首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The nutrient composition of 15 commercially available microalgae powders of Arthrospira platensis, Chlorella pyrenoidosa and vulgaris, Dunaliella salina, Haematococcus pluvialis, Tetraselmis chuii, and Aphanizomenon flos-aquae was analyzed. The Dunaliella salina powders were characterized by a high content of carbohydrates, saturated fatty acids (SFAs), omega-6-polyunsaturated fatty acids (n6-PUFAs), heavy metals, and α-tocopherol, whereas the protein amounts, essential amino acids (EAAs), omega-3-PUFAs (n3-PUFAs), vitamins, and minerals were low. In the powder of Haematococcus pluvialis, ten times higher amounts of carotenoids compared to all other analyzed powders were determined, yet it was low in vitamins D and E, protein, and EAAs, and the n6/n3-PUFAs ratio was comparably high. Vitamin B12, quantified as cobalamin, was below 0.02 mg/100 g dry weight (d.w.) in all studied powders. Based on our analysis, microalgae such as Aphanizomenon and Chlorella may contribute to an adequate intake of critical nutrients such as protein with a high content of EAAs, dietary fibers, n3-PUFAs, Ca, Fe, Mg, and Zn, as well as vitamin D and E. Yet, the nutritional value of Aphanizomenon flos-aquae was slightly decreased by high contents of SFAs. The present data show that microalgae are rich in valuable nutrients, but the macro- and micronutrient profiles differ strongly between and within species.  相似文献   

2.
Low level of iron in staple food crops is one reason for the predominance of iron-deficiency anemia in developing countries. Most of the iron in rice grains accumulates in the outer aleurone layer and embryo, which are removed during milling, and the edible endosperm contains very low amounts of iron. In an effort to increase iron nutrition, we report here the transgene introgression of a high-iron trait into a high-yielding indica rice cultivar. The ferritin gene from soybean (soyfer1) was introduced into rice plants through interbreeding between soybean ferritin-overexpressing transgenic IR68144 and the high-yielding cultivar Swarna. The stable integration of the soyfer1 gene was confirmed in the BC2F4 generation, and the hybrid seeds showed 2.6-fold soybean ferritin gene expression over the recurrent parent Swarna. The hybrid milled seeds revealed a 2.54-fold increase in iron and 1.54-fold increase in zinc compared to Swarna. Agronomic data and an SSR marker analysis of the hybrid rice plants were taken into account for NIL character identification.  相似文献   

3.
L.JOJEE  D.MADONNA 《水稻科学》2010,17(4):257-268
Genetic diversity of 36 rice entries from the United States Department of Agriculture(USDA)rice collection was assessed using 103 ILP(intron length polymorphism)and 54 SSR(simple sequence repeats)markers.A total of 236 and 332 alleles were detected by the ILP and SSR markers,respectively.On average,the SSR markers produced higher polymorphism information content value and number of alleles than the ILP markers.Whereas the Nei's genetic distance measured using the SSR markers was much higher than that measured using the ILP markers.Mantel's test indicated that there was a statistically significant correlation(r=0.827,P0.001)between the two marker systems.UPGMA clustering based on the ILP and SSR markers resulted in consensus dendrograms.The cophenetic correlation coefficient(r=0.918,0.878 and 0.924,P0.001 for the ILP,SSR and combined markers,respectively)showed a highly accurate dendrogram represented the genetic distance among these entries.The 36 entries were divided into four groups.Four African Oryza glaberrima accessions were clustered within a distinct group(Ⅰ),and the remaining entries were separated into three groups(Ⅱ,Ⅲ and IV).All the entries could be also clustered into two main groups:One was composed of Ⅲ and IV,considered as indica group, and the other was composed of Ⅰ(O.glaberrima)and Ⅱ(japonica-like).Model-based cluster analysis revealed that the japonica-like group maintained very pure ancestry while the indica group shared mixed ancestry,especially for group Ⅲ, which had seven admixtures sharing from 19.5%to 30.0%of ancestry with group Ⅳ(based on SSR markers).It is suggested that ILP and SSR markers could be very useful for the genetic study and breeding in rice.  相似文献   

