Phosphorus speciation of forest‐soil organic surface layers using P K‐edge XANES spectroscopy     

Jörg Prietzel  Jürgen Thieme  David Paterson 《植物养料与土壤学杂志》2010,173(6):805-807

The phosphorus (P) speciation of organic surface layers from two adjacent German forest soils with different degree of water‐logging (Stagnosol, Rheic Histosol) was analyzed by P K‐edge XANES and subsequent Linear Combination Fitting. In both soils, ≈ 70% of the P was inorganic phosphate and ≈ 30% organic phosphate; reduced P forms such as phosphonate were absent. The increased degree of water‐logging in the Histosol compared to the Stagnosol did not affect P speciation.  相似文献   

Effects of Aporrectodea caliginosa (Savigny) on nitrogen mobilization and decomposition of elevated‐CO2 Charlock mustard litter     

Sven Marhan  Franziska Rempt  Petra Högy  Andreas Fangmeier  Ellen Kandeler 《植物养料与土壤学杂志》2010,173(6):861-868

This study was conducted to improve our understanding of how earthworms and microorganisms interact in the decomposition of litter of low quality (high C : N ratio) grown under elevated atmospheric [CO₂]. A microcosm approach was used to investigate the influence of endogeic earthworm (Aporrectodea caliginosa Savigny) activity on the decomposition of senescent Charlock mustard (Sinapis arvensis L.) litter produced under ambient and elevated [CO₂]. Earthworms and microorganisms were exposed to litter which had changed in quality (C : N ratio) while growing under elevated [CO₂]. After 50 d of incubation in microcosms, C mineralization (CO₂ production) in the treatment with elevated‐[CO₂] litter was significantly lower in comparison to the ambient‐[CO₂] litter treatment. The input of Charlock mustard litter into the soil generally induced N immobilization and reduced N₂O‐emission rates from soil. Earthworm activity enhanced CO₂ production, but there was no relationship to litter quality. Although earthworm biomass was not affected by the lower quality of the elevated‐[CO₂] litter, soil microbial biomass (C_mic, N_mic) was significantly decreased. Earthworms reduced C_mic and fungal biomass, the latter only in treatments without litter. Our study clearly showed that A. caliginosa used the litter grown under different [CO₂] independent of its quality and that their effect on the litter‐decomposition process was also independent of litter quality. Soil microorganisms were shown to negatively react to small changes in Charlock mustard litter quality; therefore we expect that microbially mediated C and N cycling may change under future atmospheric [CO₂].  相似文献   

Chronic toxicity of contaminated sediments on reproduction and histopathology of the crustacean <Emphasis Type="Italic">Gammarus fossarum</Emphasis> and relationship with the chemical contamination and in vitro effects     

Edita Mazurová  Klára Hilscherová  Tereza Šídlová-Štěpánková  Heinz-R. Köhler  Rita Triebskorn  Dirk Jungmann  John P. Giesy 《Journal of Soils and Sediments》2010,10(3):423-433

Purpose  

The aim of the present study was to investigate possible relationships between the sediment contaminants and the occurrence of intersex in situ. Two of the studied sediments were from polluted sites with increased occurrence of intersex crustaceans (Lake Pilnok, black coal mining area in the Czech Republic, inhabited by the crayfish Pontastacus leptodactylus population with 18% of intersex; creek Lockwitzbach in Germany with Gammarus fossarum population with about 7% of intersex).  相似文献   

Looking back to 2009 and ahead to 2010     

Almut B. Heinrich  Ulrich Förstner 《Journal of Soils and Sediments》2010,10(1):1-3

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Sediments and the “System”: from site-specific to regional-scale research     

Wim Salomons  Ulrich Förstner 《Journal of Soils and Sediments》2010,10(8):1436-1439

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Bioaccumulation of ivermectin from natural and artificial sediments in the benthic organism <Emphasis Type="Italic">Lumbriculus variegatus</Emphasis>     

Tineke Slootweg  Michel Alvinerie  Philipp Egeler  Daniel Gilberg  Jussi V. K. Kukkonen  Jörg Oehlmann  Carsten Prasse  Arto J. Sormunen  Markus Liebig 《Journal of Soils and Sediments》2010,10(8):1611-1622

Purpose  

Although ivermectin is a widely used lipophilic parasiticide, data on its potential bioaccumulation in aquatic invertebrates are scarce. In this study, bioaccumulation patterns of radiolabeled ³H-ivermectin from sediments into tissues of the sediment-dwelling worm Lumbriculus variegatus were investigated and assessed.  相似文献   

