in farmland and forest soils.

Antibiotic resistances of starter and probiotic strains of lactic acid bacteria.

Abstract: The antibiotic resistances of 45 lactic acid bacteria strains belonging to the genera Lactobacillus, Streptococcus, Lactococcus, Pediococcus, and Leuconostoc were investigated. The objective was to determine antibiotic resistances and to verify these at the genetic level, as is currently suggested by the European “qualified presumption of safety” safety evaluation system for industrial starter strains. In addition, we sought to pinpoint possible problems in resistance determinations. Primers were used to PCR amplify genes involved in β-lactam antibiotic, chloramphenicol, tetracycline, and erythromycin resistance. The presence of ribosomal protection protein genes and the ermB gene was also determined by using a gene probe. Generally, the incidences of erythromycin, chloramphenicol, tetracycline, or β-lactam resistances in this study were low (

Comparison of empirical methods for building agent-based models in land use science

Abstract: The use of agent-based models (ABMs) for investigating land-use science questions has been increasing dramatically over the last decade. Modelers have moved from ‘proofs of existence’ toy models to case-specific, multi-scaled, multi-actor, and data-intensive models of land-use and land-cover change. An international workshop, titled ‘Multi-Agent Modeling and Collaborative Planning—Method2Method Workshop’, was held in Bonn in 2005 in order to bring together researchers using different data collection approaches to informing agent-based models. Participants identified a typology of five approaches to empirically inform ABMs for land use science: sample surveys, participant observation, field and laboratory experiments, companion modeling, and GIS and remotely sensed data. This paper reviews these five approaches to informing ABMs, provides a corresponding case study describing the model usage of these approaches, the types of data each approach produces, the types of questions those data can answer, and an ...

The Organization of High-Affinity Ammonium Uptake in Arabidopsis Roots Depends on the Spatial Arrangement and Biochemical Properties of AMT1-Type Transporters

Abstract: The AMMONIUM TRANSPORTER ( AMT ) family comprises six isoforms in Arabidopsis thaliana . Here, we describe the complete functional organization of root-expressed AMTs for high-affinity ammonium uptake. High-affinity influx of 15 N-labeled ammonium in two transposon-tagged amt1;2 lines was reduced by 18 to 26% compared with wild-type plants. Enrichment of the AMT1;2 protein in the plasma membrane and localization of AMT1;2 promoter activity in the endodermis and root cortex indicated that AMT1;2 mediates the uptake of ammonium entering the root via the apoplasmic transport route. An amt1;1 amt1;2 amt1;3 amt2;1 quadruple mutant ( qko ) showed severe growth depression under ammonium supply and maintained only 5 to 10% of wild-type high-affinity ammonium uptake capacity. Transcriptional upregulation of AMT1;5 in nitrogen-deficient rhizodermal and root hair cells and the ability of AMT1;5 to transport ammonium in yeast suggested that AMT1;5 accounts for the remaining uptake capacity in qko . Triple and quadruple amt insertion lines revealed in vivo ammonium substrate affinities of 50, 234, 61, and 4.5 μM for AMT1;1, AMT1;2, AMT1;3, and AMT1;5, respectively, but no ammonium influx activity for AMT2;1. These data suggest that two principle means of achieving effective ammonium uptake in Arabidopsis roots are the spatial arrangement of AMT1-type ammonium transporters and the distribution of their transport capacities at different substrate affinities.

