Separation of olive proteins combining a simple extraction method and a selective capillary electrophoresis (CE) approach: application to raw and table olive samples     

Montealegre C  Marina ML  García-Ruiz C 《Journal of agricultural and food chemistry》2010,58(22):11808-11813

A simple extraction method was developed to extract proteins from olive samples based on chloroform/methanol extraction followed by a protein precipitation with cold acetone. Then, a capillary electrophoresis (CE) method was carried out using an acid buffer (1 M formic acid at pH 2) to ensure a positive net charge for proteins and a neutral charge for potential interferents as polyphenols. The method developed was applied to raw and table olive samples. Interestingly, raw olive samples showed differences in protein profiles depending upon the botanical variety of olives and their geographical region. Protein profiles obtained for table olives also showed differences according to the sample treatment. Thus, a signal reduction in the electropherograms obtained for black olives was observed in comparison to those achieved for treated green olives. In this work, the use of protein profiles was demonstrated to be a powerful tool for studying variations among olive samples.  相似文献   

Indirect host effect on ectomycorrhizal fungi: Leaf fall and litter quality explain changes in fungal communities on the roots of co-occurring Mediterranean oaks     

Cristina Aponte  Luis V. García  Monique Gardes 《Soil biology & biochemistry》2010,42(5):788-796

Host trees can modify their soil abiotic conditions through their leaf fall quality which in turn may influence the ectomycorrhizal (ECM) fungal community composition. We investigated this indirect interaction using a causal modelling approach. We identified ECM fungi on the roots of two coexisting oak species growing in two forests in southern Spain - Quercus suber (evergreen) and Quercus canariensis (winter deciduous)-using a PCR-based molecular method. We also analysed the leaf fall, litter and soil sampled beneath the tree canopies to determine the concentrations of key nutrients. The total mycorrhizal pool was comprised of 69 operational taxonomic units (OTUs). Tomentella and Russula were the most species-rich, frequent and abundant genera. ECM fungi with epigeous and resupinate fruiting bodies were found in 60% and 34% of the identified mycorrhizas, respectively. The calcium content of litter, which was significantly higher beneath the winter-deciduous oak species due to differences in leaf fall quality, was the most important variable for explaining ECM species distribution. The evaluation of alternative causal models by the d-sep method revealed that only those considering indirect leaf fall-mediated host effects statistically matched the observed covariation patterns between host, environment (litter, topsoil, subsoil) and fungal community variables.  相似文献   

First indications for the involvement of strigolactones on nodule formation in alfalfa (Medicago sativa)     

María J. Soto 《Soil biology & biochemistry》2010,42(2):383-15743

Strigolactones have recently been suggested to be phytohormones that are present in all plants. Strigolactones are released by roots into the rhizosphere, stimulating the seed germination of parasitic plants such as Striga spp. and Orobanche spp. and play a crucial role in the interaction between plants and symbiotic arbuscular mycorrhizal fungi.By applying different concentrations of the synthetic strigolactone analogue GR24 to alfalfa (Medicago sativa) inoculated with Sinorhizobium meliloti we could show that in alfalfa nodulation is positively affected by the presence of the strigolactone analogue GR24. Moreover, we could show that this increased nodulation cannot be linked with a stimulatory effect of GR24 on the growth or the expression of nod genes of S. meliloti.Putative mechanisms operating in the plant in response to the addition of GR24 and leading to increased nodule formation by rhizobia are discussed.  相似文献   

Emissions of CO₂, CH₄ and N₂O from Southern European peatlands     

Tjaša Danev?i?  Bla? Stres  David Stopar  Janez Hacin 《Soil biology & biochemistry》2010,42(9):1437-1446