4.
Iron, as inorganic ion or as oxide, is widely used by biological systems in a myriad of biological functions (e.g., enzymatic, gene activation and/or regulation). In particular, marine organisms containing silica structures—diatoms and sponges—grow preferentially in the presence of iron. Using primary sponge cell culture from S. domuncula–primmorphs—as an in vitro model to study the Demospongiae spiculogenesis, we found the presence of agglomerates 50 nm in diameter exclusively inside sponge specialized cells called sclerocytes. A clear phase/material separation is observed between the agglomerates and the initial stages of intracellular spicule formation. STEM-HRTEM-EDX analysis of the agglomerates (30–100 nm) showed that they are composed of pseudohexagonal nanoparticles between 5 and 15 nm in size, displaying lattice parameters corresponding to hematite (Fe2O3) and mixed iron oxide phases typically attributed to ferritin. Further analysis, using western blotting, inductively coupled plasma mass spectrometry (ICP-MS), sequence alignment analysis, immunostaining and magnetic resonance imaging (MRI), of mature spicule filaments confirm the presence of ferritin within these organic structures. We suggest that S. domuncula can be classified as a dual biomineralizating organism, i.e., within the same cellular structure two distinct biomineralizing processes can occur as a result of the same cellular/metabolic function, spiculogenesis.  相似文献   

5.
Evaluating novel microbe amended composts as biocontrol agents in tomato   总被引:1,自引:0,他引:1  
An investigation was conducted to evaluate the potential of antagonistic cyanobacteria/bacterial cultures amended compost and compost tea preparations for suppressing diseases caused by plant pathogenic fungi Fusarium oxysporum, Pythium debaryanum, Pythium aphanidermatum and Rhizoctonia solani in tomato. Two types of microbe-fortified composts and the compost tea preparations, along with the recommended biological control (Trichoderma formulation) and chemical control (Thiram-Carbendazim), were used for inoculating the potting mixture. Comparative performance of the treatments revealed the superiority of both the composts/compost tea preparations in enhancing seed germination, seedling length and biomass in the fungi challenged treatments. The most effective control of the diseases was obtained by the composts amended with Anabaena oscillarioides C12 and Bacillus subtillis B5 and the compost tea preparations. Both treatments provided significantly better control than the other treatments in terms of reduction in disease severity, reduction of fungal load and enhancement of plant parameters. Our study reveals the efficacy of microbe-fortified composts for use in control of the studied root diseases caused by phytopathogenic fungi.  相似文献   

6.
Because domoic acid, a neurotoxic secondary metabolite produced by marine diatoms in the genus Pseudo-nitzschia, is hypothesized to be part of a high affinity iron uptake system, we investigated whether domoic acid could improve the competitive ability of Pseudo-nitzschia delicatissima, and whether the availability of iron changed the outcome of competition experiments. We found that domoic acid had a slight negative effect on growth of the diatom Skeletonema marinoi when it was grown in monocultures. However, when S. marinoi was cultured with P. delicatissima the presence of domoic acid resulted in a reduction of S. marinoi cells by up to 38% and an increase in P. delicatissima cell numbers by up to 17% under iron replete conditions. Similar effects were not observed in low iron treatments. Domoic acid was not taken up by P. delicatissima cells. Overall, our results indicate that domoic acid can improve the competitive ability of Pseudo-nitzschia spp. and that iron is likely to be involved. This study provides an unusual example of indirect inhibition of competitor growth mediated by a secondary metabolite.  相似文献   

7.
Cyclopeptides usually play a pivotal role, either in the viability or virulence of fungi. Two types of cyclopeptides, six new hydroxamate siderophore cyclohexapeptides (1–6), including acremonpeptides E and F, and their complexes with aluminum and ferric ions; one new cyclic pentapeptolide, aselacin D (9); together with a known compound, aselacin C (10), were isolated and characterized from the sponge-derived fungus Acremonium persicinum F10. In addition, two new siderophore analogues chelating gallium ions (Ga3+), Ga (III)-acremonpeptide E (7) and Ga (III)-acremonpeptide F (8), using isolated acremonpeptides E and F, were prepared. The planar structures of 1–10 were elucidated by HRESIMS and (1D and 2D) NMR. The absolute configurations of amino acids were determined by means of the advanced Marfey’s method and X-ray single-crystal diffraction analysis. X-ray fluorescence (XRF) spectrometer was performed to disclose the elements of compound 1, indicating the existence of aluminum (Al). Al (III)-acremonpeptides E (1), Ga (III)-acremonpeptides E (5), Al (III)-acremonpeptide F (7), and Ga (III)-acremonpeptide F (8) displayed high in vitro anti-fungal activities, which are comparable to amphotericin B, against Aspergillus fumigatus and Aspergillus niger.  相似文献   