Nature and significance of anthropogenic urban soils

Abstract: Anthropogenic and natural urban soils are of increasing significance in a world with accelerating urbanization. Thus, anthropogenic urban soils must be considered as an fundamental ecological asset for land-use planning. Furthermore, they are of interest for fundamental soil sciences, since there properties are rarely investigated and can differ substantially from landscape soils. Numerous studies on their properties exist, in particular with respect to contamination. It is argued that urban soils are ecological assets of cities, a point of view shared with the AKS (working group on urban soils within the German Soil Science Society). In this commentary, an overview of less recognized topics is presented with specific reference to topics such as ‘co-development of anthropogenic urban soils within their cities’ and the principles of ‘stock flow of anthropogenic urban soils forming materials’ are discussed to complete the pedological and ecological view on urban soils. Additionally, the significance of (anthropogenic) urban soils is highlighted to strengthen consideration in urban spatial planning. Historical and recent impacts on soils and parent materials are related with soil properties. Definitions and taxonomic terms for anthropogenic soils are presented. Furthermore, the context with the functionality of such soils is discussed. The principles of mapping and evaluation of anthropogenic urban soils are explained to stress the practicability of management tools for such soils. A semi-quantitative consideration of parent material flows in anthropogenic urban soils indicates the enormous increase of the areas of supply of cities since the pre-industrial period. Since 1950, the inner-urban deposition of solid materials, including dust stopped to increase or increases slowly in the early industrialized regions. In contrast, the deposition and reuse of rubble, inorganic and organic waste as well as dust increases much in the late industrialized regions of the last decades. The significance of anthropogenic urban soils in ecological soil management became obvious by numerous scientific studies. Moreover, it is recognized that management of different areas in urban environments must respect the functionality of their soils. It is therefore of importance that pedology is integrated with related disciplines such as archaeology, history and urban planning. The scientific knowledge, the appropriate methods and tools are now available to promote and support the management of anthropogenic urban soils. It is recommended that research conducted over the past two decades should be introduced into soil management, especially with regard to the evaluation of soil quality. Accordingly, results of collaborative studies by soil scientists and city planners need to be integrated into political frameworks like the European Soil Strategy. It is also recognized that knowledge regarding anthropogenic urban soils in the tropics, the southern hemisphere and far north is lacking, a point which will need to be addressed in the future. This publication is dedicated to the 20th anniversary of the AKS (Arbeitskreis Stadtboden).

Temperature sensitivity of microbial respiration, nitrogen mineralization, and potential soil enzyme activities in organic alpine soils

Abstract: [1] Investigations focusing on the temperature sensitivity of microbial activity and nutrient turnover in soils improve our understanding of potential effects of global warming. This study investigates the temperature sensitivity of C mineralization, N mineralization, and potential enzyme activities involved in the C and N cycle (tyrosine amino-peptidase, leucine amino-peptidase, s-glucosidase, s-xylosidase, N-acetyl-s-glucosaminidase). Four different study sites in the Austrian alpine zone were selected, and soils were sampled in three seasons (summer, autumn, and winter). A simple first-order exponential equation was used to calculate constant Q10 values for the C and N mineralization over the investigated temperature range (0–30°C). The Q10 values of the C mineralization (average 2.0) for all study sites were significantly higher than for the N mineralization (average 1.7). The Q10 values of both activities were significantly negatively related to a soil organic matter quality index calculated by the ratios of respiration to the organic soil carbon and mineralized N to the total soil nitrogen. The chemical soil properties or microbial biomass did not affect the Q10 values of C and N mineralization. Moreover, the Q10 values showed no distinct pattern according to sampling date, indicating that the substrate quality and other factors are more important. Using a flexible model function, the analysis of relative temperature sensitivity (RTS) showed that the temperature sensitivity of activities increased with decreasing temperature. The C and N mineralization and potential amino-peptidase activities (tyrosine and leucine) showed an almost constant temperature dependence over 0–30°C. In contrast, s-glucosidase, s-xylosidase, and N-acetyl-s-glucosaminidase showed a distinctive increase in temperature sensitivity with decreasing temperature. Low temperature at the winter sampling date caused a greater increase in the RTS of all microbial activities than for the autumn and summer sampling dates. Our results indicate (1) a disproportion of the RTS for potential enzyme activities of the C and N cycle and (2) a disproportion of the RTS for easily degradable C compounds (s-glucose, s-xylose) compared with the C mineralization of soil organic matter. Thus temperature may play an important role in regulating the decay of different soil organic matter fractions due to differences in the relative temperature sensitivities of enzyme activities.