Peatlands play an important role in emissions of the greenhouse gases CO₂, CH₄ and N₂O, which are produced during mineralization of the peat organic matter. To examine the influence of soil type (fen, bog soil) and environmental factors (temperature, groundwater level), emission of CO₂, CH₄ and N₂O and soil temperature and groundwater level were measured weekly or biweekly in loco over a one-year period at four sites located in Ljubljana Marsh, Slovenia using the static chamber technique. The study involved two fen and two bog soils differing in organic carbon and nitrogen content, pH, bulk density, water holding capacity and groundwater level. The lowest CO₂ fluxes occurred during the winter, fluxes of N₂O were highest during summer and early spring (February, March) and fluxes of CH₄ were highest during autumn. The temporal variation in CO₂ fluxes could be explained by seasonal temperature variations, whereas CH₄ and N₂O fluxes could be correlated to groundwater level and soil carbon content. The experimental sites were net sources of measured greenhouse gases except for the drained bog site, which was a net sink of CH₄. The mean fluxes of CO₂ ranged between 139 mg m⁻² h⁻¹ in the undrained bog and 206 mg m⁻² h⁻¹ in the drained fen; mean fluxes of CH₄ were between −0.04 mg m⁻² h⁻¹ in the drained bog and 0.05 mg m⁻² h⁻¹ in the drained fen; and mean fluxes of N₂O were between 0.43 mg m⁻² h⁻¹ in the drained fen and 1.03 mg m⁻² h⁻¹ in the drained bog. These results indicate that the examined peatlands emit similar amounts of CO₂ and CH₄ to peatlands in Central and Northern Europe and significantly higher amounts of N₂O.  相似文献   

Heavy Metal and Nitrogen Monitoring Using Moss and Topsoil Samples in a Pyrenean Forest Catchment     

L. González-Miqueo  D. Elustondo  E. Lasheras  R. Bermejo  J. M. Santamaría 《Water, air, and soil pollution》2010,210(1-4):335-346

This study was carried out in order to assess both the deposition of heavy metal and nitrogen in a mountain ecosystem with low levels of metal deposition and its possible interactions with factors such as lithology and topography. For this purpose, samples of Hypnum cupressiforme Hedw. and topsoils were collected in a forest catchment within Bertiz Natural Park, an International Cooperative Programme on Integrated Monitoring site. Trace metals levels in mosses can be considered low compared with values reported elsewhere in Europe, and the dust soil mineral particles seemed to be the main source of these values. Only Cd and Hg presented external inputs, probably with an anthropic origin, for mosses according to the enrichment factor values, whereas historical pollution-related deposition in soils was determined for Pb, Cu, and Ni, attending to their total/extractable ratio.  相似文献   

Bioaccumulation of Copper by Zea mays: Impact on Root, Shoot and Leaf Growth     

Claudia S. Benimeli  Analía Medina  Carolina M. Navarro  Roxana B. Medina  María J. Amoroso  María I. Gómez 《Water, air, and soil pollution》2010,210(1-4):365-370

In the present study, the growth and the Cu²⁺accumulation by roots, shoots and leaves of Zea mays were examined using copper sulphate in the range of 10^?4 to 10^?2 M. Plants of Z. mays did not show inhibition of growth in the presence of 10^?4 to 10^?2 M Cu²⁺; however, it was observed growth effects on root when different Cu²⁺ solution concentrations were used. Only the seedlings exposed to 10^?2 M exhibited substantial root growth reduction, yielding only 56% of length with respect to the control. Seedlings exposed to 10^?4 M Cu²⁺ exhibited 16% and 42% growth increase in shoots and leaves, respectively, when compared with the controls. The seedlings treated with 10^?3 and 10^?2 M Cu²⁺ were inhibited in shoot and leaf growth. The fresh weights in roots, shoots and leaves significantly decreased at 10^?2 M Cu²⁺. The tolerance index, based on root length, was not significantly different for the three different treatments with copper. However, the total accumulation rate was very low at 10^?4 and 10^?3 M compared to 10^?2 Cu treatments. The capacity of copper accumulation by roots, shoots and leaves of Z. mays plants increased concomitant to the copper concentration, arriving to 382 times more in roots, 157 in shoots and only 16 in leaves, all compared to the controls. Cu could be accumulated by roots, shoots and leaves when the initial concentrations were 10^?3 and 10^?4 M. However, when it was 10^?2 M, the metal could not be accumulated by leaf and shoot levels; the roots could increase their copper accumulation capacity three times compared to the control. Z. mays has potential ability to accumulate Cu without being overly sensitive to Cu toxicity.  相似文献   

Bioaccumulation and Effects of Heavy Metals in Crayfish: A Review     

Antonín Kouba  Miloš Buřič  Pavel Kozák 《Water, air, and soil pollution》2010,211(1-4):5-16

