Sebastian P.,Johannes Gutenberg University Mainz |
Herr P.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Fischer U.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Konig H.,Johannes Gutenberg University Mainz
South African Journal of Enology and Viticulture | Year: 2011
A specifically amplified polymorphic DNA-polymerase chain reaction (SAPD-PCR), a molecular fingerprinting method based on the amplification of specific gene sequences, was applied in order to allow a rapid identification of lactic acid bacteria (LAB) occurring in must and wine. The applicability of this method was confirmed with isolated strains from different wine samples from the German wine growing region Palatinate. In addition, the formation of biogenic amines by the isolated strains was studied. More than half of the bacterial isolates from 50 red and white wine samples were able to produce biogenic amines. General health concerns related to biogenic amines in must and wine underline the need for an identification of these species. The majority of the isolated strains were assigned to the species Lactobacillus brevis. The major biogenic amines in the investigated wines which were detected by thin-layer chromatography and HPLC were tyramine, histamine and ethylamine.
Rossberg D.,Julius Kuhn Institute |
Ipach R.,Dienstleistungszentrum landlicher Raum Rheinpfalz
Journal fur Kulturpflanzen | Year: 2015
Freely available information on the actual use of chemical plant protection products (PPPs) in agriculture is highly necessary for a number of scientific questions and political discussion. Therefore, since 2000, regular surveys on the use of PPPs have been carried out for the most important agricultural and horticultural crops in Germany (NEPTUN projects). In 2011, they were adjusted to legal framework changes. Since then they are known as PAPA surveys with “PAPA” being an abbreviation for Panel Pesticide Applications. For each crop a network of farms was built up. In each the PPP application data are collected annually. The participating farms are distributed throughout Germany proportionally to the production area per crop. The data was anonymized and forwarded to the Julius Kühn-Institut (JKI). All surveys and analyses based on the panel refer to the Federal Republic of Germany. The results of PAPA surveys show that in grape the plant protection intensity has increased steadily in recent years. One reason for this development is a considerable increase in fungal pathogens in permanent crop sites (especially in viticulture). In addition, an increase of “new” pathogens was observed. Both may be a consequence of climate change/global warming. Finally, the ban of some highly effective pesticides and the development of resistances lead to an increase in pesticide applications. Therefore, a reduction of chemical plant protection measures cannot be expected in the next few years. © 2015, Verlag Eugen Ulmer. All rights reserved.
Han M.,University of Heidelberg |
Heppel S.C.,University of Heidelberg |
Su T.,University of Heidelberg |
Bogs J.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
And 3 more authors.
PLoS ONE | Year: 2013
In Catharanthus roseus, the monoterpene moiety exerts a strong flux control for monoterpene indole alkaloid (MIA) formation. Monoterpene synthesis depends on the methyl-D-erythritol 4-phosphate (MEP) pathway. Here, we have explored the regulation of this pathway in response to developmental and environmental cues and in response to specific enzyme inhibitors. For the MEP pathway entry enzyme 1-deoxy-D-xylulose 5-phosphate synthase (DXS), a new (type I) DXS isoform, CrDXS1, has been cloned, which, in contrast to previous reports on type II CrDXS, was not transcriptionally activated by the transcription factor ORCA3. Regulation of the MEP pathway in response to metabolic perturbations has been explored using the enzyme inhibitors clomazone (precursor of 5-ketochlomazone, inhibitor of DXS) and fosmidomycin (inhibitor of deoxyxylulose 5-phosphate reductoisomerase (DXR)), respectively. Young leaves of non-flowering plants were exposed to both inhibitors, adopting a non-invasive in vivo technique. Transcripts and proteins of DXS (3 isoforms), DXR, and hydroxymethylbutenyl diphosphate synthase (HDS) were monitored, and protein stability was followed in isolated chloroplasts. Transcripts for DXS1 were repressed by both inhibitors, whereas transcripts for DXS2A&B, DXR and HDS increased after clomazone treatment but were barely affected by fosmidomycin treatment. DXS protein accumulated in response to both inhibitors, whereas DXR and HDS proteins were less affected. Fosmidomycin-induced accumulation of DXS protein indicated substantial posttranscriptional regulation. Furthermore, fosmidomycin effectively protected DXR against degradation in planta and in isolated chloroplasts. Thus our results suggest that DXR protein stability may be affected by substrate binding. In summary, the present results provide novel insight into the regulation of DXS expression in C. roseus in response to MEP-pathway perturbation. © 2013 Han et al.