Evenness drives consistent diversity effects in intensive grassland systems across 28 European sites

Abstract: 1 Ecological and agronomic research suggests that increased crop diversity in species-poor intensive systems may improve their provision of ecosystem services. Such general predictions can have critical importance for worldwide food production and agricultural practice but are largely untested at higher levels of diversity. 2 We propose new methodology for the design and analysis of experiments to quantify diversity-function relationships. Our methodology can quantify the relative strength of inter-specific interactions that contribute to a functional response, and can disentangle the separate contributions of species richness and relative abundance. 3 Applying our methodology to data from a common experiment at 28 European sites, we show that the above-ground biomass of four-species mixtures (two legumes and two grasses) in intensive grassland systems was consistently greater than that expected from monoculture performance, even at high productivity levels. The magnitude of this effect generally resulted in transgressive overyielding. 4 A combined analysis of first-year results across sites showed that the additional performance of mixtures was driven by the number and strength of pairwise inter-specific interactions and the evenness of the community. In general, all pairwise interactions contributed equally to the additional performance of mixtures; the grass-grass and legume-legume interactions were as strong as those between grasses and legumes. 5 The combined analysis across geographical and temporal scales in our study provides a generality of interpretation of our results that would not have been possible from individual site analyses or experimentation at a single site. 6 Our four-species agricultural grassland communities have proved a simple yet relevant model system for experimentation and development of methodology in diversity-function research. Our study establishes that principles derived from biodiversity research in extensive, semi-natural grassland systems are applicable in intensively managed grasslands with agricultural plant species.

Allelopathy in crop/weed interactions--an update.

Abstract: Since varietal differences in allelopathy of crops against weeds were discovered in the 1970s, much research has documented the potential that allelopathic crops offer for integrated weed management with substantially reduced herbicide rates. Research groups worldwide have identified several crop species possessing potent allelopathic interference mediated by root exudation of allelochemicals. Rice, wheat, barley and sorghum have attracted most attention. Past research focused on germplasm screening for elite allelopathic cultivars and the identification of the allelochemicals involved. Based on this, traditional breeding efforts were initiated in rice and wheat to breed agronomically acceptable, weed-suppressive cultivars with improved allelopathic interference. Promising suppressive crosses are under investigation. Molecular approaches have elucidated the genetics of allelopathy by QTL mapping which associated the trait in rice and wheat with several chromosomes and suggested the involvement of several allelochemicals. Potentially important compounds that are constitutively secreted from roots have been identified in all crop species under investigation. Biosynthesis and exudation of these metabolites follow a distinct temporal pattern and can be induced by biotic and abiotic factors. The current state of knowledge suggests that allelopathy involves fluctuating mixtures of allelochemicals and their metabolites as regulated by genotype and developmental stage of the producing plant, environment, cultivation and signalling effects, as well as the chemical or microbial turnover of compounds in the rhizosphere. Functional genomics is being applied to identify genes involved in biosynthesis of several identified allelochemicals, providing the potential to improve allelopathy by molecular breeding. The dynamics of crop allelopathy, inducible processes and plant signalling is gaining growing attention; however, future research should also consider allelochemical release mechanisms, persistence, selectivity and modes of action, as well as consequences of improved crop allelopathy on plant physiology, the environment and management strategies. Creation of weed-suppressive cultivars with improved allelopathic interference is still a challenge, but traditional breeding or biotechnology should pave the way.

PIC1, an ancient permease in Arabidopsis chloroplasts, mediates iron transport.