Metal pollution is a global problem which represents a growing threat to the environment. Because of bioaccumulation and negative effects of heavy metals, their bioavailability needs to be monitored. Many studies showed accumulation of metals in crayfish tissues as dose- and time-dependent without significant differences in tissue concentration levels comparing males and females. Muscles and exoskeleton were considered as specific for accumulation of mercury and nickel, respectively. Cadmium, zinc, copper, lead, and chromium accumulated mainly in hepatopancreas. By analyzing these specific tissues, it is possible to deduce the bioavailability and, by presumption, the level of environmental pollution by specific metals. However, in the case of zinc and copper, their utility is limited to assessing bioavailability because rapid depuration of these metals renders them less useful for long-term environmental monitoring programs. The literature reporting heavy metal impacts on freshwater crayfish, with reference to accumulation levels, is reviewed and summarized with respect to their suitability as bioindicators. Summarized published data from unpolluted or control localities can be used as referential values in crayfish, and consequently help with evaluation of monitored sites.  相似文献   

Influence of Salinity in the Bioavailability of Zn in Sediments of the Gulf of Cádiz (Spain)     

Inmaculada Riba  Enrique García-Luque  Alejandra Maz-Courrau  María Luisa González de Canales  Tomás Ángel DelValls 《Water, air, and soil pollution》2010,212(1-4):329-336

This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K _D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease.  相似文献   

In Situ Heavy Metal Accumulation in Lettuce Growing Near a Former Mining Waste Disposal Area: Implications for Agricultural Management     

Héctor M. Conesa  Jose A. Pérez-Chacón  Raquel Arnaldos  Joaquín Moreno-Caselles  Ángel Faz-Cano 《Water, air, and soil pollution》2010,208(1-4):377-383

Mining wastes may pose risk nearby urban and agricultural areas. We investigated a lettuce crop land close to a former capped mine tailing in order to determinate the metal uptake by crops. Soil plot sampling design within the crop area and two transects along the tailing were performed. In addition, lettuces (root and leaves) were analyzed after transplant and harvest. The results showed a pH of around 7–8 for all the soil samples. Total metal concentrations were as follows: 190–510 mg kg^?1 Pb, 13–21 mg kg^?1 Cu, and 210–910 mg kg^?1 Zn. Diethylene triamine pentaacetic acid-extractable Pb was around 18% of the total Pb in some samples. Transects along the base and on the plateau of the tailing showed high metal concentrations of Pb (up to 5,800 mg kg^?1) and Zn (up to 4,500 mg kg^?1), indicating that capping layer had been eroded. Lettuce leaves showed Pb concentrations within standard for human health (<0.3 mg kg^?1 in fresh weight). For essential micronutrients such as Cu and Zn, leaves had optimal content (10–28 mg kg^?1 Cu, 60–85 mg kg^?1 Zn). A continued monitoring in metal uptake is needed in crop lands close to mining wastes in order to prevent risks in food safety. Capped tailings must be monitored and rehabilitation works performed from time to time.  相似文献   

Does Dietary Administration of Lactococcus lactis Modulate the Gut Microbiota of Grouper,Epinephelus coioides     

Yun‐Zhang Sun  Hong‐Ling Yang  Ru‐Long Ma  Shao‐Wei Zhai 《Journal of the World Aquaculture Society》2012,43(2):198-207

The effect of dietary administration of probiotic Lactococcus lactis MM1 for 60 d on the autochthonous microbiota in the foregut, midgut and hindgut of juvenile grouper, Epinephelus coioides, was evaluated using polymerase chain reaction‐denaturing gradient gel electrophoresis (DGGE). Samples collected from the probiotic and control groups showed different DGGE patterns, while 11 common bands presented in both groups. The similarity dendrogram revealed three different clusters depending on the three sections of the gastrointestinal (GI) tract, and the probiotic triplicates in each GI section were generally clustered into one group distinctly different from the corresponding control triplicates. Increased species richness and Shannon index were observed in the foregut, midgut, and hindgut samples in the probiotic group compared with the control group, which suggested that probiotic L. lactis MM1 could improve the autochthonous microbial diversity along the GI tract of E. coioides. The growth of many potentially beneficial and unidentified bacteria was stimulated by the probiotic, whereas the growth of some potential harmful species, like Staphylococcus saprophyticus, was depressed.  相似文献