Schmarr H.-G.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Schmarr H.-G.,TU Munich |
Engel K.-H.,TU Munich
European Food Research and Technology | Year: 2012
Contents and enantiomeric distributions of linalool (3,7-dimethyl-1,6-octadien-3-ol) were investigated in raw and roasted cocoa beans (seeds of Theobroma cacao) of defined origin as well as in commercial products, such as cocoa powders or chocolates. The stereodifferentiation of linalool was achieved by enantioselective multidimensional gas chromatography using heptakis (2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin as chiral stationary phase. Simultaneous steam distillation-extraction at pH 7 allowed sample preparation without racemization of linalool. Cocoa beans contain linalool primarily as (S)-enantiomer. Model experiments and analyses of commercial products such as cocoa powders and chocolates revealed that technological procedures employed in the manufacturing of cocoa products do not result in significant changes of the original enantiomeric distribution of linalool. © 2012 Springer-Verlag.
Becker T.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Knoche M.,Leibniz University of Hanover
Vitis - Journal of Grapevine Research | Year: 2012
The objectives of this study were to quantify deposition, strain, and microcracking of the cuticular membrane (CM) in developing 'Riesling' (Vitis vinifera L.) berries. Mass of the CM, the cutin matrix (DCM), and wax increased pre-veraison (26 to 65 days after anthesis, DAA) on a berry (+ 236, + 211, and + 332 %, respectively) and a surface area basis (+ 11, + 3, and + 43 %, respectively). Post-veraison (65 to 138 DAA), CM and DCM mass per berry remained about constant at 3.4 (± 0.16) and 2.4 (± 0.11) mg per berry, respectively, while wax mass continued to increase from 0.8 (± 0.02) to 1.1 (± 0.02) mg per berry. On an area basis, however, CM and cutin mass decreased from 5.0 (± 0.13) to 4.6 (± 0.04) g·m -2 and from 3.5 (± 0.10) to 3.2 (± 0.03) g·m -2 between 65 and 138 DAA, respectively, but wax mass remained constant at about 1.5 (± 0.04) g·m -2. The calculated rate of cutin and wax deposition peaked at about 40 DAA, and declined continuously thereafter. There was no strain and no microcracking of the CM up to veraison. Post-veraison strain of the CM and microcracking in the stylar scar region increased linearly with time. The data suggest that the cessation of cutin deposition in post-veraison berries and the ongoing berry expansion resulted in increased strain of the CM which in turn caused microcracking in the CM.
Rossberg D.,Julius Kuhn Institute |
Harzer U.,Dienstleistungszentrum landlicher Raum Rheinpfalz
Journal fur Kulturpflanzen | Year: 2015
Surveys of the application of plant protection products (PPP) in apple farming have been carried out since 2001 (NEPTUN projects). Since 2011, they have been continued under different legislative frameworks as PAPA surveys. PAPA stands for panel pesticide applications. A number of crop-specific networks of farms have been created, in which the PPP application data are recorded in detail annually. The data are forwarded in an anonymised form to the Julius Kühn-Institute (JKI). All surveys and analyses relate to the Federal Republic of Germany. The distribution of the panel farms was proportional to the distribution of growing areas of apples. Survey results show that the plant protection intensity has established itself in apple growing for years at a constant level. A reduction in the number of chemical plant protection measures are not expected in the coming years. The increasing incidence of new invasive pests and the expected lower availability of insecticidal agents (associated with an increased risk of resistance) probably require more additional applications of chemical pesticides to produce apples in sufficient quantity and of marketable quality. © 2015, Verlag Eugen Ulmer. All rights reserved.