Abstract: In chloroplasts, the transition metals iron and copper play an essential role in photosynthetic electron transport and act as cofactors for superoxide dismutases. Iron is essential for chlorophyll biosynthesis, and ferritin clusters in plastids store iron during germination, development, and iron stress. Thus, plastidic homeostasis of transition metals, in particular of iron, is crucial for chloroplast as well as plant development. However, very little is known about iron uptake by chloroplasts. Arabidopsis thaliana PERMEASE IN CHLOROPLASTS1 (PIC1), identified in a screen for metal transporters in plastids, contains four predicted α-helices, is targeted to the inner envelope, and displays homology with cyanobacterial permease-like proteins. Knockout mutants of PIC1 grew only heterotrophically and were characterized by a chlorotic and dwarfish phenotype reminiscent of iron-deficient plants. Ultrastructural analysis of plastids revealed severely impaired chloroplast development and a striking increase in ferritin clusters. Besides upregulation of ferritin, pic1 mutants showed differential regulation of genes and proteins related to iron stress or transport, photosynthesis, and Fe-S cluster biogenesis. Furthermore, PIC1 and its cyanobacterial homolog mediated iron accumulation in an iron uptake–defective yeast mutant. These observations suggest that PIC1 functions in iron transport across the inner envelope of chloroplasts and hence in cellular metal homeostasis.

Soil Redox Potential: Importance, Field Measurements, and Observations

Abstract: Reduction and oxidation measurements create important data for analysis of wet soils. These measurements are actually recordings of voltage (EH) over time between a reference electrode and a sensor electrode inserted into a soil. The sensor electrodes are usually made of platinum wire (Pt electrode). Hydric soils require a period of reduction, and these measures can provide the length of time that the reduction process is occurring. The voltage results from an exchange of electrons between a redox couple such as ferrous and ferric iron during the process of reduction and oxidation. In soils that have fluctuating wet and dry conditions, wide fluctuations in Eh occur. Micro site differences complicate these measurements in that anaerobes may be active and at 1‐cm away they are completely inactive. The ferrous–ferric iron couple usually dominates these measurements but other couple often contributes complicating the measurements and interpretations of the data. Reference electrodes are often fine for laboratory work but are not rugged enough for the field. In this chapter, suggestions for improvement are discussed. Field‐measuring equipment and the Pt electrode are also sensitive and subject to problems that often lead to spurious results in the field. These problems are discussed at length. Iron‐coated tubes and other methods of establishing redox conditions are relatively recent and are discussed, also.

A cytosolic trans -activation domain essential for ammonium uptake

Abstract: Polytopic membrane proteins are essential for cellular uptake and release of nutrients. To prevent toxic accumulation, rapid shut-off mechanisms are required. Here we show that the soluble cytosolic carboxy terminus of an oligomeric ammonium transporter from Arabidopsis thaliana serves as an allosteric regulator essential for function; mutations in the C-terminal domain, conserved between bacteria, fungi and plants, led to loss of transport activity. When co-expressed with intact transporters, mutants inactivated functional subunits, but left their stability unaffected. Co-expression of two inactive transporters, one with a defective pore, the other with an ablated C terminus, reconstituted activity. The crystal structure of an Archaeoglobus fulgidus ammonium transporter (AMT) suggests that the C terminus interacts physically with cytosolic loops of the neighbouring subunit. Phosphorylation of conserved sites in the C terminus are proposed as the cognate control mechanism. Conformational coupling between monomers provides a mechanism for tight regulation, for increasing the dynamic range of sensing and memorizing prior events, and may be a general mechanism for transporter regulation.

Farmers and researchers: How can collaborative advantages be created in participatory research and technology development?

Abstract: This article examines differences in the research approaches of farmers and scientists and analyzes how these differences are related to the conditions under which both groups engage in experimental work. Theoretical considerations as well as practical experiences are presented to emphasize the great potential of farmer–researcher collaboration for rural innovation. In the first part of the article, the innovative power of farmer research and experimentation is acknowledged by presenting examples such as crop and animal breeding, development of new production systems, farm equipment, and social innovations. Considering the respective comparative advantages of farmers and scientists, and inspired by theoretical concepts in the fields of knowledge management and innovation processes, we discuss five topics for optimizing the collaboration between farmers and scientists in the field of technological innovation: user orientation, decentralization, informal modes of experimentation, externalization of tacit knowledge, and economic considerations. A better understanding of such issues could help researchers to define their own role in the research process, acknowledge the strengths and weaknesses of their own and farmers’ research approaches, overcome communication gaps, and find creative solutions for problems that typically occur in the process of participatory technology development.