8.
In this present study, an organic-inorganic hybrid membrane was prepared by embedding yttrium(III) into chitosan matrix for the removal of Cr(VI) from aqueous solutions. Several techniques, including fourier infrared spectrum (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM) are employed to characterize the properties of the membrane. The mechanical properties of the membrane were also examined. The chitosan/poly(vinyl alcohol) containing yttrium(III) (CY) membrane was experimentally used for the removal of Cr(VI) ions from aqueous solution under the optimized conditions. The results showed that the adsorption capacity for the removal of Cr(VI) ions was enhanced when yttrium(III) was introduced. The adsorption data from the experiment were fit well by Langmuir isotherm. Based on Langmuir model, q m was calculated to be 38.48 mg g?1. Kinetic study results indicated that the adsorption process followed a pseudo-second-order kinetics.  相似文献   

9.
《Field Crops Research》1998,59(3):181-185
The Fe-efficient maize (Zea mays L.) cultivar Alice, the Fe-inefficient mutant yellow-stripe (ys1), and six additional local inbred lines were grown in a growth chamber at 60% relative humidity and 16 h 25°C, 8 h 22°C day–night regime, in nutrient solution with varied Fe supply (+Fe=0.1 mM) or (−Fe=0.01 mM) supplied as Fe(III)–EDTA. The study aimed to establish a genetic assay system for early evaluation of Fe-efficiency and Fe-nutritional status based on peroxidase isozyme variation in roots of maize lines. The wild-type peroxidase isozyme patterns revealed an extra band (C3) not present in the mutant patterns. Inbreds 51, 122, 126, and 137 had peroxidase isozymes similar to the Fe-efficient Alice, while inbreds 112 and 144 had nearly the same pattern as the Fe-inefficient mutant ys1. Sufficient Fe supply did not alter the isoperoxidase patterns of the ys1, but had significant effect on the activity of the (C3) band of the Fe-efficient Alice. On the other hand, the activity of the (C3) band for the inbreds 51, 122, 126 and 137 responded clearly to the sufficient level of iron in the media similar to the response of Alice, while inbreds 112 and 144 did not show any changes in C3 either in sufficient or deficient Fe supply, similar to ys1. The results indicate that the Fe-efficient maize lines may have an additional cathodal (C3) band of the root isoperoxidase and that changes in the activity of the band can reflect the Fe-nutritional status of maize lines.  相似文献   

10.
The condiments and spices consumed in India were analysed for their calcium, phosphorus and iron contents and for the content of total and water-soluble oxalates. A number of spices were found to be quite rich in calcium and also in oxalates. In many of the spices the oxalates were mainly in the insoluble form although a few spices were found to contain oxalates mostly in the water-soluble form. Theoretical calculations on the basis of the calcium and oxalate contents had shown that although the oxalate content is high, a portion of the calcium present in a number of spices may be available to the body. Some of the spices like ajowan (Trachyspermum ammi), turmeric (Curcuma domestica) and caraway seeds (Carum carvi) were also rich in iron. Since some of them are quite inexpensive and, at the same time, rich in calcium and iron, people can be encouraged to consume spices like ajowan (Trachyspermum ammi) to improve the nutritional quality of their diets.  相似文献   

11.
Strain NJES-13T is the type strain and currently the only species of the newly established actinobacteria genera Aptenodytes in the family Dermatophilaceae isolated from the gut microbiota of the Antarctic emperor penguin. This strain demonstrated excellent bioflocculation activity with bacteria-derived exopolysaccharides (EPSs). Moreover, it produced bioactive angucycline/angucyclinone derivatives (ADs) and contained one type III polyketide synthase (T3PKS), thus demonstrating great potential to produce novel bioactive compounds. However, the low productivity of the potential new AD metabolite was the main obstacle for its chemical structure elucidation. In this study, to increase the concentration of targeted metabolites, the influence of cellular morphology on AD metabolism in strain NJES-13T was determined using glass bead-enhanced fermentation. Based on the cellular ultra-structural observation driven by bacterial EPSs, and quantitative analysis of the targeted metabolites, the successful increasing of the productivity of three AD metabolites was achieved. Afterward, a new frigocyclinone analogue was isolated and then identified as 2-hydroxy-frigocyclinone, as well as two other known ADs named 2-hydroxy-tetrangomycin (2-HT) and gephyromycin (GPM). Three AD metabolites were found to demonstrate different bioactivities. Both C-2 hydroxyl substitutes, 2-hydroxy-tetrangomycin and 2-hydroxy-frigocyclinone, exhibited variable inhibitory activities against Staphylococcus aureus, Bacillus subtilis and Candida albicans. Moreover, the newly identified 2-hydroxy-frigocyclinone also showed significant cytotoxicity against three tested human-derived cancerous cell lines (HL-60, Bel-7402 and A549), with all obtained IC50 values less than 10 µM. Based on the genetic analysis after genomic mining, the plausible biogenetic pathway of the three bioactive ADs in strain NJES-13T was also proposed.  相似文献   