Balmer M.,Dienstleistungszentrum Landlicher Raum Rheinpfalz
Erwerbs-Obstbau | Year: 2015
On a study visit to the south-east and south of Australia in December 2014, fruit farmers got an impression of the Australian sweet cherry production. The cultivation is export oriented, requiring high standards of sorting, packing and freshness. Large production units, low tree forms such as the Spanish bush or Kym-Green Bush and a high level of automation for sorting and packing help to reduce costs despite of high wages. Through closer proximity to major customers in East Asia compared to the Chilean competitor and the use of air freight prices can be realized, which make production economically. © 2015, Springer-Verlag Berlin Heidelberg.
Schmarr H.-G.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Slabizki P.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Legrum C.,Dienstleistungszentrum Landlicher Raum Rheinpfalz |
Legrum C.,University of Kaiserslautern
Analytical and Bioanalytical Chemistry | Year: 2013
Trace level analyses in complex matrices benefit from heart-cut multidimensional gas chromatographic (MDGC) separations and quantification via a stable isotope dilution assay. Minimization of the potential transfer of co-eluting matrix compounds from the first dimension (1D) separation into the second dimension separation requests narrow cut-windows. Knowledge about the nature of the isotope effect in the separation of labeled and unlabeled compounds allows choosing conditions resulting in at best a co-elution situation in the 1D separation. Since the isotope effect strongly depends on the interactions of the analytes with the stationary phase, an appropriate separation column polarity is mandatory for an isotopic co-elution. With 3-alkyl-2-methoxypyrazines and an ionic liquid stationary phase as an example, optimization of the MDGC method is demonstrated and critical aspects of narrow cut-window definition are discussed. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg.
Hoss S.,Ecossa |
Hoss S.,Institute For Biodiversitat Netzwerk Ibn |
Menzel R.,Humboldt University of Berlin |
Gessler F.,University of Gottingen |
And 4 more authors.
Environmental Pollution | Year: 2013
The genetically modified maize MON89034 × MON88017 expresses different crystal (Cry) proteins with pesticidal activity against the European corn borer (Cry1.105; Cry2Ab2) and the Western corn root worm (Cry3Bb1). Non-target organisms, such as soil nematodes, might be exposed to the Cry proteins that enter the soil in course of crop growing. Therefore, the risk of those proteins for nematodes was assessed by testing their toxic effects on Caenorhabditis elegans. All three insecticidal Cry proteins showed dose-dependent inhibitory effects on C. elegans reproduction (EC50: 0.12-0.38 μmol L-1), however, at concentrations that were far above the expected soil concentrations. Moreover, a reduced toxicity was observed when Cry proteins were added jointly. A C. elegans mutant strain deficient for receptors for the nematicidal Cry5B was also resistant against Cry1.105 and Cry2Ab2, suggesting that these Cry proteins bound to the same or similar receptors as nematicidal Cry proteins and thereby affect the reproduction of C. elegans. © 2013 Elsevier Ltd. All rights reserved.
Walter R.,Dienstleistungszentrum Landlicher Raum Rheinpfalz
Journal fur Kulturpflanzen | Year: 2012
Botrytis cinerea (grey mould), Penicillium spec. (blue mould) and yeasts causing sour rot are the most important bunch rot pathogens in German vine growing regions. Penicillium species involved in rot of grapes produce secondary metabolites with significant impact on quality of must or wine and also on food safety. P. expansum, for instance, is the causal agent of blue mould on grapes and produces the volatile compound geosmin. Unfortunately, even a low level of geosmin may lead to a persistent earthy and musty smell of the wine. The role and biological function of geosmin and other secondary metabolites as well as environmental factors that may trigger their production are currently investigated. The project is supported by the German Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) through the Federal Office for Agriculture and Food (BLE 2810HS016). In contrast to the pathogen B. cinerea that may infect grape berries via wounds or by a direct penetration of the berry skin, P. expansum and sour rot pathogens are addicted solely to wounds for infection. Until now, there are no fungicides available that are effective against Penicillium spec. or sour rot pathogens on grapes. Therefore, control strategies mainly consider cultivation methods that help to avoid wounds on the berries. Different methods are used to change bunch structure in case for those grape varieties exhibiting an unfavourable compact bunch architecture. Among them, especially horizontal bunch dividing, hand stripping of berry rudiments, and the application of growth regulators are the most effective strategies to avoid wounds on berries and also infections leading to bunch rot.