Betalains – emerging prospects for food scientists

Abstract: Betalains have witnessed swayings of scientific interest in the past 40 years, but only during the past decade research activities in many disciplines dealing with breeding, phytochemical, technological and nutritional aspects have broadened the hitherto narrow view on betalains. The challenge of bringing together the knowledge from all these different fields of expertise is considered to be most fruitful. In the present review, the focus will be on the technologically related analytical issues.

Consensus meeting: monosodium glutamate – an update

Abstract: Update of the Hohenheim consensus on monosodium glutamate from 1997: Summary and evaluation of recent knowledge with respect to physiology and safety of monosodium glutamate. Experts from a range of relevant disciplines received and considered a series of questions related to aspects of the topic. University of Hohenheim, Stuttgart, Germany. The experts met and discussed the questions and arrived at a consensus. Total intake of glutamate from food in European countries is generally stable and ranged from 5 to 12 g/day (free: ca. 1 g, protein-bound: ca. 10 g, added as flavor: ca. 0.4 g). L-Glutamate (GLU) from all sources is mainly used as energy fuel in enterocytes. A maximum intake of 16.000 mg/kg body weight is regarded as safe. The general use of glutamate salts (monosodium-L-glutamate and others) as food additive can, thus, be regarded as harmless for the whole population. Even in unphysiologically high doses GLU will not trespass into fetal circulation. Further research work should, however, be done concerning the effects of high doses of a bolus supply at presence of an impaired blood brain barrier function. In situations with decreased appetite (e.g., elderly persons) palatability can be improved by low dose use of monosodium-L-glutamate.

Conventional and alternative processes for spice production – a review

Abstract: Conventional production of spices implicates a number of hygienic problems which can pose tremendous risks for farmers, producers and consumers. Furthermore, food quality may also be adversely affected. Only few conventional technologies exist for the sanitation of spices, however, some applications such as the fumigation with ethylene oxide are restricted and even banned by law in the European Union. As a consequence, there is a need for the development of innovative technologies for the production of high quality spices. This contribution summarizes the major problems associated with conventional spice production and provides a review of alternative technologies developed very recently.

Candidate pheromone receptors provide the basis for the response of distinct antennal neurons to pheromonal compounds.

Abstract: Males of the moth species Heliothis virescens are able to detect the female-released pheromone with remarkable sensitivity and specificity, distinguishing between highly related pheromonal compounds. In the past, electrophysiological studies succeeded in assigning sensory hairs to identified compounds revealing three functional types of long sensilla trichodea housing neurons specifically responding to distinct semiochemicals. The specific responsiveness implies that the sensory neurons express different receptor types tuned to pheromone components. In this study we demonstrate that heterologously expressed candidate pheromone receptors from Heliothis responded to several pheromonal compounds, including the major sex-pheromone component Z-11-hexadecenal indicating a limited specificity of each receptor type. Nonetheless, based on functional analysis and in situ hybridization studies the analysed receptor types could tentatively be assigned to types of long sensilla trichodea, containing the pheromone-binding proteins (PBPs) HvirPBP1 and HvirPBP2 in the sensillum lymph. Substituting organic solvent with PBPs to solubilize the hydrophobic pheromone compounds in functional assays revealed an increase in sensitivity and especially specificity. It was found that in the presence of HvirPBP2, cells expressing the receptor type HR13 specifically responded to the main component of the sex pheromone blend only. The data provide further evidence that a combination of a distinct receptor type and binding protein underlie the specific response observed in the detection of a pheromone component in vivo.