12.
The use of Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae), an economical insect model, for the study of enteropathogenic Escherichia coli (Migula) (EPEC), a diarrheagenic human pathogen, has been demonstrated previously but remains poorly understood. The present study characterizes the Galleria-EPEC system extensively for future studies using this system. We found that EPEC causes disease in G. mellonella larvae when injected intrahemocoelically but not orally. Disease manifests as increased mortality, decreased survival time, delayed pupation, decreased pupal mass, increased pupal duration, and hemocytopenia. Disease symptoms are dose-dependent and can be used as metrics for measuring EPEC virulence in future studies. The type III secretion system was only partially responsible for EPEC virulence in G. mellonella while the majority of the virulence remains unknown in origin. EPEC elicits insect anti-bacterial immune responses including melanization, hemolymph coagulation, nodulation, and phagocytosis. The immune responses were unable to control EPEC replication in the early stage of infection (≤3 h post-injection). EPEC clearance from the hemocoel does not guarantee insect survival. Overall, this study provided insights into EPEC virulence and pathogenesis in G. mellonella and identified areas of future research using this system.  相似文献   

13.
14.
Fucosylated chondroitin sulfate (fCS) from sea cucumber Isostichopus badionotus (fCS-Ib) with a chondroitin sulfate type E (CSE) backbone and 2,4-O-sulfo fucose branches has shown excellent anticoagulant activity although has also show severe adverse effects. Depolymerization represents an effective method to diminish this polysaccharide’s side effects. The present study reports a modified controlled Fenton system for degradation of fCS-Ib and the anticoagulant activity of the resulting fragments. Monosaccharides and nuclear magnetic resonance (NMR) analysis of the resulting fragments indicate that no significant chemical changes in the backbone of fCS-Ib and no loss of sulfate groups take place during depolymerization. A reduction in the molecular weight of fCS-Ib should result in a dramatic decrease in prolonging activated partial thromboplastin time and thrombin time. A decrease in the inhibition of thrombin (FIIa) by antithromin III (AT III) and heparin cofactor II (HCII), and the slight decrease of the inhibition of factor X activity, results in a significant increase of anti-factor Xa (FXa)/anti-FIIa activity ratio. The modified free-radical depolymerization method enables preparation of glycosaminoglycan (GAG) oligosaccharides suitable for investigation of clinical anticoagulant application.  相似文献   

15.
Bioavailability to rats of iron from fortified grain amaranth   总被引:1,自引:0,他引:1  
In this study, fortified and unfortified grain amaranth seed flour diets and a FeSO4-fortified casein diet (used as a control) were evaluated for their iron (Fe) bioavailability. NaFeEDTA, ferrous fumarate, and FeSO4-fortified grain amaranth were fed to growing Sprague-Dawley weaning male rats. Iron intake, hemoglobin iron (HbFe) gain, Fe availability, total iron binding capacity (TIBC), serum iron, non-haem liver iron and red bloodcell volume (RBV) were determined, and the values were compared with those of the FeSO4-fortified casein diet control. Ferrous fumarate fortified diets gave consistently high values for all these parameters, compared with consistently low values for the amaranth diet without iron fortification.Relative biological values (RBVs) were 0.40, 1.55, 1.75, 1.67 and 1.00 for animals fed on an unfortified amaranth diet, and diets fortified with NaFeEDTA, ferrous fumarate, FeSO4 and casein fortified with FeSO4, respectively. Using FeSO4-fortified casein as control, ferrous fumarate gave a superior RBVs (1.75 vs. 1.00). The RBVs, of the unfortified cereal diets were 40% that of the control, perhaps suggesting low iron absorption from the amaranth cereal. Based on the results of this study, amaranth cereal can be considered an ideal food vehicle for iron fortification. The iron fortification of choice is ferrous fumarate.  相似文献   