Arbuscular mycorrhizal association is beneficial for growth and detoxification of xenobiotics of barley under drought stress     

Mohammadali Khalvati  Bernadett Bartha  Arthur Dupigny  Peter Schröder 《Journal of Soils and Sediments》2010,10(1):54-64

Background, aim, and scope  

Plant growth and productivity under abiotic stresses such as water shortage or pollution are major problems which currently worry scientists in the field of food production and plant health. Since the intensification of livestock production with its associated increased demand for fodder has encouraged farmers to rely more heavily on chemical fertilizers, very often, municipal waste and wastewater sludge is considered a possible source of plant nutrients, although it might carry a significant amount of anthropogeneous pollutants. The extent to which plants react to drought, as well as how pollutants are taken up or how they act on plants, might depend on rhizosphere processes such as mycorrhizal symbioses. Therefore, it seemed timely to investigate plant defense reactions in the presence of arbuscular mycorrhizal fungi (AMF) toward a possible dangerous sewage sludge pollutant under the influence of drought.  相似文献   

Compositions and antimicrobial activities of the essential oils of two Hypericum species from Turkey     

Toker Z  Kizil G  Ozen HC  Kizil M  Ertekin S 《Fitoterapia》2006,77(1):57-60

The chemical compositions of essential oils obtained from Hypericum hyssopifolium var. microcalycinum and Hypericum lysimachioides var. lysimachioides were analysed by using GC and GC-MS. Caryophyllene oxide was found to be the major component. The essential oils of both Hypericum species showed antimicrobial activity against nine microorganism at a concentration of 60 to 80 microg/ml.  相似文献   

Odor thresholds of microbially induced off-flavor compounds in apple juice     

Siegmund B  Pöllinger-Zierler B 《Journal of agricultural and food chemistry》2006,54(16):5984-5989

Microbially derived off-flavor is a major problem in apple juice production as it diminishes the sensory quality of the juice significantly. Fifteen relevant off-flavor compounds that are formed in apple juice, for example, by the strains Alicyclobacillus acidoterrestris and Actinomycetes (Streptomyces ssp.) were investigated with respect to their sensory relevance. The odor threshold values (i.e., detection and recognition values) were determined for all compounds in the matrix apple juice. Odor threshold values for fenchyl alcohol are reported here for the first time. The obtained values were set in relation to the limits of detection and quantification of a previously published GC-MS method. Eight tainted apple juice samples were analyzed for the presence of the 2 strains and the 15 off-flavor compounds. Both strains could be found in the samples; the presence of Streptomyces ssp. as spoilage bacteria of apple juice is reported for the first time. In samples with distinct off-flavor, 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 2-methylisoborneol, 1-octen-3-ol, fenchyl alcohol, geosmin, and guaiacol as well as 2,6-dibromophenol were determined in concentrations higher than the detection threshold.  相似文献   

Salt-induced changes in pork myofibrillar tissue investigated by FT-IR microspectroscopy and light microscopy     

Böcker U  Ofstad R  Bertram HC  Egelandsdal B  Kohler A 《Journal of agricultural and food chemistry》2006,54(18):6733-6740

FT-IR microspectroscopy and light microscopy were used to investigate pork muscle musculus semitendinosus samples, taken from three animals, that were subjected to brine salting at different concentrations (0.9, 3, 6, and 9% NaCl). Differences in spectral characteristics and in microstructure were observed in meat from animals differing in initial pH and varying salt concentrations. The FT-IR data displayed changes in the amide I region from 1700 to 1600 cm(-1). This spectral range was analyzed by principal component analysis (PCA) and partial least-squares regression (PLSR). These methods revealed correlations between the spectral data and the different animals, salt content, moisture content, pH value, and myofiber diameter. A shrinking share of alpha-helical components was related to an increase in salt concentration in the muscle. At the same time, a greater share in nonhydrogenated C=O groups (1668 cm(-1)) was related to an increase in salt concentration in the meat. The share of aggregated beta-strands differed with respect to the different animals but was not influenced by salt concentration. The meat at higher pHs (>6) had less aggregated beta-strands than that at lower pHs (5.6-5.7). It could be demonstrated that simultaneous with changes in microstructure, pH value, salt, and moisture content were alterations in the protein amide I region as measured by FT-IR microspectroscopy, revealing a relationship between these biophysical and chemical parameters and secondary protein structure attributes.  相似文献