16.
Wheaten pocket-type flat breads were baked from refined flours fortified to contain iron from ferrous sulphate (FeSO4), hydrogen-reduced elemental iron (Fe) or sodium iron ethylenediaminetetraacetic acid (NaFeEDTA). Individual and group visual detection thresholds were determined by the 3-alternative forced choice (3-AFC) test according to the American Society of Testing and Materials (ASTM) method E-1432. The group visual detection thresholds of FeSO4, NaFeEDTA and Fe in bread were established in samples baked from the corresponding wheat flours fortified with 69.46, 236.82 and 304.97 mg iron/kg flour, respectively. Sensory testing showed that iron-fortified pocket-type flat breads were similar (P < 0.01) to regular bread when baked from flours formulated to contain iron at levels lower by 25% than the group visual detection thresholds of Fe and FeSO4 and two 25% increments lower than the threshold of NaFeEDTA. These findings indicate that iron-fortified pocket-type flat breads, which are sensorially similar to regular bread, baked from flours that contained 52.1, 133.22 and 228.73 mg iron/kg flour as FeSO4, NaFeEDTA and Fe, would provide the segment of the population at the highest risk of iron-deficiency anaemia, specifically women of childbearing age, with 91%, 207% and 346% of their recommended daily intakes for iron, respectively.  相似文献   

17.
18.
The study presents a protocol for the preparation of phenolics-saponins rich fraction (PSRF), a new active nutraceutical from defatted rice bran followed by the determination of its antioxidant properties. PSRF was prepared by employing a simple alcoholic fractionation procedure on the crude alcoholic extract (CAE) of defatted rice bran. PSRF was found to be significantly higher in the contents of total phenolic, saponin, and steroidal saponin than CAE and its counterpart, aqueous fraction (AqF) (p < 0.05). Except for iron chelating activity, PSRF exhibited notably higher activity than CAE and AqF in all antioxidant activity assays performed (p < 0.05). HPLC-DAD analysis revealed that PSRF contained substantially higher amounts of gallic acid, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, and ferulic acid than CAE and AqF (p < 0.05). In conclusion, alcoholic fractionation of CAE simultaneously concentrated the phenolic compounds and saponins into PSRF, thus contributed to its higher antioxidant activity. Due to its elevated antioxidant properties, PSRF may be recommended for investigation as an active ingredient in the nutraceutical, functional food, and natural food preservative formulations. This is also the first report suggesting defatted rice bran as a potential and sustainable source of saponins.  相似文献   

19.
Worldwide, the most prevalent nutritional deficiency is iron. The strategies for iron supplementation often fail due to poor adherence to supplementation methods contributed to unpleasant sensory characteristics. An alternative is the use of microencapsulated nutrients for home fortification in order to mask undesirable tastes and to allow its release in strategic sites of the gastrointestinal tract. Toward this end, pea protein concentrate was tested as a natural, edible and alternative material and the spray-drying technique was utilized for the preparation of microparticles containing ferrous sulfate. Their physical and chemical characteristics were evaluated. The microparticles had a spherical shape and grooves with an average size ranging between 2 and 3 μm. Analysis by in vitro assays tested the release of iron in simulated salivary and gastric fluids and its intestinal absorption in Caco-2 cells. No dissolution of iron occurred in the salivary medium whereas the sensory analysis showed good acceptance of a product which incorporated 5.5 mg of iron per 100 g portion of food. Thus, the effectiveness of microencapsulation was demonstrated by utilizing a plant protein as an encapsulating matrix for the controlled release of iron and capable of preserving the bioaccessibility of ferrous sulfate.  相似文献   

20.
The effects of three copper-based fungicides on feeding by four terrestrial molluscs (two slugs and two snails) were assessed in laboratory choice and no-choice tests. These products functioned effectively as short-term feeding deterrents. However, a copper hydroxide-based fungicide was more persistent than copper octanate- and copper diammonia diacetate-based fungicides under field conditions. Tests with foliage treated in the field and fed to Leidyula floridana and Lissachatina fulica showed that significant feeding suppression persisted for several days. We also determined that copper hydroxide was repellent, affecting movement of L. floridana slugs independent of food. Further, we assessed copper hydroxide effects with and without iron phosphate molluscicide bait. Copper hydroxide alone significantly suppressed foliage consumption, but did not affect slug survival. Iron phosphate bait alone caused slug mortality, and significantly suppressed feeding, but only after 24 h. Significantly improved foliage protection, relative to iron phosphate bait application alone, was attained when copper hydroxide repellent was used simultaneously with iron phosphate bait. Where terrestrial molluscs are a plant protection issue, it appears that ancillary benefit can be derived from using copper hydroxide fungicides. These data provide evidence for the potential application of the “push–pull” or “stimulo-deterrent” concept relative to mollusc management; plant protection may be enhanced when attractant and repellent treatments are applied simultaneously.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号